The rear brakes are automatically adjusted, it is only necessary to check the thickness of the brake linings at specified intervals. Automatic adjustment is carried out by an expanding rod with a variable length. Namely, a spring-loaded wedge is located between the shoes and the expanding rod. After a single press of the brake medal, an air gap is established between the brake shoe and the drum. If the movement of the brake shoe, due to wear of the lining, exceeds the set gap, the wedge moves down, due to which the length of the expanding rod increases and the gap decreases. Brake fluid for the entire brake system and the hydraulic clutch drive comes from a reservoir, which is located in the front part of the engine compartment. The pressure for both brake circuits is created in the master brake cylinder using the brake pedal.
The hydraulic brake booster uses part of the reduced pressure generated by the engine for its operation. 100 kW (136 hp) engines and diesel engines have a special vacuum pump that ensures the operation of the booster and is located on the cylinder head.
The handbrake acts on the brake shoes of the rear wheels via a cable drive.
For AUDI 80/90, Teves and Girling disc brake calipers are used. The work on replacing the pads is carried out differently.
When cleaning the brake system, brake dust is released. This dust can cause health problems. Therefore, when cleaning, pay attention to the fact that brake dust is not inhaled.
Brake pads are a part of the "General Operating Permit" and also vary depending on the model produced by the factory. Therefore, it is recommended to use VAG brake pads.
Work on the brake system requires exceptional cleanliness and precision. In the absence of experience, work should be carried out at a service station.
Note: On wet roads, you should press the brakes from time to time to free the discs from foreign objects. Although centrifugal force throws water off the brake discs while driving, a thin film of silicones, rubber waste, grease and other contaminants remains on them, reducing braking efficiency.
After driving in the rain or in winter, it is advisable to dry the brakes by gently pressing them before stopping. This will also slow down the corrosion of the brake discs.
After installing new brake pads, they must be worked in. Avoid unnecessary full braking during the first 200 km.
Rusty disc brakes create a grater effect when braking, which cannot be eliminated even with prolonged braking. In this case, the brake discs must be replaced.
Burnt dirt on the brake pads and clogged drainage grooves cause grooves on the brake disc. This reduces the braking effect.
Caution: If the pedal travel changes after cornering, the brake disc must be checked for lateral runout on the outside diameter. If necessary, the brake disc must be replaced.
A link to the original source is available on the website: AUDImanual