Brake system of cars VAZ-2121

All articles about the device and repair of units and elements of the brake system of VAZ-2121 Niva cars and their modifications.

Brake system diagram
The diagram of the braking system is shown in Fig. 6-1. Fig. 6-1. Brake system diagram: 1 - front brake cylinder block; 2 - brake hydraulic fluid reservoir; 3 - master brake...

Possible brake malfunctions, their causes and methods of elimination
Insufficient braking efficiency Spontaneous braking with the engine running Incomplete release of braking of all wheels Braking of one of the wheels with the brake pedal released...

Checking and adjusting brakes, checking pipes and connections
To prevent sudden failure of the brake system, carefully check the condition of all pipes: metal pipelines should not have dents, cracks and should be located away from sharp...

Checking the performance of the vacuum booster
Press the brake pedal 5-6 times with the engine off to create equal pressure close to atmospheric in cavities A and E (Fig. 6-2). At the same time, by the force applied to the...

Adjusting the brake drive
The free travel of the brake pedal with the engine off should be 3-5 mm. This value is obtained by adjusting the position of the switch 6 (Fig. 6-3) of the brake light. Fig. 6-3....

Adjusting the parking brake
If the parking brake does not hold the vehicle on a slope of up to 30° or is engaged when the lever is moved more than 4-5 teeth of the ratchet device, adjust it in the following...

Checking the performance of the pressure regulator
Place the car on a lift or inspection pit, clean the pressure regulator and protective cover from dirt. Carefully remove the protective cover from the pressure regulator, remove...

Adjusting the clearance between the pads and the drum
The adjustment procedure is as follows: press the brake pedal with a force of 98-117.5 N (10-12 kgf) to ensure that the pads adhere to the drum; holding the pads in this position,...

Adjusting the position of the pressure regulator
If the bolts securing the pressure regulator have loosened, adjust its position by first raising the rear axle of the vehicle. Then disconnect lever 4 (Fig. 6-6) from rod 8 and...

Removal air from the hydraulic drive
Air that gets into the brake hydraulic system when replacing pipes, hoses, sealing rings or when the system is leaking causes an increase in the free travel of the brake pedal,...

Clutch and brake pedal bracket
Removal and installation To remove the pedal bracket: remove the steering shaft bracket as described in the "Steering" section; disconnect the vacuum booster pushrod from the...

Vacuum booster — removal and installation
When removing the booster, the master cylinder of the brake hydraulic drive is not disconnected from the hydraulic system to prevent air from getting into it. The order of...

The device of the main cylinder of the brake drive
The design of the brake master cylinder is shown in Fig. 6-10. Fig. 6-10. Master cylinder of the hydraulic brake drive: 1 - cork; 2 - cylinder body; 3 - front brake actuator...

Master Cylinder — Removal and Installation
Disconnect the flexible hoses from the master cylinder and plug the hose openings and fittings on the cylinder to prevent fluid from leaking from the reservoir and dust, dirt or...

Master Cylinder — Disassembly and Assembly
Remove fittings 3 (Fig. 6-11) with sealing washers 4. Remove cap 5, unscrew lock bolts 7 and remove all parts in the order shown in Fig. 6-11. Fig. 6-11. Brake master cylinder...

Master Cylinder — Checking Parts
Before assembly, wash all parts with isopropyl alcohol; dry them with a jet of compressed air or wipe them with a clean cloth, avoiding contact with mineral oil, kerosene or...

Checking the tightness of the master cylinder
Install the master cylinder on the stand and connect it to the stand elements as shown in Fig. 6-12. Fig. 6-12. Master cylinder tightness test diagram: 1 - valve for bleeding the...

Front brake device
The front brake device is shown in Fig. 6-13. Fig. 6-13. Front wheel brake mechanism: 1 - cylinder block; 2 - brake pads; 3 - caliper clamping lever; 4 - protective cover; 5 -...

Front brakes — removal and installation
Removal Raise the front of the car, place it on stands and remove the wheel. Remove the hose guide brackets. Unscrew the bypass bolts, disconnect the hoses 10 ( fig. 6-13 ), while...

Front brakes — disassembly and assembly
Remove the cotter pins, then the axles 5 ( fig. 6-13 ), holding the pressure levers 3 so that the springs do not jump out. Remove the pressure levers and their springs, and then...

Front Brakes — Checking Parts
Check all parts carefully, after washing them with warm water and detergent and drying them with a jet of compressed air. If traces of wear or seizure are found on the pistons and...

Front brakes — checking brake disc runout
Check the axial runout of the brake disc without removing it from the vehicle (Fig. 6-16). The maximum permissible runout according to the indicator is 0.15 mm; if the runout is...

Front Brakes — Replacing Brake Pads
The pads are replaced with new ones if the thickness of the linings has decreased to 1.5 mm. To replace the pads, perform the following operations: unpin the upper clamping lever...

Rear brake device
The rear brake device is shown in Fig. 6-18. Fig. 6-18. Rear wheel brake mechanism: 1 - wheel cylinder; 2 - manual brake pad drive lever; 3 - brake shoe; 4 - cup and support post...

Rear brakes — removal and disassembly
Raise the rear of the car and remove the wheel. Take measures to prevent fluid leakage from the tank. Using puller 67.7823.9519 (Fig. 6-19), remove the brake drum. Fig. 6-19....

Rear brakes — assembly and installation
Install the wheel cylinder on the brake shield and connect the brake fluid supply pipe to it, tighten the nipple nut until it stops Attach lever 2 (to the shoe see fig. 6-18 )...

Rear Brakes — Checking Parts
Wheel cylinders Disassemble the wheel cylinders, for which remove the protective caps 1 (Fig. 6-20) and pistons 2, take out the seals 3, support cups 5 and spring 7. Then unscrew...

Rear Brake Pressure Regulator — Removal and Installation
Disconnect lever 12 (Fig. 6-22) from rod 7, and then collar 18 from bracket 14 and the bracket for fastening the pipes going to the pressure regulator. Fig. 6-22. Pressure...

Rear Brake Pressure Regulator — Disassembly and Assembly
Using key A.56124, unscrew the plug, remove gasket 5 (Fig. 6-23), take out piston 10, spacer sleeve 2, seal 7, plate 8, spring 9 and thrust washer with sealing ring 3. Fig. 6-23....

Parking brake — removal and installation
With the parking brake drive lever in its lowest position, disconnect the ends of the cables from the brake shoe drive levers (see " Rear brakes "). Loosen the locknut 5 ( fig....

Parking brake — inspection and repair
Carefully check the condition of the parking brake components. If a break or fraying of the wires is detected, replace the cable with a new one. Make sure that the sector teeth...

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More articles from other manuals on VAZ cars:
➠ Chassis: Brake system VAZ-21051 (1979-2010)
➠ Chassis: Brake system VAZ-2101 (1970-1983)
➠ Chassis: Brake system VAZ-2110 (1995-2007)
➠ Chassis: Brake system VAZ-2107 (1982-2012)
➠ Chassis: Brake system VAZ-1111 (1988-1996)

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