Introduction

Maintenance is a set of operations for: maintaining the rolling stock in working order and proper form; ensuring reliability, efficiency of work, traffic safety, environmental protection; reducing the intensity of deterioration of technical condition parameters, failures and malfunctions, as well as identifying them for the purpose of timely elimination. MOT is a preventive measure carried out compulsorily in a planned manner.

Vehicle maintenance in accordance with the current system is divided into the following types: EO, TO1, TO2, CO; as well as service according to coupons of the car service book.

EO includes cleaning and washing the car, monitoring the technical condition of systems and mechanisms on which traffic safety depends (steering, brake systems, lighting and signaling devices), refueling, monitoring the oil and coolant level in the engine, as well as the level brake fluid in working tanks brake system and a hydraulic clutch.

TO1 in addition to the work of the EO, it includes control and diagnostic, fastening, lubrication and adjustment work in order to prevent accidental failures before the next maintenance, save fuel and other operating materials, as well as reduce environmental pollution.

TO2 in addition to TO1 work, it includes control and diagnostic and adjustment work related to the partial disassembly of the vehicle's components, their removal and checking them on special equipment.

The frequency, lists and procedure for performing maintenance work are given in the factory operating instructions and service books attached to the vehicle upon sale.

The frequency of performance of TO1 and TO2 at automobile transport enterprises for the I category of operating conditions for a temperate climatic region, regulated by the "Regulations on Maintenance and Repair of Rolling Stock of Road Transport".

CO carried out twice a year in order to prepare the car for operation in cold or warm seasons, combining it with the next maintenance, usually with TO2.

Diagnostics is the determination of the technical condition of vehicles, their units and assemblies without disassembly. Diagnostics is a technical element of vehicle maintenance and repair.

The purpose of diagnostics during maintenance is to determine the actual need to perform maintenance work by comparing the actual values ​​of the parameters with the limit values, as well as to assess the quality of the work.

The purpose of diagnostics during repair is to identify malfunctions, the causes of their occurrence and establish the most effective remedy: on-site, with the removal of the unit of a unit or part, with complete or partial disassembly and final quality control of work.

When diagnosing with the help of control and diagnostic tools, diagnostic parameters are determined, which are used to judge the structural parameters that reflect the technical state of the diagnosed mechanism.

A structural parameter is a physical quantity that directly reflects the technical state of the mechanism (geometric shape, dimensions, relative position of the surfaces of parts). Structural parameters, as a rule, cannot be measured without disassembling the mechanism.

A diagnostic parameter is a physical quantity controlled by means of diagnostics and indirectly characterizing the performance of a car or its component (for example, noise, vibration, knocking, decrease in power, pressure.).

The need for an indirect assessment of structural parameters using diagnostic parameters is due to the complexity of direct measurement of structural parameters, since they, as a rule, cannot be measured without disassembling the mechanism. Thus, diagnostics allows you to timely identify malfunctions and prevent sudden failures, reducing losses from vehicle downtime while eliminating unforeseen breakdowns. However, it is necessary to know the relationship between structural and diagnostic parameters.

Distinguish between nominal, permissible, limiting, anticipatory and current values ​​of diagnostic and structural parameters.

The nominal value of the parameter is determined by its design and functional purpose. The nominal values ​​of the parameters are usually new or overhauled mechanisms.

The admissible value of the parameter is called such a boundary value at which the mechanism can maintain its operability and serviceability until the next scheduled control without any additional influences.

The limiting value of the parameter is the largest or the smallest value at which the operability of the mechanism is ensured. When the limiting value of the parameter is reached, further operation of the mechanism is either technically unacceptable or economically inexpedient.

The predictive value of a parameter is called its toughened maximum permissible value, at which a given or economically feasible level of probability of failure-free operation is provided for the upcoming intercontrol operating time.

The current value of the parameter is its actual value at the moment

The following basic diagnostic methods are used:

by the parameters of working processes (for example, by fuel consumption, engine power, braking distance), measured under the conditions closest to operating conditions;

by the parameters of related processes (for example, noise, heating of parts, vibrations), also measured under the conditions closest to the operating conditions;

by structural parameters (for example, clearances, backlash) measured in non-working mechanisms.

Distinguish between complex diagnostics (D1), element-wise diagnostics (D2) and repair diagnostics (Dp).

Comprehensive diagnostics are usually performed at a TO-1 frequency at its final stage. It consists in measuring the main operating parameters of a car that determine the safety and efficiency of its operation, for example, fuel consumption, braking distance, noise level in mechanisms, etc. If the measured parameters are within acceptable limits, the diagnosis is completed, and if not, then the element-by-element diagnosis is performed.

Elemental diagnostics are usually performed before TO-2 for the purpose of a detailed examination of the technical condition of the mechanism and identifying: malfunctions and their causes.

Pre-repair diagnostics is carried out directly during maintenance and repair in order to clarify the need for individual operations.

Qualification characteristic

Car repair mechanic 3rd category

Description of the work. Dismantling of diesel and special trucks and buses over 9.5 m in length. Repair, assembly of trucks, except for special and diesel, passenger cars, buses up to 9.5 m long. Repair and assembly of motorcycles, scooters and other motor vehicles. Fastening of threaded connections during maintenance with replacement of worn parts. Maintenance, cutting, repair, assembly, adjustment and testing of aggregates, assemblies and devices of medium complexity. Repair of units and electrical equipment of cars. Determination and elimination of malfunctions in the operation of units, mechanisms, devices of cars and buses. Connection and soldering of wires with devices and electrical equipment. Locksmith processing, parts according to 11 - 12 qualities with the use of universal devices. Repair and installation of complex units and assemblies under the guidance of a mechanic of higher qualifications.

Must know: device and purpose of units, assemblies and devices of medium complexity; rules for assembling cars and motorcycles, repair of parts, assemblies, assemblies and devices; basic techniques for disassembling, assembling, removing and installing devices and electrical equipment; adjusting and fastening works; typical malfunctions electrical equipment systems, methods of their detection and elimination; purpose and basic properties of materials used in the repair of electrical equipment; the purpose of heat treatment of parts; device of universal special devices and control and measuring instruments; system of tolerances and landings: qualities and roughness parameters.

Work examples

1. Cars, trucks, buses of all brands and types - removal and installation of gas tanks, crankcases, radiators, brake pedals, mufflers, replacement of springs.

2. Cardan shafts, brake drum trunnions - adjustment during assembly.

3. Fans - disassembly, repair, assembly.

4. Cylinder block heads, cardan joints - check, fastening.

5. Cylinder heads of the tipper mechanism - removal, repair, installation.

6. Engines of all types, rear and front axles, transmissions (except automatic), clutches, cardan shafts - disassembly.

7. Contacts - soldering.

8. Fenders of passenger cars - removal, installation.

9. Water pumps, oil pumps, fans, compressors - disassembly, repair, assembly.

10. Winding of insulating devices and electrical equipment units - impregnation, drying.

11. Relay-regulators, ignition distributors - disassembly.

12. Valve seats - sharash machining, lapping.

13. Lights, ignition locks, signals - disassembly, repair, assembly.

Locksmith for fuel equipment 2nd category

Description of the work. Disassembly, repair and assembly of simple units of fuel equipment for carburetor and diesel engines. Dismantling and installation of equipment on carburetor and diesel engines... Adjusting the fuel level in the carburetor float chamber.

Must know: engine arrangement internal combustion; possible malfunctions power supply systems and fuel equipment and methods of their elimination; rules for removing and installing equipment on carburetor and diesel engines; rules for disassembling, repairing, assembling and replacing individual units of fuel equipment.

Work examples.

1. Diesel engines - change of filters of fine and rough cleaning fuel.

2. Jets - disassembly, flushing, purging.

3. Carburettors - repair float, check valve, choke and choke assembly.

4. Carburetors, tanks, sedimentation tanks, nozzles - replacement.

5. Tubes fuel system, nozzle pumps, filters, fuel pumps, booster pumps - replacement.

General information

The service braking system is designed to reduce the speed of the vehicle or bring it to a complete stop. The brakes of the service brake system are installed on all six wheels of the vehicle. The service brake system is driven by a pneumatic double-circuit; it separately actuates the brakes of the front axle and the rear bogie of the vehicle. The drive is controlled by a foot pedal mechanically connected to the brake valve. The executive bodies of the drive of the service brake system are brake chambers.

The spare braking system is designed to smoothly reduce the speed or stop a moving vehicle in the event of a complete or partial failure of the working system.

The parking brake system brakes a stationary vehicle on a horizontal section, as well as on a slope and in the absence of a driver.

The parking brake system on KamAZ vehicles is made as a single unit with a spare one and to turn it on, the handle of the hand valve should be set to the extreme (upper) fixed position.

The emergency release drive provides the possibility of resuming the movement of the vehicle (road train) when it is automatically braked due to a leak of compressed air, alarm and control devices that allow you to monitor the operation of the pneumatic drive.

Thus, in KamAZ vehicles, the rear bogie brakes are common for the working, spare and parking brake systems, and the latter two have, in addition, a common pneumatic drive.

The auxiliary braking system of the vehicle serves to reduce the load and temperature of the braking mechanisms of the service brake system. The auxiliary braking system on KamAZ vehicles is an engine retarder, when turned on, the engine exhaust pipelines are closed and the fuel supply is turned off.

The emergency release system is designed to brake the spring accumulators when they are automatically triggered and the vehicle stops due to a compressed air leak in the drive.

The drive of the emergency release system is duplicated: in addition to the pneumatic drive, there are emergency release screws in each of the four spring brake accumulators, which allows the latter to be released mechanically.

The alarm and control system consists of two parts:

a) light and acoustic signaling about the operation of brake systems and their drives.

At various points of the pneumatic drive, there are built-in pneumo-electric sensors, which, when any braking system, except for the auxiliary one, closes the circuits of the electric brake lights.

Pressure drop sensors are installed in the receivers of the drive and, if there is insufficient pressure in the latter, they close the circuits of the signaling electric lamps located on the dashboard of the car, as well as the circuit sound signal(buzzer).

b) valves of control outputs, with the help of which the technical condition of the pneumatic brake drive is diagnosed, as well as (if necessary) the selection of compressed air.

Figure 1 shows a diagram of the pneumatic drive of the brake mechanisms of KamAZ vehicles.

The source of compressed air in the drive is compressor 9. Compressor, pressure regulator 11, fuse 12 against condensate freezing, condensation receiver 20 constitute the supply part of the drive, from which purified compressed air at a given pressure is supplied in the required amount to the remaining parts of the pneumatic brake drive and to others compressed air consumers.

The pneumatic brake actuator is divided into autonomous circuits, separated from each other by safety valves. Each circuit operates independently of the other circuits, even in the event of a malfunction. The pneumatic brake actuator consists of five circuits, separated by one double and one triple safety valve.

The circuit I of the drive of the working brakes of the front axle consists of a part of the triple safety valve 17; a receiver 24 with a capacity of 20 liters with a condensate drain cock and a pressure drop sensor 18 in the receiver, part of a two-pointer manometer 5; the lower section of the two-piece brake valve 16; valve 7 of the control outlet (C); pressure limiting valve 8; two brake chambers 1; brake mechanisms of the front axle of the tractor; pipes and hoses between these devices.

In addition, the circuit includes a pipeline from the lower section of the brake valve 16 to the valve 81 for controlling the trailer braking systems with a two-line drive.

The circuit II of the drive of the working brakes of the rear bogie consists of a part of the triple safety valve 17; receivers 22 with a total capacity of 40 liters with condensate drain valves 19 and a pressure drop sensor 18 in the receiver; parts of a two-pointer manometer 5; the upper section of the two-piece brake valve 16; control output valve (D) of the automatic brake force regulator 30 with an elastic element; four brake chambers 26; rear bogie brakes (intermediate and rear axles); piping and hose between these devices. The circuit also includes a pipeline from the upper section of the brake valve 16 to the brake control valve 31 with a two-line drive.

The circuit III of the drive of the mechanisms of the spare and parking brake systems, as well as the combined drive of the trailer (semi-trailer) brake mechanisms, consists of a part of the double safety valve 13; two receivers 25 with a total capacity of 40 liters with a condensate drain valve 19 and a pressure drop sensor 18 in the receivers; two valves 7 of the control output (B and E) of the hand brake valve 2, an accelerating valve 29; parts of the two-line bypass valve 32; four spring brake accumulators 28 brake chambers; pressure drop sensor 27 in the line of spring brake accumulators; valve 31 control the brakes of the trailer with a two-wire drive; single safety valve 35; valve 34 control the brakes of the trailer with a single-line drive; three disconnecting valves 37 three connecting heads; heads 38 of type A of a single-wire drive of trailer brakes and two heads of 39 type "Palm" of a two-wire drive of trailer brakes; two-wire drive of trailer brakes; pneumo-electric sensor 33 "brake light", pipelines and hoses between these devices. It should be noted that the pneumo-electric sensor 33 in the circuit is installed in such a way that it ensures that the "stoplight" lamps are switched on when the vehicle is braking not only with the spare (parking) brake system, but also with the working one, as well as in the event of failure of one of the circuits of the latter ...

