Audi 80/Avant (B4)

since 1991-1995 of release

Repair and car operation

Audi 80/Avant
+ Technical specification
+ Engines
+ System of production of the fulfilled gases
+ cooling System
+ Fuel tank and fuel pump
+ Air filter and airintaking channels
+ injection System
+ Coupling
+ Transmission and transmission
+ Suspension bracket and steering
- Brake system
   Check of brake mechanisms
   Brake liquid
   Check of level of brake liquid
   Check of tightness of brake system
   Replacement of brake liquid
   Disk brake mechanisms
   Measurement of thickness of blocks of the disk mechanism
   Control of a condition of brake disks
   Replacement of blocks of disk brake mechanisms
   Drum-type brake mechanism
   Measurement of brake shoes of the drum-type mechanism
   Check of a course of a pedal of a brake
   Disk brake mechanism of back wheels
   Measurement of thickness of blocks of back disk brakes
   Check of a free wheeling of the lever of the parking brake
   Main brake cylinder
   Amplifier of brakes
   Check of the amplifier of brakes
   Regulator of brake forces
   Repair of a hydraulic drive of brakes
   Pumping of brake system
   List of malfunctions
+ Anti-blocking system of brakes
+ Wheels and tires
+ Body electrosystem
+ ignition System
+ Lighting
+ Signalling devices
+ Devices and auxiliary devices
+ Heating and ventilation
+ body Elements
+ Search of malfunctions
+ Specifications

Measurement of thickness of blocks of back disk brakes

Hummock drive of system of the parking brake at the case of a support of the disk brake mechanism of models with disk brakes on back wheels


1–tip of a hummock drive of the parking brake; 2–driving lever of a support of the brake mechanism of the parking brake; 3–returnable spring of a hummock drive of the parking brake;	4–spring bracket; 5–cover of a hummock drive of the parking brake.

Check of thickness of brake shoes:

6–material of a frictional slip;
7–carrier of a frictional slip.

On back disk brake mechanisms control of wear of blocks occurs in the same way, as well as on lobbies. Limiting wear and here makes 2 mm – without thickness of a plate carrier.

At the same time with control of wear of blocks check of a condition of brake disks is carried out. Indicators of wear and sequence of works same, as well as at check of forward disk brake mechanisms.

Replacement of brake shoes of back disk brakes

Except blocks, four are necessary самоконтрящихся a bolt which, as a rule, enter into a set with blocks. In spite of the fact that work легковыполнима, nevertheless you can face problems if there is no special key 3131 of Audi workshop.

The below-mentioned description, thus, can help only on condition that you can hire this key in a workshop or make it on a sample.

On an illustration a special key 3131 from a workshop of Audi push back the brake piston of the back disk brake mechanism at the removed support of the brake mechanism.

PERFORMANCE ORDER

To turn out both fixing bolts of the case of a support of the disk brake mechanism, holding thus directing bolt for a shestigrannik.
Hand to pull the support case to outer side of the car.
Now to cast away it back and to remove.
To take out brake shoes from the directing.
To establish a special key 3131 to the brake piston and to screw the piston in strong pressing of a hand.
Ask the assistant to watch thus level of brake liquid in a tank. If the tank is overflowed, it is necessary to pump out liquid.
Never push the brake piston without rotation with a great effort. In this case you will destroy the adjusting mechanism in the piston.
To establish new blocks.
To tighten the case of a support of the disk brake mechanism new самоконтрящимися bolts the moment of 35 N • m.
To a priderzhivaniye of a directing bolt to apply only a thin rozhkovy wrench. Wide can jam, and force of an inhaling in this case will not coincide.
After dismantling of the brake mechanism it is necessary to make surely the main adjustment (see the following section).

Adjustment of disk brakes of back wheels

PERFORMANCE ORDER

To raise the car behind from both parties and to fix. To remove wheels.
To remove from the parking brake.
To check, that hummock drives of system of the parking brake were not under a preliminary inhaling.
For control to wring out the lever of inclusion of system of the parking brake on a support of the brake mechanism alternately to the right and to the left against the stop.
If the lever of a support of the brake mechanism of other wheel, also moves, means, cables of a drive of the parking brake are tense too strongly. In this case to weaken the central adjusting nut of system of the parking brake, until then while both levers will not reach precisely against the stop.
To put the car on wheels.
At the switched-off engine to press a brake pedal with average force about 40 times.
Again to raise the car.
To check, whether wheels can freely rotate.

Removal of a support of back disk brakes

PERFORMANCE ORDER

To disconnect a brake hose in case it is necessary to replace a support of the brake mechanism.
To remove the case of a support of the brake mechanism as for replacement of blocks. Pay thus attention to the text above!
To remove hummock drives of system of the parking brake.
To turn out both fixing bolts of the support being on an axis.
At installation to tighten fixing bolts of a support the moment of 65 N • m.
Carry out once again adjustment.

Replacement of cuffs of back brake cylinders

Replacement of defective cuffs of brake pistons on back supports of disk brake mechanisms occurs as well as on lobbies.

Replacement of a back brake disk

PERFORMANCE ORDER

To remove a support of the disk brake mechanism.
To remove a brake disk.
To clear a prileganiye surface on a nave of a wheel or to smooth out a small skin and to put on a new brake disk.
To carry out adjustment according to the described scheme.

System of the parking brake

When actuating the lever of inclusion of system of the parking brake rigid draft under a car floor forward moves. On its end there is a yoke – a counterbalancing bracket. The cables of a brake drive going back to guards of brake drums or to supports of brake disks are attached to it. Purpose of a counterbalancing bracket consists in whenever possible evenly to distribute between back wheels force which is enclosed at a tightening of the lever of the parking brake. Fluctuations of factor of a friction of both cables of a brake are counterbalanced by a yoke.

At models with back drum-type brake mechanisms cables of a drive pull for levers of inclusion of system of the parking brake of back brake shoes and press them to a drum. At the same time the lever of inclusion of system of the parking brake leans through a press bar on a forward brake shoe. Thereby it also brakes.
On models with back disk mechanisms cables of a brake drive affect via the driving lever, a press bar and the adjusting mechanism with the way described in the section «Disk brake mechanisms of back wheels».