Audi 80/Avant (B4)

Since 1991-1995 of release

Repair and car operation

Audi 80/Avant
+ The description
+ Engines
+ System of release of the fulfilled gases
+ Cooling system
+ Fuel tank and the fuel pump
+ The air filter and воздухозаборные channels
+ Injection system
+ Coupling
+ Transmission and transmission
+ Suspension bracket and steering
- Brake system
   Check of brake mechanisms
   Brake liquid
   Check of level of a brake liquid
   Check of tightness of brake system
   Replacement of a brake liquid
   Disk brake mechanisms
   Measurement of a thickness колодок the disk mechanism
   The control of a condition of brake disks
   Replacement колодок disk brake mechanisms
   The drum-type brake mechanism
   Measurement brake колодок the drum-type mechanism
   Check of a course of a pedal of a brake
   The disk brake mechanism of back wheels
   Measurement of a thickness колодок back disk brakes
   Check of a free wheeling of the lever of a lay brake
   The main brake cylinder
   The amplifier of brakes
   Check of the amplifier of brakes
   Regulator of brake forces
   Repair of a hydraulic drive of brakes
   Prorolling of brake system
   The list of malfunctions
+ Antiblocking system of brakes
+ Wheels and tyres
+ Kuzovnaja electrosystem
+ Ignition system
+ Illumination
+ Signalling devices
+ Devices and auxiliary devices
+ Heating and ventilation
+ Body elements
+ Search of malfunctions
+ Specifications


The amplifier of brakes

Disk brake mechanisms do not operate in the self-amplifying image, as, for example, the drum-type. Much higher brake force is necessary. Therefore Audi 80 it is supplied by the pneumatic amplifier of a brake drive adding about 60 % of brake force. Despite it, the brake pedal is directly connected with the brake piston in the main brake cylinder so it is possible to brake and at the failed amplifier. But necessary pressure upon a pedal in this case needs to be increased several times.

Additional force is provided with the lowered pressure from an inlet collector. The amplifier of brakes is connected by a hose with a final collector. At braking the difference in pressure between external pressure of air and the lowered pressure in a final collector shifts the big elastic diaphragm and in addition presses on the piston in the main brake cylinder. If the engine is not got, the amplifier cannot develop any (additional) brake force. If the engine suddenly глохнет still there is a small reserve for a quantity of braking; but then it is necessary to hope only for force of feet.

The vacuum pump

For improvement поддерживания brake force the 5-cylinder engine is equipped by the additional vacuum pump established at the left at a head of the block of cylinders and set in motion by a camshaft. Thanks to it the lowered pressure in hoses to the amplifier of brakes increases.