The circuit IV of the drive of the auxiliary brake system and other consumers does not have its own receiver and consists of a part of the double safety valve 13; pneumatic valve 4; two cylinders 23 to drive the flaps; cylinder 10 drive the engine stop lever; pneumo-electric sensor 14; pipes and hoses between these devices. From circuit IV of the drive of the mechanisms of the auxiliary brake system, compressed air is supplied to additional (not brake) consumers; pneumatic signal, pneumohydraulic clutch booster, control of transmission units, etc.

The V circuit of the emergency release drive does not have its own receiver and executive bodies. It consists of a triple safety valve part 17; pneumatic valve 4; parts of the two-line bypass valve 32; pipelines and hoses connecting devices.

Figure 1 - Diagram of the pneumatic drive of the brake mechanisms of KamAZ-5320 vehicles

1 - type 24 brake chambers; 2 (A, B, C) - test leads; 3 - pneumo-electric switch of the trailer solenoid valve; 4 - auxiliary brake system control valve; 5 - two-pointer manometer; 6 - compressor 7 - pneumatic cylinder of the engine stop lever drive; 8 - water separator; 9 - pressure regulator; 11 - two-line bypass valve; 12-4 circuit safety valve; 13 - parking brake control valve; 14 - heat exchanger; 15 - two-section brake valve; 17 - pneumatic cylinders for flap drive of the auxiliary brake system mechanism; 18 - receiver of circuit I; 19 - consumer receiver; 20 - pressure drop indicator switch; 21 - receiver of circuit III; 22 - receivers of circuit II; 23 - condensate drain valve; 24 - brake chambers of type 20/20 with spring brake accumulators; 25, 28 - accelerating valves; 26 - valve for controlling the brake systems of the trailer with a two-wire drive; 27 - switch of the parking brake system indicator; 29 - valve for controlling the braking systems of the trailer with a single-line drive; 30 - automatic connecting heads; 31 - type A connection head; R - to the supply line of the two-wire drive; P - to the connecting line of the single-wire drive; N - to the control line of the two-wire drive; 31- pressure drop sensor in the receivers of the primary circuit; 32 - pressure drop sensor in the receivers of the second circuit; 33-sensor brake light; 34-valve for emergency release

Pneumatic brake drives of the tractor and trailer connect three lines: a single-wire drive line, supplying and control (brake) lines of a two-wire drive. On truck tractors the connecting heads 38 and 39 are located at the ends of the three flexible hoses of these lines, which are attached to the supporting rod. On on-board vehicles heads 38 and 39 are mounted on the rear cross member of the frame.

To monitor the operation of the pneumatic brake drive, and timely signal its condition, and malfunctions in the cab, there are five warning lights on the instrument panel, a two-pointer pressure gauge showing the compressed air pressure in the receivers of two circuits (I and II) of the pneumatic drive of the service brake system , and a buzzer signaling an emergency drop in compressed air pressure in the receivers of any brake drive circuit.

Brakes (Figure 3) are installed on all six wheels of the vehicle, the main brake unit is mounted on a caliper 2 rigidly connected to the axle flange. On the eccentrics of the axles 1, fixed in the caliper, two brake pads 7 are freely supported with friction linings 9 attached to them, made along a crescent profile in accordance with the nature of their wear. The axles of the pads with eccentric bearing surfaces allow the pads to be correctly centered relative to the brake drum when assembling the brakes. The brake drum is attached to the wheel hub with five bolts.

When braking, the pads are pushed apart by an S-shaped fist 12 and pressed against the inner surface of the drum. Rollers 13 are installed between the expander 12 and the pads 7, which reduce friction and improve the braking efficiency. The pads are returned to the braked state by four release springs 8.

Expanding fist 12 rotates in a bracket 10, bolted to the caliper. The brake chamber is mounted on this bracket. At the end of the expander shaft, a worm-type adjusting lever 14 is installed, connected to the brake chamber rod by means of a fork and a pin. A shield bolted to the caliper protects the brake from dirt.

Figure 2 - Brake mechanism

1 - the axis of the shoe; 2 - support; 3 - shield; 4 - axle nut; 5 - lining of the axes of the pads; 6 - check of the axis of the pads; 7 - brake shoe; 8 - spring; 9 - friction pad; 10-expander bracket; 11 - roller axis; 12 - expanding fist; 13 - roller; 14 - adjusting lever

The adjusting lever is designed to reduce the gap between the pads and brake drum increasing due to wear of the friction linings. The device of the adjusting lever is shown in Figure 4. The adjusting lever has a steel body 6 with a sleeve 7. The body contains a worm gear 3 with slotted holes for installation on an expanding fist and a worm 5 with an axis pressed into it 11. There is a locking device for fixing the worm axis , the ball 10 of which enters the holes on the axis 11 of the worm under the action of the spring 9, abutting against the locking bolt 8. The gear wheel is kept from falling out by covers 1 attached to the housing 6 of the lever. When the axle is turned (by the square end), the worm turns wheel 3, and with it the expander rotates, pushing the pads apart and reducing the gap between the pads and the brake drum. When braking, the adjusting lever is turned by the brake chamber rod.

Before adjusting the gap, the locking bolt 8 must be loosened by one or two turns, after adjusting the bolt, tighten it securely.

Figure 3 - Adjusting lever

1 - cover; 2 - rivet; 3 - gear wheel; 4 - plug; 5 - worm; 6 - case; 7 - bushing; 8 - locking bolt; 9 - retainer spring; 10 - retainer ball; 11 - the axis of the worm; 12 - oiler

The mechanism of the auxiliary braking system is shown in Figure 4.

In the exhaust pipes of the muffler, a housing 1 and a damper 3 are installed, fixed on the shaft 4. A rotary lever 2 is also attached to the damper shaft, connected to the rod of the pneumatic cylinder. Lever 2 and the associated shutter 3 have two positions. The inner cavity of the body is spherical. When the auxiliary braking system is turned off, the flap 3 is installed along the flow of the exhaust gases, and when turned on, it is perpendicular to the flow, creating a certain back pressure in the exhaust manifolds. At the same time, the fuel supply is cut off. The engine starts running in compressor mode.

Figure 4 - The mechanism of the auxiliary braking system

1 - case; 2 - rotary lever; 3 - damper; 4 - shaft. The compressor (Figure 5) is a piston-type, single-cylinder, single-stage compression. The compressor is attached to the front end of the engine flywheel housing.

Aluminum piston with floating pin. From axial movement, the pin in the piston bosses is fixed with thrust rings. Air from the engine manifold enters the compressor cylinder through the intake plate valve.

The air compressed by the piston is forced into the pneumatic system through a lamellar discharge valve located in the cylinder head.

The head is cooled by liquid supplied from the engine cooling system. Oil is supplied to the rubbing surfaces of the compressor from the engine oil line: to the rear end of the compressor crankshaft and through the crankshaft channels to the connecting rod. The piston pin and cylinder walls are spray lubricated.

When the pressure in the pneumatic system reaches 800–2000 kPa, the pressure regulator communicates the discharge line with the environment, stopping the air supply to the pneumatic system.

When the air pressure in the pneumatic system drops to 650-50 kPa, the regulator closes the air outlet to the environment and the compressor starts pumping air into the pneumatic system again.

Figure 5 - Compressor

1- connecting rod; 2 - piston pin; 3 - oil scraper ring; 4 - compression ring; 5 - compressor cylinder case; 6 - cylinder spacer; 7 - cylinder head; 8 - tie bolt; 9 - nut; 10 - gaskets; 11 - piston; 12, 13 - sealing rings; 14 - sleeve bearings; 15 - rear crankcase cover; 16 - crankshaft; 17 - crankcase; 18 - toothed wheel of the drive; 19 - nut for fastening the gear wheel; I - input; II - output to the pneumatic system

The moisture separator is designed to separate condensate from the compressed air and automatically remove it from the supply part of the drive. The structure of the water separator is shown in Figure 6.

Compressed air from the compressor through inlet II is supplied to the finned aluminum cooler tube (radiator) 1, where it is constantly cooled by the oncoming air flow. Then the air passes along the centrifugal guide discs of the guide vane 4 through the hole of the hollow screw 3 in the housing 2 to port I and then to the pneumatic brake actuator. The moisture released due to the thermodynamic effect, flowing through the filter 5, accumulates in the lower cover 7. When the regulator is triggered, the pressure in the moisture separator drops, while the membrane 6 moves up. The condensate drain valve 8 opens, the accumulated mixture of water and oil is discharged into the atmosphere through port III.

The direction of the compressed air flow is shown by arrows on the housing 2.

Figure 6 - Moisture separator

1 - radiator with finned tubes; 2 - case; 3 - hollow screw; 4 - guiding apparatus; 5 - filter; 6 - membrane; 7 - cover; 8 - condensate drain valve; I - to the pressure regulator; II - from the compressor; III - into the atmosphere

The pressure regulator (figure 7) is intended:

- to regulate the pressure of compressed air in the pneumatic system;

- protection of the pneumatic system from overloading by excessive pressure;

- cleaning compressed air from moisture and oil;

- ensuring tire inflation.

Compressed air from the compressor through port IV of the regulator, filter 2, channel 12 is fed into the annular channel. Through the check valve 11, compressed air is supplied to port II and further to the receivers of the pneumatic system of the vehicle. At the same time, compressed air flows through channel 9 under piston 8, which is loaded with a balancing spring 5. In this case, the exhaust valve 4, which connects the cavity above the unloading piston 14 to the atmosphere through port I, is open, and the inlet valve 13 is closed under the action of the spring. The unloader valve 1 is also closed by the action of the spring. In this state of the regulator, the system is filled with compressed air from the compressor. When the pressure in the cavity under the piston 8 is equal to 686.5 ... 735.5 kPa (7 ... 7.5 kgf / cm2), the piston, overcoming the force of the balancing spring 5, rises, valve 4 closes, the inlet valve 13 opens.

Under the action of compressed air, the unloading piston 14 moves downward, the unloading valve 1 opens, and the compressed air from the compressor through port III is released into the atmosphere together with the condensate accumulated in the cavity. In this case, the pressure in the annular channel drops and the check valve 11 closes. Thus, the compressor operates in unloaded mode without back pressure.

When the pressure in port II drops to 608 ... 637.5 kPa, piston 8 moves downward under the action of spring 5, valve 13 closes, and outlet valve 4 opens. In this case, the unloading piston 14 under the action of the spring rises up, the valve 1 is closed under the action of the spring, and the compressor pumps compressed air into the pneumatic system.

The unloading valve 1 also serves as a safety valve. If the regulator does not work at a pressure of 686.5 ... 735.5 kPa (7 ... 7.5 kgf / cm2), then valve 1 opens, overcoming the resistance of its spring and the spring of the piston 14. Valve 1 opens at a pressure of 980, 7 ... 1274.9 kPa (10 ... 13 kgf / cm2). The opening pressure is adjusted by changing the number of gaskets installed under the valve spring.

To connect special devices, the pressure regulator has an outlet, which is connected to outlet IV through a filter 2. This outlet is closed with a screw plug 3. In addition, there is an air take-off valve for tire inflation, which is closed with a cap 17. When screwing on the fitting of the tire inflation hose, the valve is recessed , opening access to compressed air in the hose and blocking the passage of compressed air into the brake system. Before inflating the tires, the pressure in the receivers should be reduced to a pressure corresponding to the activation pressure of the regulator, since during idle move air sampling cannot be performed.

Figure 7 - Pressure regulator

1 - unloading valve; 2 - filter; 3 - plug of the air bleed channel; 4 - outlet valve; 5 - balancing spring; 6 - adjusting screw; 7 - protective cover; 8 - servo piston; 9, 10, 12 - channels; 11 - check valve; 13 - inlet valve; 14 - unloading piston; 15 - unloading valve saddle; 16 - valve for tire inflation; 17 -cap; I, III - atmospheric conclusions; II - into the pneumatic system; IV - from the compressor; C - cavity under the follower piston; D - cavity under the unloading piston

The two-section brake valve (Figure 8) is used to control the actuators of the dual-circuit drive of the vehicle's service brake system.

Figure 8 - Pedal-operated brake valve

1 - pedal; 2 - an adjusting bolt; 3 - protective cover; 4 - roller axis; 5 - roller; 6 - pusher; 7 - base plate; 8 - nut; 9 - plate; 10,16, 19, 27 - sealing rings; 11 - hairpin; 12 - spring of the follower piston; 13, 24 - valve springs; 14, 20 - valve spring plates; 15 - small piston; 17 - valve of the lower section; 18 - small piston pusher; 21 - atmospheric valve; 22 - thrust ring; 23 - atmospheric valve body; 25 - lower case; 26 - small piston spring; 28 - large piston; 29 - valve of the upper section; 30 - tracking piston; 31 - elastic element; 32 - upper case; A - hole; B - cavity above the large piston; I, II - input from the receiver; III, IV - output to the brake chambers, respectively, of the rear and front wheels

The crane is controlled by a pedal directly connected to the brake valve.

The crane has two independent sections in series. Inputs I and II of the valve are connected to the receivers of two separate circuits of the working brake system drive. From terminals III and IV, compressed air flows to the brake chambers. When you press the brake pedal, the force is transmitted through the pusher 6, the plate 9 and the elastic element 31 to the follower piston 30. Moving downward, the follower piston 30 first closes the outlet of the valve 29 of the upper section of the brake valve, and then detaches the valve 29 from the seat in the upper body 32, opening the passage of compressed air through inlet II and outlet III and further to the actuators of one of the circuits. The pressure at port III increases until the force of pressing the pedal 1 is balanced by the force created by this pressure on the piston 30. This is how the follow-up action is carried out in the upper section of the brake valve. Simultaneously with the increase in pressure at port III, compressed air through hole A enters the cavity B above the large piston 28 of the lower section of the brake valve. Moving downward, the large piston 28 closes the valve outlet 17 and lifts it from the seat in the lower housing. Compressed air flows through input I to port IV and further to the actuators of the primary circuit of the working brake system.

Simultaneously with the increase in pressure at port IV, the pressure under the pistons 15 and 28 increases, as a result of which the force acting on the piston 28 from above is balanced. As a result, at port IV, a pressure is also established that corresponds to the force on the brake valve lever. This is how the follow-up action is carried out in the lower section of the brake valve.

In case of failure of the upper section of the brake valve, the lower section will be mechanically controlled through the pin 11 and the pusher 18 of the small piston 15, fully maintaining its operability. In this case, the follow-up action is carried out by balancing the force applied to the pedal 1 by the air pressure on the small piston 15. If the lower section of the brake valve fails, the upper section works as usual.

The automatic brake force regulator is designed to automatically regulate the pressure of compressed air supplied during braking to the brake chambers of the axles of the rear bogie of KamAZ vehicles, depending on the acting axle load.

The automatic brake force regulator is installed on the bracket 1, fixed on the cross member of the vehicle frame (Figure 9). The regulator is fastened to the bracket with nuts.

Figure 9 - Installing the brake force regulator

1 - regulator bracket; 2 - regulator; 3- lever; 4 - the rod of the elastic element; 5 - elastic element; 6 - connecting rod; 7 - compensator; 8 - intermediate bridge; 9 - rear axle

The lever 3 of the regulator by means of a vertical rod 4 is connected through an elastic element 5 and a rod 6 with the beams of the axles 8 and 9 of the rear bogie. The regulator is connected to the axles in such a way that the distortion of the axles during braking on uneven roads and twisting of the axles due to the action of the braking torque do not affect the correct regulation of the braking forces. The regulator is installed in a vertical position. The length of the lever arm 3 and its position with the unloaded axle are selected according to a special nomogram, depending on the suspension travel when the axle is loaded and the ratio of the axle load in the loaded and unladen state.

The device of the automatic brake force regulator is shown in Figure 10. When braking, compressed air from the brake valve is supplied to port I of the regulator and acts on the upper part of the piston 18, forcing it to move downward. At the same time, compressed air through the tube 1 enters under the piston 24, which moves upward and is pressed against the pusher 19 and the ball heel 23, which is together with the regulator lever 20 in a position that depends on the load on the bogie axle. When the piston 18 moves down, the valve 17 is pressed against the outlet seat of the pusher 19. With further movement of the piston 18, the valve 17 breaks off from the seat in the piston and compressed air from port I enters port II and further to the brake chambers of the rear bogie bogies.

At the same time, the compressed air through the annular gap between the piston 18 and the guide 22 enters the cavity A under the membrane 21 and the latter begins to press on the piston from below. When the pressure at port II is reached, the ratio of which to the pressure at port I corresponds to the ratio of the active areas of the upper and lower sides of the piston 18, the latter rises up until the valve 17 lands on the inlet seat of the piston 18. The flow of compressed air from port I to port II stops. Thus, the follow-up action of the regulator is carried out. The active area of ​​the upper side of the piston, which is affected by the compressed air supplied to port 7, remains always constant.

The active area of ​​the lower side of the piston, which is influenced by the compressed air passed to port II through the membrane 21, is constantly changing due to the change in the relative position of the inclined ribs 11 of the moving piston 18 and the stationary insert 10. The relative position of the piston 18 and the insert 10 depends on the position of the lever 20 and associated with it through the heel 23 of the pusher 19. In turn, the position of the lever 20 depends on the deflection of the springs, that is, on the relative position of the axle beams and the car frame. The lower the lever 20, the heel 23, and, consequently, the piston 18, is lowered, the larger the area of ​​the ribs 11 comes into contact with the membrane 21, that is, the larger the active area of ​​the piston 18 from below becomes. Therefore, at the extreme lower position of the pusher 19 (minimum axial load), the difference in pressures of compressed air in ports I and II is greatest, and at the extreme upper position of the pusher 19 (maximum axial load), these pressures are equalized. Thus, the brake force regulator automatically maintains a compressed air pressure in port II and in the associated brake chambers, which provides the required braking force, proportional to the axial load acting during braking.

When braking, the pressure at port I drops. The piston 18, under the pressure of compressed air acting on it through the membrane 21 from below, moves upward and detaches the valve 17 from the outlet seat of the pusher 19. The compressed air from port II exits through the opening of the pusher and port III into the atmosphere, squeezing the edges of the rubber valve 4.

Figure 10 - Automatic brake force regulator

1 -pipe; 2, 7 - sealing rings; 3 - lower body; 4 - valve; 5 - shaft; 6, 15 - persistent rings; 8 - membrane spring; 9 - membrane washer; 10 - insert; 11 - ribs of the piston; 12 - cuff; 13 - valve spring plate; 14 - upper case; 16 - spring; 17 - valve; 18 - piston; 19 - pusher; 20 - lever; 21 - membrane; 22 - guide; 23 - ball heel; 24 - piston; 25 - guide cap; I - from the brake valve; II - to the brake chambers of the rear wheels; III - into the atmosphere

The elastic element of the brake force regulator is designed to prevent damage to the regulator if the movement of the axles relative to the frame is greater than the permissible travel of the regulator lever.

The elastic element 5 of the brake force regulator is installed (Figure 11) on the rod 6, located between the beams of the rear axles in a certain way.

The connection point of the element with the rod 4 of the regulator is located on the axis of symmetry of the bridges, which does not move in the vertical plane when the bridges are twisted during braking, as well as with a one-sided load on an uneven road surface and when bridges are skewed on curved sections when turning. Under all these conditions, only vertical displacements from static and dynamic changes in axial load are transmitted to the regulator lever.

The design of the elastic element of the brake force regulator is shown in Figure 11. With vertical displacements of the axles within the permissible stroke of the lever of the brake force regulator, the ball pin 4 of the elastic element is at the neutral point. With strong shocks and vibrations, as well as when the axles are moved beyond the permissible stroke of the lever of the brake force regulator, the rod 3, overcoming the force of the spring 2, turns in the body 1. At the same time, the rod 5, which connects the elastic element with the brake force regulator, rotates relative to the deflected rod 3 around the ball pin 4.

After the cessation of the force that deflects the rod 3, the pin 4 under the action of the spring 2 returns to its original neutral position.

Figure 11 - Elastic element of the brake force regulator

1 - case; 2 - spring; 3 - rod; 4 - ball finger; 5 - control rod

The four-circuit safety valve (Figure 12) is designed to separate the compressed air coming from the compressor into two main and one additional circuits: to automatically shut off one of the circuits in case of violation of its tightness and preserve the compressed air in sealed circuits; to preserve compressed air in all circuits in case of violation of the tightness of the supply line; to supply an additional circuit from two main circuits (until the pressure in them drops to a predetermined level).

A four-way safety valve is attached to the vehicle frame side member.

Figure 12 - Four-circuit safety valve

1 - protective cap; 2 - spring plate; 3, 8, 10 - springs; 4 - spring guide; 5 - membrane; 6 - pusher; 7, 9 - valves; 11, 12 - screws; 13 - transport plug; 14 - case; 15 - cover

Compressed air entering the four-circuit safety valve from the supply line, upon reaching a predetermined opening pressure set by the force of the springs 3, opens the valves 7, acting on the membrane 5, lifts it, and enters through the outputs into the two main circuits. After opening the check valves, compressed air enters the valves 7, opens them and passes through the outlet into an additional circuit.

If the tightness of one of the main circuits is broken, the pressure in this circuit, as well as at the inlet to the valve, drops to a predetermined value. As a result, the valve of the healthy circuit and the check valve of the additional circuit are closed, preventing a decrease in pressure in these circuits. Thus, in serviceable circuits, the pressure corresponding to the opening pressure of the valve of the defective circuit will be maintained, while the excess amount of compressed air will exit through the defective circuit.

If the additional circuit fails, the pressure drops in the two main circuits and at the valve inlet. This happens until the valve 6 of the additional circuit is closed. With the further flow of compressed air into the safety valve 6 in the main circuits, the pressure will be maintained at the level of the opening pressure of the additional circuit valve.

Receivers are designed to accumulate compressed air produced by the compressor, and to supply it to pneumatic brake drive devices, as well as to supply other pneumatic components and systems of the vehicle.

Six receivers with a capacity of 20 liters are installed on a KamAZ car, and four of them are connected in pairs, forming two tanks with a capacity of 40 liters. The receivers are fixed with clamps on the vehicle frame brackets. Three receivers are combined into a unit and mounted on a single bracket.

The condensate drain valve (Figure 13) is designed for forced drainage of condensate from the receiver of the pneumatic brake drive, as well as for releasing compressed air from it, if necessary. The condensate drain cock is screwed into the threaded boss on the bottom of the receiver housing. The connection between the tap and the receiver boss is sealed with a gasket.

Figure 13 - Condensate drain valve

1 - stock; 2 - spring; 3 - case; 4 - support ring; 5 - washer; 6 - valve

A brake chamber with a 20/20 type spring accumulator is shown in Figure 14. It is designed to actuate the braking mechanisms of the wheels of the rear bogie of a car when the working, spare and parking brake systems are activated.

The spring brake accumulators together with the brake chambers are mounted on the brackets of the expansion cams of the rear bogie brakes and are secured with two nuts and bolts.

When braking by the service brake system, compressed air from the brake valve is supplied to the cavity above the membrane 16. The membrane 16, bending, acts on the disc 17, which moves the rod 18 through the washer and the lock nut and turns the adjusting lever with the brake expander fist. Thus, the braking of the rear wheels is the same as the braking of the front wheels with a conventional brake chamber.

When the spare or parking brake system is turned on, that is, when the air is released by the manual valve from the cavity under the piston 5, the spring 8 is expanded and the piston 5 moves downward. The thrust bearing 2 through the membrane 16 acts on the thrust bearing of the rod 18, which, while moving, turns the associated adjusting lever of the brake mechanism. The vehicle brakes.

When braking, compressed air enters through the outlet under the piston 5. The piston, together with the pusher 4 and the thrust bearing 2, moves upward, compressing the spring 8 and allows the brake chamber rod 18 under the action of the return spring 19 to return to starting position.

Figure 14 - Brake chamber type 20/20 with a spring brake

1 - case; 2 - thrust bearing; 3 - sealing ring; 4 - pusher; 5 - piston; 6 - piston seal; 7 - power accumulator cylinder; 8 - spring; 9 - screw of the emergency release mechanism; 10 - persistent nut; 11- cylinder branch pipe; 12 - drainage tube; 13 - thrust bearing; 14 - flange; 15 - brake chamber pipe; 16 - membrane; 17 - supporting disk; 18 - stock; 19 - return spring

When excessively large gap between the pads and the brake drum, that is, with an excessively large stroke of the brake chamber rod, the force on the rod may be insufficient for effective braking. In this case, you should enable hand brake check valve and release air from under the piston 5 of the spring accumulator. The foot bearing 2, under the action of the force spring 8, will push the middle of the membrane 16 and advance the rod 18 by the available additional stroke, ensuring the braking of the car.

If the tightness is broken and the pressure in the receiver of the parking brake system drops, the air from the cavity under the piston 5 through the outlet will go into the atmosphere through the damaged part of the drive and the car will be automatically braked by spring brake accumulators.

Pneumatic cylinders are designed to actuate the mechanisms of the auxiliary brake system.

Three pneumatic cylinders are installed on KamAZ vehicles:

- two cylinders with a diameter of 35 mm and a piston stroke of 65 mm (Figure 15), a) for control throttle valves installed in the exhaust pipes of the engine;

- one cylinder with a diameter of 30 mm and a piston stroke of 25 mm (Figure 15, b) to control the high pressure fuel pump regulator lever.

Pneumatic cylinder 035x65 is hinged to the bracket with a pin. The cylinder rod is connected by a threaded fork to the choke control lever. When the auxiliary brake system is turned on, compressed air from the pneumatic valve through the outlet in the cover 1 (see Fig. 311, a) enters the cavity under the piston 2. Piston 2, overcoming the force of the return springs 3, moves and acts through the rod 4 on the flap control lever by moving it from the "OPEN" position to the "CLOSED" position. When the compressed air is released, the piston 2 with the rod 4 returns to its original position under the action of the springs 3. In this case, the damper is turned to the "OPEN" position.

Pneumatic cylinder 030x25 is pivotally mounted on the high pressure fuel pump regulator cover. The cylinder rod is connected to the regulator lever by a threaded fork. When the auxiliary brake system is turned on, compressed air from the pneumatic valve through the outlet in the cylinder cover 1 enters the cavity under the piston 2. Piston 2, overcoming the force of the return spring 3, moves and acts through the rod 4 on the fuel pump regulator lever, bringing it to the zero feed position ... The pedal linkage is linked to the cylinder rod so that the pedal does not move when the auxiliary braking system is engaged. When the compressed air is released, the piston 2 with the rod 4 returns to its original position under the action of the spring 3.

Figure 15 - Pneumatic cylinders for the damper drive of the auxiliary brake system mechanism (a) and the drive for the engine stop lever (b)

1 - cylinder cover; 2 - piston; 3 - returnable springs; 4 - stock; 5-case; 6 - cuff

The control outlet valve (Fig. 312) is designed to be connected to the drive of control and measuring instruments in order to check the pressure, as well as to take compressed air. Five such valves are installed on KamAZ vehicles - in all circuits of the pneumatic brake drive. To connect to the valve, use hoses and gauges with union nut M 16x1.5.

When measuring pressure or for taking compressed air, unscrew the valve cap 4 and screw on the body 2 the union nut of the hose connected to the control pressure gauge or to some consumer. When screwing on, the nut moves the pusher 5 with the valve, and air enters the hose through the radial and axial holes in the pusher 5. After disconnecting the hose, the pusher 5 with the valve under the action of the spring 6 is pressed against the seat in the housing 2, closing the outlet of compressed air from the pneumatic actuator.

Figure 16 - Test outlet valve

1 - fitting; 2 - case; 3 - loop; 4 - cap; 5 - a pusher with a valve; 6 - spring

The pressure drop sensor (Figure 17) is a pneumatic switch designed to close the circuit of electric lamps and the sound signal (buzzer) of the alarm when the pressure drops in the reservoirs of the pneumatic brake drive. The sensors are screwed into the receivers of all brake drive circuits with the help of an external thread on the body, as well as into the valves of the drive circuit of the parking and spare brake systems, and when they are turned on, the red indicator light on the instrument panel and the brake signal lamp light up.

The sensor has normally closed central contacts that open when the pressure rises above 441.3 ... 539.4 kPa.

When the specified pressure is reached in the drive, the diaphragm 2 bends under the action of compressed air and through the pusher 4 acts on the movable contact 5. The latter, overcoming the force of the spring 6, breaks off from the fixed contact 3 and breaks the electrical circuit of the sensor. Closing the contact, and consequently turning on the control lamps and the buzzer, occurs when the pressure drops below the specified value.

Figure 17 - Pressure drop sensor

1 - case; 2 -membrane; 3 - fixed contact; 4 pusher; 5 - movable contact; 6 - spring; 7 - adjusting screw; 8 - insulator

The brake light switch (figure 18) is a pneumatic switch designed to close the circuit of electric warning lamps during braking. The sensor has normally open contacts that close at a pressure of 78.5 ... 49 kPa and open when the pressure drops below 49 ... 78.5 kPa. The sensors are installed in the lines supplying compressed air to the actuators of the brake systems.

When compressed air is supplied under the membrane, the membrane bends, and the movable contact 3 connects the contacts 6 of the electrical circuit of the sensor.

Figure 18 - Sensor for turning on the brake signal

1 - case; 2-membrane; 3 - contact is movable; 4 -spring; 5 - output of a fixed contact; 6 - fixed contact; 7 - cover

The trailer brake control valve with a two-wire drive (Figure 19) is designed to actuate the trailer (semitrailer) brake drive when any of the separate drive circuits of the working brake system of the tractor is turned on, as well as when the spring accumulators of the drive of the spare and parking brake systems of the tractor are turned on.

The valve is attached to the tractor frame with two bolts.

A membrane 1 is clamped between the lower 14 and middle 18 housings, which is fixed between two washers 17 on the lower piston 13 by a nut 16 sealed with a rubber ring. An outlet port 15 with a valve that protects the device from dust and dirt is attached to the lower body with two screws. When one of the screws is loosened, the outlet window 15 can be rotated and access to the adjusting screw 8 through the opening of valve 4 and piston 13. In the released state, compressed air is constantly supplied to ports II and V, which, acting on the top of the membrane 1 and from the bottom of the middle piston 12, holds the piston 13 in the lower position. In this case, terminal IV connects the trailer brake control line with atmospheric terminal VI through the central opening of the valve 4 and the lower piston 13.

Figure 19 - Trailer brake control valve with two-wire drive

1 - membrane; 2 -spring; 3 - unloading valve; 4 - inlet valve; 5 - upper body; 6 - large upper piston; 7 - spring plate; 8 - adjusting screw; 9 - spring; 10 - small upper piston; 11 - spring; 12 - medium piston; 13 - lower piston; 14 - lower body; 15 - outlet window; 16 - nut; 17 - membrane washer; 18 - medium body; I - output to the section of the brake valve;

II - output to the parking brake control valve; III - output to the section of the brake valve; IV - output to the brake line of the trailer; V - output to the receiver; VI - atmospheric output

When compressed air is supplied to port III, the upper pistons 10 and 6 move down simultaneously. Piston 10 first sits with its seat on valve 4, blocking the atmospheric outlet in the lower piston 13, and then detaches valve 4 from the seat of the middle piston 12. Compressed air from the V port connected to the receiver enters port IV and then into the brake control line trailer. The supply of compressed air to port IV continues until its effect from below on the upper pistons 10 and 6 is balanced by the pressure of compressed air supplied to port III on these pistons from above. After that, valve 4, under the action of spring 2, blocks the access of compressed air from port V to port IV. Thus, the follow-up action is carried out. With a decrease in the compressed air pressure at port III from the brake valve, i.e. when braking, the upper piston 6 under the action of the spring 11 and the pressure of compressed air from below (in port IV) moves upward together with the piston 10. The seat of the piston 10 breaks off from valve 4 and communicates port IV with atmospheric outlet VI through the openings of valve 4 and piston 13.

When compressed air is supplied to port I, it flows under the membrane 1 and moves the lower piston 13 together with the middle piston 12 and valve 4 upward. The valve 4 reaches the seat in the small upper piston 10, closes the atmospheric outlet, and with further movement of the middle piston 12 is torn off from its inlet seat. Air flows from the V port, connected to the receiver, to the IV port and further to the trailer brake control line until its effect on the middle piston 12 from above equals the pressure on the membrane 1 from the bottom. After that, valve 4 closes the access of compressed air from port V to port IV. Thus, the follow-up action is carried out in this version of the device operation. When the compressed air pressure drops at port I and under the membrane, the lower piston 13, together with the middle piston 12, moves downward. Valve 4 breaks off from the seat in the upper small piston 10 and communicates outlet IV with atmospheric outlet VI through the holes in valve 4 and piston 13.

With the simultaneous supply of compressed air to ports I and III, the large and small upper pistons 10 and 6 simultaneously move downward, and the lower piston 13 with the middle piston 12 upward. Filling the trailer brake control line through port IV and discharging compressed air from it is the same as described above.

When the compressed air is released from port II (when braking with the spare or parking brake system of the tractor), the pressure above the diaphragm drops. Under the action of compressed air from below, the middle piston 12 together with the lower piston 13 move upward. Filling the trailer brake control line through port IV and braking occurs in the same way as when compressed air is supplied to port I. Follow-up action in this case is achieved by balancing the compressed air pressure on the middle piston 12 and the sum of the pressure on top of the middle piston 12 and membrane 1.

When compressed air is supplied to port III (or with simultaneous air supply to ports III and I), the pressure in port IV, connected to the trailer brake control line, exceeds the pressure applied to port III. This ensures the anticipatory action of the braking system of the trailer (semitrailer). The maximum overpressure at port IV is 98.1 kPa, the minimum is about 19.5 kPa, and the nominal is 68.8 kPa. The regulation of the overpressure value is carried out by screws 8: when the screw is screwed in, it increases, when it is turned out, it decreases.

Major malfunctions

Maintenance

With TO-1 adjust the stroke of the brake chamber rods using a Key 10 * 12, a ruler. The stroke of the rods should be no more than 40 mm.

When TO- 2 Check:

The performance of the brake system with pressure gauges according to test leads at the stand.

– control lamps on the instrument panel should go out at a pressure of 4.5 ... 5.5 kgf / cm²;

The pressure regulator should operate at a pressure of 6.2 ... 7.5 kgf / cm²;

When you press the brake pedal, the pressure should drop by no more than 0.5 kgf / cm².

Splinting the pins of the brake chamber rods. The absence of cotter pins is not allowed.

Secure the brake chambers and brake chamber brackets. The tightening torque of the front brake chambers mounting nuts is 14 ... 16kgf۰m; the tightening torque of the nuts for securing the rear brake chambers is 18 ... 22kgf۰m; the tightening torque of the nuts of the bolts of the brackets is 7.5 ... 10 kgf۰m.

Maintenance consists of inspecting, cleaning the mechanisms and checking the fasteners, as well as adjusting the clearances between the pads and the drum. When inspecting the brakes, check the following.

1. Reliability of fastening the support to the flanges of the axles.

2. Tightening the nuts of the axles of the shoes and the nuts of the bolts of the brackets of the expander knuckles.

3. Condition of friction linings. If the distance from the lining surface to the rivet heads is less than 0.5 mm, then the brake linings must be replaced. It is necessary to protect the linings from oil ingress on them, as the frictional properties of oiled linings cannot be completely restored by cleaning and rinsing. If you need to replace one of the left or right brake linings, you need to change everything for both brakes (left and right wheels). After installing new friction linings, the pad must be bored out. The radius of willow stands 200_0.4 mm is given for a new drum.

After the boring of the drum during repair, the radius of the block should be equal to the radius of the bored drum. Drums can be bored to a diameter of no more than 406 mm.

4. Rotation of the expander shaft. The shaft must rotate freely in the bracket without jamming. Otherwise, the bearing surfaces of the shaft and bracket must be cleaned and then lubricated with a thin layer of grease.

Brake adjustment can be full or partial. In both cases, it is necessary to check if the wheel bearings are correctly tightened.

Brake drums must be cold. The parking brake must be released.

Full adjustment is carried out only after disassembling and repairing the brakes or in case of a violation of the centering of the working surfaces of the friction linings and the brake drum.

The necessary operations must be performed in the following sequence.

1. Loosen the nuts securing the axles of the pads and bring the eccentrics together by turning the axles with marks to one another. Marks are placed on the outer ends of the axles protruding above the nuts. Loosen the expander bracket mounting bolts.

2. Supply compressed air to the brake chamber under a pressure of 1-1.5 kgf / cm2 (press the brake pedal if there is air in the system or use compressed air from a garage installation).

In the absence of compressed air, remove the pin of the brake chamber and, pressing the adjusting lever towards the stroke of the brake chamber during braking, press the pads against the brake drum.

Turning the eccentrics to one side or the other, center the pads relative to the drum and achieve a snug fit to the drum. After that, through the windows in the brake flap, located at a distance of 20-30 mm from the outer ends of the pads, direct a 0.1 mm thick probe under the pad: it should not run along its entire width.

3. Without stopping the supply of compressed air to the brake chamber, and in the absence of compressed air - without releasing the adjusting lever and keeping the pads axles from turning, securely tighten the axle nuts and nuts of the bolts securing the expander bracket to the brake caliper.

4. Stop the compressed air supply, and if there is no compressed air, release the adjusting levers and attach the brake chamber rod.

5. Turn the worm axles of the adjusting lever so that the brake chamber stroke is within 20-30 mm.

Make sure that when turning the air supply on and off, the brake chamber rods move quickly without jamming.

6. Check how the drums rotate: they should rotate freely and evenly, without touching the pads.

After the specified adjustment, the following gaps can exist between the brake drum and the pads: at the expander knuckle 0.4 mm, at the axles of the pads 0.2 mm.

Partial adjustment is carried out only to reduce the gap between the pads and the drum, which increases during operation due to wear of the linings. The presence of large gaps, at which partial adjustment is required, is detected by an increase in the stroke of the brake chamber rods (the stroke of the rod should not exceed 40 mm). Partial adjustment is performed only by rotating the worm shafts of the adjusting levers in the same way as with full adjustment (see items 5 and 6). In this case, do not loosen the pad axle nuts and change the installation of the axles, as this can disrupt the normal adhesion of the pads to the drum during braking. If the axle setting is changed, a complete adjustment must be made.

In case of partial adjustment, the smallest stroke of the rods of the brake chambers must be set equal to 20 mm.

To obtain the same braking efficiency of the right and left wheels, it is necessary that the strokes of the rods of the right and left chambers of each axle differ little from one another.

When checking the brakes on a roller stand, it is necessary that the difference in the braking forces of the right and left wheels of the test axle does not exceed 15% of the maximum value.

Pneumatic drive. The reliability of the pneumatic drive of the car brakes depends on the correct handling and care of the brake system devices.

1. When servicing the pneumatic drive of a car, first of all, you need to make sure that the system as a whole and its individual elements are tight. Check the tightness of the pipe connections and flexible hoses especially carefully, since these are the places where compressed air leaks most often occur. Large air leaks can be detected by ear and small leaks with a soapy emulsion. Eliminate air leakage from pipeline connections by tightening or replacing individual connection elements.

The tightness of the pneumatic system should be checked at the rated pressure, with the compressed air consumers turned off and the compressor not running.

The air pressure in the air cylinders should decrease by no more than 0.15 kgf / cm2 in 15 minutes with a free position of the brake actuator controls (pedals and handles of brake valves, buttons for emergency release valves and an auxiliary brake actuator) and by 0.3 kgf / cm2 after switching on the controls.

2. To ensure the normal operation of the pneumatic drive, it is necessary to constantly drain the condensate from the air cylinders through its drain valves. The accumulation of a large amount of condensate in the cylinders is not allowed, as this can lead to its ingress into the drive devices and their failure.

If the ambient humidity is high, the condensate should be drained daily. A large amount of oil in the condensate indicates a compressor malfunction. In winter and in the case of a garage-free parking of cars, it is necessary to drain the condensate from the air cylinders more often to prevent it from freezing in the devices and pipelines. In case of freezing of condensate, it is forbidden to heat devices, pipelines and air cylinders with open fire. Hot water should be used for this purpose.

After completely draining the condensate from the air cylinders, it is recommended to fill the system with air, bringing its pressure to the nominal, and only then stop the engine.

3. Devices of the pneumatic brake drive (other than those indicated below) do not need special maintenance and adjustment. In the event of a malfunction, disassembly of these devices and elimination of their defects can only be carried out by qualified specialists.

Auxiliary brake. Servicing the auxiliary brake consists in periodically checking its attachment and rotation of the damper.

If the damper rotates tightly due to coke deposition on its axis, remove the housing with the damper, clean, rinse in kerosene, blow with compressed air and reinstall.

Compressor. When servicing the compressor, it is necessary to check the tightening of the nuts of its fastening to the engine, the tightening of the nuts of the studs securing the head, and other fasteners. The nuts of the studs securing the head will come off to tighten evenly, in two steps. The final tightening torque should be within 1.2-1.7 kgf-cm2.

After 80,000-100,000 km of run during seasonal service (in spring), the compressor head must be removed to drain the pistons, valves and seats. Valves that do not ensure tightness must be rubbed onto the seats, and heavily worn or damaged ones must be replaced with new ones. The 1st valves should also be rubbed onto the seats (until a continuous ring contact is obtained when checking for paint).

Signs of a compressor malfunction are the appearance of noise and knocking during its operation, an increased amount of oil in the condensate drained from the air cylinders. The latter is usually the result of wear on the piston rings, the oil seal at the rear end of the crankshaft or the bearings of the lower connecting rod ends.

Frost protection. At an ambient temperature of 5 ° C and higher, the fuse must be turned off. At temperatures below 5 ° C, it must be filled with ethyl alcohol.

To fill in the alcohol and control its level, the fuse handle must be lowered to the lower position and locked by turning it 90 °. Then you need to unscrew the plug with the dipstick and pour alcohol into the fuse through a funnel. After that, close the filler hole and, turning the handle 90 °, raise it to the working position.

The liquid level should be checked daily using a dipstick. Before the start of frost (with seasonal service), the internal cavities of the evaporator are cleaned and washed.

Brake valve. Maintenance of a two-section brake valve consists in its periodic inspection, cleaning from dirt, checking for leaks and working.

Is it necessary to monitor the condition of the protective rubber boot of the crane and its tightness to the body? since when dirt gets on the lever system and rubbing surfaces, the brake valve fails.

The tightness of the brake valve is checked using a soap emulsion in two positions: in the braked and unbraked positions. Air leakage through the atmospheric outlet of the brake valve at these positions1 indicates that in one of the sections there was either a steam leak in the intake valve, or the exhaust valve was out of order. A crane with such defects must be replaced.

The brake valve is fully triggered with a lever force of 80 kgf and a lever travel of 26 mm. The initial insensitivity of the crane is about 15 kgf. The pressure difference in the valve sections can be up to 25 kgf / cm2.

The service of the brake valve drive concludes! in the periodic inspection, cleaning and lubrication of the pivot joints. Check the condition of the protective cover (it should not have any breaks) and make sure that it fits snugly against the brake valve body around the entire perimeter.

It is necessary to monitor the condition of the bracket, as well as the rods and levers connecting the brake pedal with the brake valve, periodically clean them from dirt and foreign objects (branches, wire, etc.).

Fully depressed brake pedal should not bring to the floor by 10-30 mm. Its full stroke should be within 100-130 mm, and its free stroke should be 20-30 m.

If necessary, adjust the brake pedal travel by changing the length of the rod connecting the pedal with the first intermediate drive lever using the adjusting fork.

If for some reason the brake valve drive was disassembled, then during assembly it is necessary to achieve alignment of the lower hole of the intermediate lever with the cab tilt axis. Then, changing the length of the rod going from the pedal to the front lever, set the pedal to the required position in relation to the cab floor.

Brake force regulator. Maintenance of the brake force regulator consists in inspecting its attachment, in checking the condition of the elastic element and regulator levers, in cleaning from dirt and foreign objects. ... This operation must be performed by a qualified technician.

Brake chambers . Maintenance of brake chambers consists in checking their attachment to the bracket and tightness. To check the tightness, press the brake pedal, fill the chambers with compressed air, cover the clamping clamp, the hole in the body and the place where the pipeline is connected in the chamber with soap emulsion. Leakage is detected by the formation of soap bubbles. It is eliminated by tightening the clamp bolts. If the leakage is not eliminated by tightening the bolts, the camera diaphragm must be changed. The service life of the diaphragm of the brake chambers is 2 years, after this period the diaphragm must be replaced.

Spring loaded cylinders. Maintenance of cylinders with spring-loaded accumulators consists in periodic inspection and cleaning of dirt, as well as in checking their tightness and operation.

Check the tightness of these chambers when there is compressed air in the circuits of the parking brake drives and the service brake of the rear truck. In this case, it is necessary to turn off the parking brake - the cylinders of the brake accumulators are filled with compressed air.

If air leaks out through the drain hole or from under the screw of the mechanical release device, then the piston seal of the brake accumulator is faulty, and if through the inlet of the diaphragm brake chamber - the lower seal of the pusher.

Air leakage from under the cylinder mounting flange should be eliminated by tightening the bolt connections. If this technique fails to eliminate the malfunction, then the brake chambers should be replaced.

To check the tightness of the diaphragm brake chambers, press the service brake pedal. If air escapes through the inlet fitting of the brake cylinder, the lower pusher seal is faulty.

When air escapes from under the clamp, tap it with a hammer and tighten the clamp fastening bolts. If the leak is not eliminated, the diaphragm should be changed.

The diaphragm should also be replaced if air leaks through the holes in the camera body. The service life of the diaphragm is 2 years; after expiration, the diaphragm should be replaced.

Only a qualified mechanic should disassemble, inspect, clean and lubricate parts of a spring-loaded cylinder in a workshop using a special device and observing safety measures.

Connecting heads. Maintenance of the coupling heads consists in periodic inspection, cleaning from dirt and checking the tightness of the connection between the heads of the car and the trailer.

The tightness test should be carried out when the vehicle is coupled to the trailer, sequentially in the braked and unbraked positions.

Do not drive vehicles with leaking brake line connections.

To eliminate leaks in the connection heads, it is necessary to replace the O-rings or the complete connection heads.

When operating a car without a trailer, it is necessary to close the connecting heads with covers that protect them from dirt, snow, moisture.

Checking the operability of the pneumatic brake drive consists in determining the output parameters of the air pressure along the circuits using control pressure gauges and standard instruments located in the driver's cab (two-pointer pressure gauge and a block of brake system warning lamps). Control pressure gauges are installed on the control output valves available in all circuits of the pneumatic drive, and on the connection heads of the “Palm” type of the supply (emergency) and brake lines of the two-wire drive and type A of the connecting line of the single-wire drive of the trailer brakes.

Control outlet valves are mounted:

on the pressure limiting valve - the front axle wheel brake drive circuit;

on the left side member of the frame in the area of ​​the rear axle - the circuit of the drive of the brake mechanisms of the wheels of the middle and rear axles;

on the right side member of the frame in the area of ​​the rear axle and in the air tank - the drive circuit of the parking and spare brakes mechanisms;

in the air cylinder - the circuit for the drive of the auxiliary brake mechanism and the supply of compressed air consumers.

Before checking the functionality of the pneumatic brake drive, the compressed air leaks from the pneumatic system must be eliminated.

Check sequence. 1. After starting the engine, fill the neumatic system with air (until the pressure regulator 12 is triggered). In this case, the pressure in all circuits of the brake drive and the connecting head 35 (type "Palm") of the supply line of the two-wire drive of the trailer brakes should be in the range of 6.2-7.5 kgf / cm2, and in the connecting head 36 (type A) of the single-wire drive 4.8-5.3 kgf / cm2. The warning lamps of the brake system warning lamp unit should go out when the pressure in the circuits reaches 4.5-5.5 kgf / cm2. At the same time, the noise signaling device (buzzer) stops working.

2. Depress the service brake pedal fully. The pressure on a two-pointer pressure gauge 5 in the driver's cab should drop sharply, but not more than by 0.5 kgf / cm2. In this case, the pressure in the control valve of the control outlet of the brake mechanism drive circuit of the wheels of the front axle should be equal to the indication of the upper scale of the two-pointer pressure gauge in the driver's cab. The pressure in the control valve of the control outlet of the brake mechanism drive circuit of the wheels of the middle and rear axles must be at least 2.5 kgf / cm2 (for an unloaded vehicle). Lift up the vertical rod of the drive of the brake force regulator 30 by the amount of suspension deflection under load (40 mm for cars model 5320) The pressure in the brake chambers 27 should be equal to the indication of the lower scale of the two-pointer pressure gauge, and in the connecting head 35 of the brake line of the two-wire drive 6.2 -7.5 kgf / cm2; in the connecting head 36 of the connecting line - fall to 0.

3. Set the handle of the parking brake valve to the front fixed position. The pressure in the control valve of the control outlet of the circuit of the drive of the mechanisms of the parking and spare brakes must be equal to the pressure in the air cylinder 24 of the parking and spare circuit and be in the range of 6.2-7.5 kgf / cm2, the pressure in the connecting head 35 of the brake line of the two-wire drive - equal 0, in the connecting head 36 - from 4.8 to 5.3 kgf / cm2.

4. Set the parking brake valve drive handle 7 to the rear fixed position. The parking brake warning lamp should be on (flashing) on ​​the brake warning lamp block. The pressure in the valve of the control output of the circuit of the drive of the mechanisms of the parking and spare brakes and in the connecting head 36 should drop to 0, and in the connecting head 35 of the brake line of the two-wire drive should be equal to 6.2-7.5 kgf / cm2.

5. With the handle of the parking brake valve in the rear fixed position, press the button of the emergency release valve 6. The pressure in the control valve of the control outlet of the drive circuit of the parking and spare brakes must be equal to the indication of the two-pointer pressure gauge 5 in the driver's cab. The rods of the brake chambers 26 of the middle and rear axle mechanisms must be retracted.

6. Release the emergency release valve button The pressure in the control valve of the parking and spare brake mechanisms should drop to 0.

7. Press the auxiliary brake valve 8. The rods of the pneumatic cylinders for controlling the engine brake flaps 18 and for turning off the fuel supply // should extend. The air pressure in the brake chambers of the trailer (semi-trailer) must be equal to 0.6 kgf / cm2.

Repair of brake mechanisms

At overhaul the brake mechanism is replaced with new ones:

Expanding knuckle rubber O-rings in the bracket; after replacing them, the sealing lips of the ring must not have any damage;

Expanding knuckle bushings, press-in force of the bushings must be at least 6000 N; after replacement, the bushings are bored to a diameter of 38.0-38.027 mm;

Friction brake linings of brake pads.

New friction linings are riveted to the brake pads using a special press adapted for riveting brake linings. The riveting of the linings to the block must be made in such a way that there is no gap between the linings and the block in the area of ​​the rivets. Brake pads with lining assemblies are machined (turned) to the diameter of the bored brake drum on the machine. The radius of the pads with friction linings should be 199.6-200 mm.

Routing

TO-2 of the KAMAZ 5320 car.

Performers 1 person

Labor intensity 0.5 people. \ hour.

The specialty and rank of each worker is a repairman car III discharge

Safety and health during maintenance and repair of cars

Basic concepts in the field of labor safety. Labor protection is understood as a system of legislative acts and the corresponding measures aimed at preserving the health and working capacity of workers. The system of organizational and technical measures and means to prevent industrial injuries is called safety engineering.

Industrial sanitation provides for measures for the correct arrangement and maintenance of industrial enterprises and equipment in a sanitary respect (reliable ventilation, proper lighting, correct arrangement of equipment, etc.)

Industrial hygiene aims to create the healthiest and most hygienically favorable working conditions, preventing occupational diseases of workers.

The order of the briefing. At motor transport enterprises, the organization of work on safety and industrial sanitation is entrusted to the chief engineer. In workshops and at production sites, the responsibility for labor safety is borne by the heads of workshops and foremen. The implementation of safety measures and industrial sanitation is supervised by a senior safety engineer (engineer) and trade union organizations. The instructions of the senior engineer (engineer) on safety measures can only be canceled by the head of the enterprise or Chief Engineer.

One of the main measures to ensure labor safety is the mandatory briefing of newly hired and periodic briefing of all employees of the enterprise. The briefing is carried out by the chief engineer of the enterprise or a senior engineer (engineer) for safety measures. Newly recruited people are introduced to the main provisions on labor protection, internal regulations, fire safety requirements, the specifics of the work of the enterprise, the duties of employees to comply with the rules of labor safety and industrial sanitation, the procedure for moving around the territory of the enterprise, protective equipment for workers and methods of providing first aid to victims ... Of particular importance is on-the-job instruction showing safe work practices.

All employees, regardless of their work experience and qualifications, must undergo re-training once every 6 months, and persons performing high-risk work (welders, vulcanizers, etc.), once every 3 months. When re-instructing, the violations are analyzed in detail. Each briefing is recorded in a journal.

SAFETY REQUIREMENTS FOR ELIMINATION OF FAILURES AND MALFUNCTIONS OF THE VEHICLE ON THE LINE

If any malfunctions are found during work on the line that require immediate elimination, the driver is obliged to put the car on the side of the road and carefully inspect it.

Troubleshooting can be started if the necessary equipment and tools are available and if the amount of repair can be done on the line.

Loaders, passengers and other persons who do not have the right to do so must not be allowed to repair cars.

During repairs, the driver must strictly follow the safety rules. In order for the car to remain stationary, it must be braked with the parking brake and engaged in first gear, and when working on steep slopes, place at least two stops (shoes) under the wheels of the car. When lifting the car, the jack must be installed vertically, and a wooden board must be placed under its base, but in no case stones and bricks. When carrying out work related to the removal of wheels, it is imperative to substitute a tragus under the raised vehicle.

If the driver is not able to eliminate the malfunctions in the car himself, he is obliged to inform the administration of the car company about the need to call for technical assistance.

SAFETY REQUIREMENTS FOR MAINTENANCE AND REPAIR OF A VEHICLE AT A MOTOR TRANSPORTATION COMPANY

Safety requirements. When servicing and repairing vehicles, it is necessary to take measures against their independent movement. Maintenance and repair of a car with a running engine is prohibited, except in cases of its regulation.

Lifting and transporting equipment must be in good condition and used only for its intended purpose. Only trained and instructed persons are allowed to operate this equipment.

When working, do not leave tools at the edge of the inspection ditch, on the steps, hood or fenders of the vehicle. During assembly work, it is forbidden to check the coincidence of the holes in the parts to be joined with your fingers: for this, you must use special crowbars, barbs or mounting hooks.

During disassembly and assembly of units and assemblies, special pullers and keys should be used. Hard-to-remove nuts must first be moistened with kerosene and then unscrewed with a wrench. It is not permitted to loosen the nuts with a chisel and hammer.

It is forbidden to obstruct the passages between workplaces with parts and assemblies, as well as accumulate a large number of parts at the disassembly points.

The operations of removing and installing the springs pose an increased danger, since they have accumulated significant energy.

These operations must be performed on stands or using devices that ensure safe work.

Hydraulic and pneumatic devices must be equipped with safety and relief valves. The working tool should be kept in good condition.

Industrial sanitation and industrial hygiene requirements. Rooms in which workers, when performing maintenance or repairs on a car, must stay under it, must be equipped with inspection ditches, ramps with guiding safety flanges or lifts.

Supply and exhaust ventilation must ensure the removal of emitted vapors and gases and the supply of fresh air. Natural and artificial lighting of workplaces must be sufficient for the safe performance of work.

On the territory of the enterprise, it is necessary to have sanitary facilities - dressing rooms, showers, washrooms (those working with leaded gasoline must be provided with hot water).

FIRE-FIGHTING MEASURES AT MOTOR TRANSPORTATION PLANTS

The main causes of fires at motor transport enterprises are the following: malfunction of heating devices, electrical equipment and lighting, their improper operation; spontaneous combustion of fuels and lubricants and cleaning materials if stored improperly; careless handling of fire.

In all production areas, the following fire safety requirements must be met: smoke only in specially designated areas; do not use open fire; store fuel and kerosene in quantities not exceeding the replacement requirement; do not store empty fuel containers and lubricants; carry out a thorough cleaning at the end of each shift; clean up spilled oil and fuel with sand; collect used cleaning materials, put them in metal boxes with lids and, at the end of the shift, take them out to a specially designated place.

Any fire that is noticed in a timely manner and has not received significant spread can be quickly extinguished. The success of extinguishing a fire depends on the speed of notification of its beginning and its implementation. effective means fire extinguishing.

A telephone and a fire alarm are used to alert about a fire. In the event of a fire, you must immediately report it by phone 01. There are two types of fire alarms - electric and automatic. The receiving station of electrical signaling is installed in the fire department, and the detectors are installed in production facilities and on the territory of the enterprise. The fire signal is given by pressing the detector button. In automatic fire alarms, thermostats are used, which, when the temperature rises to a predetermined limit, turn on the detectors.

Water is the most effective and most common extinguishing agent for fires, but in some cases it cannot be used. Flammable liquids that are lighter than water cannot be extinguished with water. For example, gasoline, kerosene, floating on the surface of the water, continue to burn. Acetylene and methane react with water to form flammable and explosive gases. If it is impossible to extinguish with water, the burning surface is covered with sand, covered with special asbestos blankets, foam or carbon dioxide fire extinguishers are used.

In especially fire-hazardous industries, stationary automatic installations of various designs, operating at a given temperature and supplying water, foam or special fire-extinguishing compositions.

ELECTRICAL MEASURES FOR MAINTENANCE AND REPAIR OF VEHICLES

The danger of electric shock arises when using faulty hand-held electrified tools, when working with faulty switches and fuses, when in contact with air and wall electrical wiring, as well as accidentally energized metal structures.

Electrified tools (drills, wrenches, grinders, etc.) are connected to a 220V network. it is allowed to work only with tools that have protective earthing. Plug connections for turning on the tool must have a grounding contact that is longer than the working contacts and differs from them in shape. When the instrument is plugged into the mains, the grounding contact enters the connection to the mains socket first, and when switched off it comes out last.

When moving with an electrified tool from one place of work to another, do not pull on the wire. Do not run the wire through walkways, driveways and parts storage areas. Do not hold an electrified tool with one hand on the wire.

It is possible to work with an electrified tool with an operating voltage exceeding 42 V only with rubber gloves and galoshes or standing on an insulated surface (rubber mat, dry wooden shield).

To avoid electric shock, use portable light bulbs with safety nets. In a room without increased danger (dry, with non-conductive floors), portable lamps with a voltage of up to 42 V can be used, and in especially hazardous rooms (damp, with conductive floors or conductive dust), the voltage should not exceed 12 V.

Bibliography

1. Automobiles KAMAZ. Models with wheel arrangement 6x4 and 6x6. Operation, repair and maintenance manual. M., 2004.314 p.

2. Guidelines for the repair and maintenance of KamAZ vehicles. M., 2001, 289 p.

3. Parchment L.R. The driver of the KamAZ car. M., 1982.160 p.

4. STP SGUPS 01.01–2000. Course and diploma projects. Requirements for registration. Novosibirsk, 2000.44 p.

TECHNICAL OPERATION

TRANSPORTATION AND TRANSPORTATION TECHNOLOGY MACHINES AND

TRANSPORTATION EQUIPMENT

Laboratory workshop

Samara State Technical University

Published by the decision of the RIO SamSTU

UDC 656.1 (088.0)

V. V. Saveliev

T 38 Technical operation transport, transport and technological machines and transport equipment: laboratory workshop / V.V. Saveliev... - Samara: Samar. state tech. un-t, 2013 .-- 65 p.

The laboratory workshop is intended for students and bachelors of specialties 190603 and 190600 to study the disciplines "Systems, technologies and organization of services at car service enterprises" and "Technical operation of transport, transport-technological machines and transport equipment".

The technologies of technical maintenance No. 1 and 2 of KamAZ-5320 vehicles, as well as maintenance of gas-cylinder vehicles are presented. The technique of standardization of fuel consumption of the rolling stock of motor transport is considered.

UDC 656.1 (088.0)

ISBN 978- © V.V. Savelyev, 2013

© Samara State

Technical University, 2013

INTRODUCTION

The high-quality work of transport depends on the technical condition of the rolling stock. The solution to this problem, on the one hand, is provided by the automotive industry through the creation and production of vehicles with high operational reliability and manufacturability, on the other hand, by improving the methods of technical operation of vehicles.

Optimal control of the technical condition of vehicles can be organized only when a clear relationship is ensured between all the main structural elements of the model. For the organization of management, first of all, information is needed in the broadest sense, based on diagnostics, which provides a complete picture of the state of the object. Based on this information and the efficiency criterion (maintenance and repair costs), a decision is made according to which the management should be organized.

Maintenance management is also possible on the basis of the optimal organization of maintenance and repair of vehicles. At the same time, a systematic approach is ensured by the fact that the forms and methods of organizing maintenance and repair are considered in conjunction with control actions - types of maintenance and repair.

Maintenance and repair of cars according to the technical condition, as well as the traditional method of maintenance and repair according to operating time, by their nature are also scheduled preventive (the scope of work on technical diagnostics and the frequency of their implementation are planned). Constant monitoring during the operation of vehicles for their level of reliability and the technical state of functional systems and vehicle elements in order to timely identify the pre-failure state of the latter with the subsequent replacement or restoration of the values ​​of the monitored parameters to the specified values ​​provides a preventive nature.

The use of new methods of maintenance and repair is based on a deep knowledge of the reliability characteristics of functional systems and elements, a clear organization of information support, and the widespread use of diagnostic equipment, high level operational manufacturability of automotive technology. A significant restructuring of the technology and organization of the repair and maintenance production of the ATP is required. First of all, it is necessary to create modern technical diagnostics and information support services on them.

The most important condition for ensuring a high level of technical condition of vehicles is the development of PTB of motor transport enterprises on the basis of reconstruction and technical re-equipment.

The development and implementation of new methods of maintenance and repair of cars is impossible without training and retraining of a wide range of performers of work on the technical training of automotive equipment.

Laboratory work No. 1

Maintenance technology of the KAMAZ-5320 vehicle

purpose of work- to study an approximate list of maintenance operations, the equipment used, the standard values ​​of the adjusting parameters of the elements of cars and get practical skills for carrying out control and fastening, adjusting and lubrication work during maintenance of the KamAZ-5320 vehicle.

General information and basic concepts. Road transport is a source of increased danger and environmental pollution. V Russian Federation per last years on average, about 200 thousand road accidents occur, 12-15% of which are due to technical failures.

The share of road transport accounts for over 50% of emissions of toxic compounds into the atmosphere. At the same time, the amount of toxic components contained in the exhaust gases is mainly determined by the level of maintenance of the power supply systems, ignition and engine gas distribution mechanism, which ensure the completeness of fuel combustion.

The total cost of maintaining vehicles in good technical condition is 15-25% of the cost of transportation. These costs largely depend on the ability to determine the actual need of vehicles for preventive and repair actions; implementation of the recommendations of the planned preventive maintenance and repair system; introduction of modern, scientifically grounded technological processes of maintenance and
repair.

Research and experience of leading motor transport enterprises (ATP) show that carrying out maintenance in full using advanced technologies significantly improves the quality and culture of workers' work, reduces the number of sudden failures and costs for TR by 8-12%, and reduces the consumption of fuel and lubricants. by 7-10%, increase the technical readiness factor by 3-5% and tire mileage up to 5-7%.

The current preventive maintenance and repair system of the rolling stock of road transport provides for the implementation of a specific list of maintenance operations with a given labor input after certain runs. Thus, maintenance is a preventive measure.

The purpose of maintenance is to ensure traffic safety, prevent possible failures and malfunctions, as well as reduce the wear rate of mechanisms, systems and vehicle units during operation.

The technical maintenance process is a given sequence of operations performed on the elements of the vehicle in order to improve its technical condition. As a rule, maintenance operations are grouped according to the type of specialization of work when they are performed, which are reflected in the technological maps of work posts for performers. The generally accepted typical technology of vehicle maintenance provides for the following procedure: first, cleaning and washing work is performed, then control and diagnostic, fastening, adjusting and lubrication.

According to the frequency, the list of operations and the complexity of the work performed, the types of maintenance are distinguished: daily maintenance (EO), the first (TO-1), the second (TO-2) and seasonal (STO).

Daily maintenance is performed after returning and before leaving the rolling stock line. With EO, they carry out general control of systems and mechanisms that ensure the safety of vehicle movement, cleaning and washing, refueling with fuel, oil and coolant.

Types of TO-l and TO-2 differ in frequency, scope of work and labor intensity. At TO-l work are carried out without disassembling the vehicle units. With TO-2, partial disassembly of some elements of the car is allowed in order to perform adjustment and lubrication work.

Seasonal maintenance, as a rule, is performed twice a year in order to prepare the car for autumn-winter and spring-summer operation and is combined with the next technical impact (according to the schedule) TO-2.

The regulatory document on the basis of which the planning and organization of maintenance and repairs are made is the Regulation on the maintenance and repair of the rolling stock of road transport (hereinafter referred to as the Regulation), which is periodically reviewed and amended. Car manufacturers, within the framework of the general preventive strategy described in the Regulation, concretize the standards of technical operation in relation to individual basic models and their modifications. These standards are reflected in the operating manuals of specific families of cars produced or in their service books.

In the initial period of vehicle operation, when the mates of the main elements of the internal combustion engine (ICE), transmission and chassis are running-in, in addition to EO, additional types of maintenance TO-1000 and TO-4000 are introduced. The first of them is performed in the interval of the first 500 - 1500 km of the vehicle's run, the second - after 3000 - 4000 km.

In the post-break-in, the so-called main period of operation, for modern domestic cars the normative frequency of TO-l is assigned within 4000 - 5000 km, TO-2 - 15000 - 20,000 km. The indicated values ​​of the frequency of TO-1 and TO-2 are given for category 1 of operation and are adjusted depending on the actual operating conditions of vehicles.

Maintenance for KAMAZ vehicles is carried out according to the EO scheme - TO-I000 (service A) - TO-4000 (service B) - TO-1 (service 1 - after 4000 km) - TO-2 (service 2 - after 16000 km) - Service station (service C - twice a year).

This methodological guide is aimed at studying the general strategy of technological processes for the implementation of preventive maintenance work on vehicles. As a result of this laboratory work, the student must:

Have an idea of ​​the general structure and principle of operation of the equipment used in the maintenance operations of the car;

Know the standards and diagnostic parameters of the technical condition of the elements of the car and general information about the technology of carrying out all types of maintenance on the example of domestic cars;

To be able to perform maintenance work on the main units, mechanisms and systems of the vehicle.

Task 1. Study the daily maintenance of the car.

Daily maintenance, with the exception of car washing, is carried out by the driver. The general technical condition of the vehicle within the EO is monitored by the duty mechanic when the vehicle is released onto the line.

When preparing a car for departure, you must:

Check the level and, if necessary, add oil to the engine crankcase and coolant to the radiator;

Make sure that there are no leaks of fuel, grease, coolant and brake fluid in pipelines and connections;

Wipe off the radiator grille, headlights, sidelights, rear lights, cockpit glass, license plates;

Make sure that the working and parking brakes and steering systems are in good working order. If there is no air in the hydraulic drive, the brake pedal should not pass more than 1/2 of the working stroke. The parking (hand) brake is checked by trial tightening of the lever, which should move by 4 - 6 fixing clicks. The technical condition of the steering is assessed using the K-187 (K-402) device or visually by the free play (play) of the steering wheel with straight front wheels. Total backlash in steering in the absence of these limit values ​​established by the manufacturer of the car, according to GOST R 51709 - 2001 “Motor vehicles. Safety requirements for the technical condition and test methods should not exceed 10 0 for cars and trucks and buses created on the basis of their units, 20 0 - for buses and 25 0 - for trucks with a given standard effort on the steering wheel;

Start the engine and check the controls
his work. Signal lamps - indicators of low oil pressure in the main line of the lubrication system two (the minimum allowable oil pressure for gasoline two is 0.05 and 0.1 MPa for diesel engines) and malfunctioning generator (charging the storage battery (battery "- should go out. The car is not allowed to operate if, when the ignition is turned on, the indicator for monitoring the elements of brake systems, emergency drop in the level of brake fluid, and the value of the air pressure in the reservoirs of the pneumatic brake system on the pressure gauge is lower than the standard value. attention to the amount of fuel in the tank and the operation of lighting and signaling devices.

The instruction to the duty mechanic of the ATP for checking the technical condition of cars when they are released to the line provides for a prohibition on leaving the vehicle if the following is detected malfunctions or violations of regulatory documents.

In appearance and configuration:

Vehicle the condition of the external and internal parts of the car (bus) body does not meet the cleanliness requirements;

Damaged or missing license plates, wheel-mounted mud guards, side and central rear-view mirrors, sun visors, fire extinguishers, first-aid kit, emergency stop sign;

The locks of the doors of the passenger compartment or the driver's cab are faulty;

There are cracks in the windshields in the area where the wiper is cleaning half of the glass on the driver's side.

Steering:

The play of the steering wheel exceeds the standard value or the rotation of the steering wheel is difficult, there is damage to the steering column;

The tightness of the crankcase of the steering mechanism or the pneumatic-hydraulic system of the power steering is broken;

Damaged or loose attachment of the crankcase to the steering column;

Pivot joints of the steering drive are damaged, not secured or have increased play.

On the brake control system:

With the engine running, when the brake pedal is pressed once with a force of 686 N (70 kgf), the gap between the pedal and the cab floor is less than 25 mm;

The tightness of the pneumatic or hydraulic drive... Permissible air pressure drop in the brake drive system at idle engine: with a free position of the brake system control - no more than 0.05 MPa (0.5 kg / cm 2) in 30 minutes;
when the brake system is activated - 15 min. Air leaks from the wheel working brake chambers are not allowed;

When the ignition is turned on, the indicator for monitoring the elements of brake systems, emergency drop in the level of the brake fluid comes on;

The braking efficiency of the vehicle is not ensured to the requirements of GOST R 51709 - 2001. During a road test on a flat, dry asphalt concrete surface in straight-line motion with an initial braking speed of 40 km / h by pressing the service brake pedal once with a force of 686 N (70 kgf), the braking distance trucks of categories Nl, N2, N3, passenger and utility vehicles of categories M2 and M3 exceeds 17.7 m
over the standard traffic corridor with a width of 3 m for passenger cars of categories Ml with a pedal force of 490 N (50 kgf), the braking distance should not be more than 15.8 m;

The parking brake system does not provide a stationary state of the vehicle on a supporting surface with a slope of 16%;

The brake light (brake light) does not turn on when the brake pedal is pressed;

Parking brake locking device does not work.

The force applied to the parking brake control exceeds 589 N (60 kg).

By engine and transmission elements:

The tightness of the power supply systems and the release of exhaust gases is broken;

The tightness of the lubrication systems of the internal combustion engine, gearbox, rear axle gearbox housing is broken;

The fastening of the internal combustion engine, gearbox, flanges is loosened cardan shaft, muffler elements, springs;

The clutch is not completely disengaged, it is spontaneously disengaged or the gear is engaged with difficulty;

Vibration and knocking of the propeller shaft are noticeable when shifting gears and moving the car.

On wheels and tires:

Absence or weak tightening of the nut for fastening the discs and wheel rims;

The presence of cracks and visible irregularities in the shape and size of the mounting holes on the wheel rims;

Tire tread depth truck less than 1 mm, bus - less than 2 mm, passenger cars - 1.6 mm (or the appearance of one tread wear indicator);

The presence of tire damage, exposing the cord, or local tread detachment;

The air pressure in the tire is not correct.

By external light devices:

High beam or low beam headlights do not work or are not adjusted;

Inoperative indicators of the inclusion of light devices located in the driver's cab;

The headlight switch is faulty;

The braking signal (brake light) does not work;

The direction indicator or its side repeater does not work;

The flashlight does not work reverse when engaging reverse gear;

The parking light or the state rear light does not work registration plate;

The activation of the alarm does not ensure the operation of all direction indicators and side repeaters in flashing mode;

There are fractures and cracks in the headlight lenses.

By additional equipment :

Windshield wipers or washers, speedometer, ventilation and heating systems do not work (in cold weather).

Compliance with the requirements for gas-cylinder vehicles:

When releasing a car running on liquefied petroleum or compressed natural gas, it is necessary to check the fastening of gas cylinders, the condition and tightness of the element connections. gas system nutrition.

When returning a gas vehicle to the company, check gas tightness and gasoline systems supply, close the flow valve and exhaust all gas in the system.

Driving along the ATP to the TO, TP and to the parking lot of the car should only be carried out when working on gasoline or diesel system nutrition.

Special conditions: the duty mechanic is obliged to record all cases of return of vehicles to the vehicle with external damage, to enter in the log and draw up an act for damage.

Task 2. Learn the operations of the first maintenance.

For KAMAZ vehicles, TO-l is produced after 4000 km of run (for 1 category of operation), labor input 3.6 man-hours. In an ATP with a rolling stock of more than 100 units, it is recommended that TO-l be performed at three specialized posts by the flow method.

Post 1 - control and fastening works:

Check the condition of the platform, the cab, the serviceability of the door mechanisms, the action of the wipers;

Check the fastening of the swivel arms and articulated joints of the longitudinal and transverse steering rods. Increased clearance in swivel joints The steering rods are determined visually or by touch by the relative movement of the mating parts arising from the rotation of the steering wheel in opposite directions with a force of 50 ... 60 N, which is carried out by the operator sitting in the cab. Reciprocal movements should be insignificant;

Check the tightening of the nuts of the ladders of the springs;

Tighten the nuts securing the flanges of the exhaust pipes, flange bolts cardan shafts, fastening the gearbox;

Check the fastening of the support and the tightness of the stuffing box seal of the movable spline connection;

Check the fastening of the steering box to the frame and bipod, the tightening of the wheel nuts, the condition of the tires and the air pressure in them;

Tighten the nuts securing the water pump, generator, starter, high pressure fuel pump (carburetor), throttle and air damper drives must work without jamming;

Clean the outer surface of the spark plugs and the distributor cap with a cloth soaked in clean gasoline:

Clean the ventilation holes of the battery and check the electrolyte level (10-15 mm above the separator plates);

Check the brake fluid level in the master brake cylinder and the presence of water in the reservoir of the windshield washer;

Check and, if necessary, fasten the engine to the frame.

Post 2 - adjustment work:

Check the condition and tension of the fan and alternator belts (belt deflection should be 10 - 20 mm when pressing the belt in its middle part with a thumb with a standard force of 40 - 80 N);

Check the free play of the clutch pedal with a straight edge. The increased travel of the clutch pedal can cause incomplete separation of the engine shaft from the input shaft of the gearbox, which makes it difficult to shift them and intensively wears out the clutch disc. On the contrary, a small free play does not ensure reliable engagement of the clutch, which leads to slipping of the discs and their rapid wear;

Check the technical condition of the parking and service (foot) brakes, use a ruler to determine the free and working travel of the service brake pedal. Adjust the brakes if necessary;

Check the clearances in the pivot joint steering knuckles with the NIIAT-1 device (radial clearance - no more than 0.75 mm, axial 1.5 mm) or visually, swinging the suspended wheel by hand in a vertical plane;

Check the operation of the valve mechanism by ear and, if necessary, adjust the clearances between the valves and rocker arms.

Post 3- lubrication and filling works:

Bring the oil level in the engine crankcase to normal;

Lubricate the clutch and brake pedal roller;

Lubricate the steering rod joints and steering knuckle pins through grease fittings until fresh grease appears from the connection;

Lubricate the intermediate support bearing through a grease fitting until fresh grease appears from the control hole;

Check and bring to the control plug the oil level in the drive axle housings, as well as in the gearbox housing;

Check and bring to normal the level of the brake fluid "TOM", "Dew") in the master cylinder;

Drain the fuel from the filter sump.

As a rule, in the zones TO-1 and TO-2 at specific posts, technological maps of the corresponding services are given to the performers. For TO-1 of KamAZ-5320 vehicles, the technological map is presented in Table 1.1.

Table 1.1

Technological map of operations TO-1 of the KamAZ-5320 vehicle

Task 3. Examine the operations of the second and seasonal maintenance.

Work on TO-2 is carried out at a specialized post using an inspection ditch or a hoist. In autumn and spring, TO-2 is usually combined with seasonal service, therefore, the technological map (Table 1.2) contains both types of technical actions.

Table 1.2

Technological map of operations TO-2 of the KamAZ-5320 vehicle

Note.
Checking the functionality of the pneumatic brake drive
the vehicle is produced using standard instruments in the cockpit
driver (two-pointer pressure gauge, brake plate) and
control pressure gauges for control output valves, which
installed in all brake circuits, and
connecting head type "Palm" and type "A". Valves
control terminals are located in the following locations:
- the front axle service brake drive circuit - on the valve
pressure limiter;
- the circuit of the drive of the rear bogie brakes - on the left
(in the direction of the vehicle) the frame side member in the area of ​​the rear axle;
- auxiliary and spare brakes drive circuit - on
the right side member of the frame in the area of ​​the rear axle and the air tank
contour;
- auxiliary brake drive circuit for consumers -
in the air tank of the circuit.
A functional check should be carried out after
elimination of air leaks in the pneumatic system.

Check sequence

1. Connect test pressure gauges to the valves
control output and connecting heads.
2. After starting the engine, fill the air system.
After operation of the pressure regulator, the pressure in all
brake drive circuits and supply connection head
the line of the two-wire drive must be within
0.62-0.75MPa (6.2-7.5kgf / sq. Cm) .Pressure
connecting head type "A" must be within
0.48 - 0.53 MPa (4.8-5.3 kgf / sq. Cm).
brake display should not light up.
By extinguishing the last lamp the beeping must stop
work.
3. Fully press the brake pedal.
the two-pointer fog meter in the driver's cab
decrease by no more than 0.05 MPa (0.5 kgf / sq. cm).
pressure in the control valve
brake front axle at the beginning of the pedal stroke should increase
slowly, and with fully depressed pedal, it should be equal to
pressure shown by the top scale of the two-handed
pressure gauge valve pressure
the drive of the working brakes of the middle and rear axles (when
fully applied) must be at least 0.25 MPa (2.5
kgf / sq. cm) (for an unladen vehicle).
vertical traction drive of the brake force regulator by the value
static stroke (suspension deflection 50 - 55 mm) pressure
the brake chambers of the rear carriage must be equal to the pressure
indicated by the lower scale of a two-pointer manometer.
head type "A" should drop to 0. Head pressure
Palm-type brake line of the two-wire actuator must
rise to a value of 0.62 - 0.75 MPa (6.2 - 7.5 kgf / sq. cm).
4. Hand-operated reversing lever
set the parking brake to the front fixed
Position. Pressure at test outlet.
the drive of the parking and spare brakes must be equal to
pressure in the air cylinder of the parking and spare
brakes are within 0.62 - 0.75 MPa (6.2 - 7.5
kgf / sq. cm).
Wherein:
- the pressure in the connection head type "A" must be in
within 0.48 - 0.53 MPa (4.8 - 5.2 kgf / sq. cm);
- pressure in the connecting head type "Palm" brake
the line of the two-wire drive must be 0.
5. Manual reversing crank
parking and spare brakes
fixed position.
Wherein:
- the control lamp should be on in a blinking mode;
- pressure in the control outlet valve of the drive circuit
parking and spare brakes and coupling head type
"A" should go down to 0;
- pressure in the connecting head of the type "Palm" brake
the line of the two-wire actuator must be within
0.62 - 0.75 MPa (6.2 - 7.5 kgf / sq. Cm).
6. With the position of the valve handle (reverse action with manual
control) in the rear fixed position press the button
emergency release, when the pressure in the valve
test terminal for the drive circuit of the parking and spare
brakes must be equal to the pressure shown
two-pointer pressure gauge in the driver's cab.
cameras must be removed.
Release the emergency release button. Air pressure
in the cavities of the spring accumulators should decrease to 0.
7. Press on the edge of the auxiliary brake.
pneumatic cylinders, valves, motor brakes, and
the fuel cut-off must extend, while the pressure
air in the brake chambers of the trailer (semitrailer) must be
equal to 0.06 MPa (0.6 kgf / sq. cm).
8. In the process of checking the efficiency of the pneumatic system of the lamp
the brake display should light up and should start working
pressure drop buzzer in the corresponding circuit below
0.48 - 0.52 MPa (4.8 - 5.2 kgf / sq. Cm).

Conclusion

In this term paper on the topic "Maintenance and repair of the KAMAZ 5320 brake system" all issues were considered and a plan of its content was drawn up, the necessary literature was purchased and an explanatory note was drawn up for writing the content of the plan on this topic.

Questions of purpose, device, malfunctions and their elimination are given in the descriptive part of the explanatory note. In the section on labor protection, the main provisions for performing technological operations in compliance with safety standards are given. By writing and formatting the content of the disclosure of this topic, as well as the implementation of the practical part, certain professional knowledge and skills in the specialty "auto mechanic" were shown.

In my term paper, I laid out general arrangement, purpose and principle of operation of the parking brake system KAMAZ-5320. The main types of work that are performed during repair and maintenance are considered.

Described the technical and daily maintenance of the parking brake system of the KAMAZ-5230 vehicle. Studied the main faults and how to fix them. He analyzed the operating procedure of the parking brake system, methods of repairing it and the feasibility of spending on its repair.

Thus, in my term paper, in my opinion, I was able to sufficiently succinctly present the chosen topic and strengthen my knowledge.

Bibliography

1. V.N.Barun, R.A.Azamatov and others. "KamAZ Automobiles". M.: Transport, 2009. 96s.

2. GVKramarenko "Technical operation of cars" M .: Transport, 2008. 105s.

3. EI Kogan "Labor protection at road transport enterprises" M .: Transport, 2009. 89s.

4. A.G. Puzankov "Automotive equipment and maintenance" Moscow Publishing center "Academy" .2008. 415s.

5. Babusenko S.M. Car repair. M .: Transport, 2007. 67s.

6. Shurkin VS, Ponizovkin AN Brief automobile reference book. M .: Transport, 2009. 95s.

7. Sukhanov B.N., Borzykh I.O., Bedarev Yu.F. Car maintenance and repair. Graduation Design Manual. M .: Transport, 2008. 68s.

8. Regulation on the maintenance and repair of the rolling stock of road transport. M .: Transport, 2010. 69s.

9. Drozdov N.E., Feigin L.A., Zalensky V.S. Construction machinery and equipment. Course and diploma design. M .: Stroyizdat, 2008. 115s.

1. Check the condition of the front springs, the tightening of the ladder nuts, the fastening of the clamps and the spring covers, and, if necessary, fix them.

2. Check the condition, tightness and fastening of the front shock absorbers, repair if necessary.

3. Check the condition of the rear springs, the tightening of the ladder nuts, the fastening of the clamps and the spring covers.

4. Check the condition, tightness and fastening of the rear shock absorbers, repair if necessary.

5. Check the condition and fastening of the correction springs, the tightening of the nuts of the ladders, the shackle bracket, if necessary, eliminate the malfunctions.

6. Check the condition and tightness of pipelines and devices of the pneumatic part of the brake system (pressure regulator, brake valve, air cylinders, pneumatic boosters, anti-freezers).

7. Check the condition and tightness of the hydraulic part of the brake system (main brake cylinders), pipelines, wheel cylinders, if necessary, eliminate the malfunctions.

8. Check the level of the brake fluid in the reservoir of the master brake cylinders, top up if necessary. If there is air in the system, bleed the system.

9. Check the condition and fastening of the front and rear wheels, fix if necessary.

10. Check the condition of the tires of the front and rear wheels, the pressure

air in tires.

11. Check the adjustment of the bearings of the front and rear wheel hubs, adjust if necessary.

12. Check the pressure in the tire of the rear (spare) wheel, if necessary, bring to normal.

13. Check the condition and tightness of the engine lubrication system, if necessary, eliminate the malfunctions.

14. Check the condition and tightness of the engine cooling system (radiator and its pipelines), if necessary, remove.

15. Check the condition and tension drive belts generator and water pump, power steering (GUR), intermediate support, fan shaft, adjust if necessary.

16. Check the condition, tightness and fastening of the fuel lines, fine filter, sump filter, fuel pump, if necessary, eliminate malfunctions.

17. Check the condition, tightness and fastening of the carburetor, if necessary, repair the malfunctions.

18. Check condition and fastening air filter, if necessary, secure.

19. Check condition and fastening fuel tank, if necessary, repair the malfunctions.

20. Check the fastening of the exhaust manifolds, tighten if necessary.

21. Check the condition, tightness, fastening of the exhaust pipes of the muffler to the manifolds, fix if necessary.

22. Check the condition and fastening of the brackets of the front engine mounts to the engine and subframe.

23. Check the condition and attachment of the rear engine mounts.

24. Check the condition and attachment of the subframe to the body, fix it if necessary.

25. Check the compressor attachment to the engine bracket.

26. Check the condition, tightness and fastening of oil lines and units (power steering pump, power cylinder, steering gear), if necessary, eliminate malfunctions.

27. Check the oil level in the reservoir of the power steering pump, top up if necessary.

28. Check the condition of the front axle beam.

29. Check the condition of the longitudinal and transverse steering rods, fastening of the ball pins of the steering rods.

31. Check the tightness and fastening of the master cylinder, if necessary, eliminate the malfunctions.

32. Check the condition, tightness and fastening of the pipeline, the clutch slave cylinder, the condition of the spring.

33. Check the amount of travel of the pusher of the clutch slave cylinder.

34. Check the fluid level in the reservoir of the clutch master cylinder, top up if necessary.

35. Check the free play of the clutch pedal, adjust if necessary.

36. Inspect and clean battery from dust and dirt, clean the ventilation holes in the plugs. Check the fastening of the contacts of the lugs with output pins.

37. Check the electrolyte level.

38. Check the operation of instrumentation, windscreen wipers, windscreen washers.

39. Check the operation of the sound signal.

40. Check the condition of the fuses, the operation of the external light signaling devices, their condition and fastening.

41. Check the condition and fastening of the headlights, the action of the light push switch.

42. Remove dirt and check the fastening of the generator, starter, ignition coil, transistor switch, condition and fastening of the wires.

43. Check the action of the door opening mechanism, its condition.

44. Check the condition, fastening and tightness of the gearbox (gearbox), the flange of the gearbox propeller shaft.

45. Check the fastening of the propeller shaft flange to the main drive pinion flange.

46. ​​Check the condition and tightness of the rear axle, the attachment of the reducer case to the rear axle mount.

47. Check the oil level in the engine crankcase using the dipstick, top up if necessary.

48. Clean the gearbox breather and the rear axle breather.

49. Lubricate the bearing of the water pump and the clutch release clutch.

50. Lubricate the hinges of the lateral and longitudinal steering rods.

51. Lubricate the bearings of the propeller shaft intermediate support.

In this chapter, in order to increase the technical readiness of the rolling stock and reduce the labor intensity of work on its maintenance, a maintenance program is calculated for a specialized section and the use of the flow method for the TO - 1 zone.

Grease KAMAZ 5320

Figure 3 Lubrication chart KAMAZ 5320

Table 17 Lubrication of assemblies

Continuation of table 17

Continuation of table 17