Audi 80/Avant (B4)

since 1991-1995 release

Repair and operation of the car

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
+ System of injection
+ Coupling
+ Transmission and transmission
+ Suspension bracket and steering
- Brake system
   Check of brake mechanisms
   Brake fluid
   Check of level of brake fluid
   Check of tightness of brake system
   Replacement of brake fluid
   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 brake mechanism
   Measurement of brake shoes of the drum mechanism
   Check of the 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 the hydraulic drive of brakes
   Pumping of brake system
   List of malfunctions
+ Anti-blocking system of brakes
+ Wheels and tires
+ Body electrical system
+ System of ignition
+ Lighting
+ Signalling devices
+ Devices and auxiliary devices
+ Heating and ventilation
+ body Elements
+ Search of malfunctions
+ Specifications

Replacement of blocks of disk brake mechanisms

Essentially on the right or at the left it is necessary to replace both blocks. It is possible to apply only blocks with "The general admission to operation" (in German "Allgemeine Betriebserlaubnis" – ABE).

Brake Girling mechanism: to turn out only the lower fixing bolt (2) cases of a support of the disk brake mechanism. To hold a napravlyashchy bolt. The top fastening (1) remains untouched. At installation to apply new samokontryashchiysya a fixing bolt!

Brake Ate mechanism: after removal of a cap (3) to weaken the lower bolt with an internal hexagon in protective plugs (4).

In the brake mechanism of the producer of Girling are necessary for replacement of blocks in total two new samokontryashchikhsya a bolt. In most cases they enter a set with brake shoes – to check! If the brake mechanism from the producer of Ate, bolts are not required to you.

As pistons in supports of brake mechanisms with the increasing wear of blocks leave farther, before installation of new, thicker blocks they need to be put into place. Thus brake fluid is squeezed out via the pipeline in a receiver. If in the past the excessive amount of unnecessary liquid was added, this surplus now needs to be pumped out. Otherwise the acting brake fluid will spill on the metal details located in a motor compartment. It is necessary to apply only absolutely pure pipette or an old medical syringe to pumping out – at all do not suck away a mouth!


  1. To raise the car in front and to record.
  2. To remove a wheel.
  3. To turn a steering wheel that it was possible to reach blocks easily.
  4. Brake Ate mechanism: to take off a cap on bracket inside. To insert a face key into the internal hexagon of a bolt opened now and to weaken it.
  5. To turn off only the lower bolt.
  6. To extend a bolt, to cast away a bracket of a support of the disk brake mechanism up or – if both bolts were removed – to remove.
  7. To suspend the removed bracket on a wire to a depreciation rack.
  8. Brake Girling mechanism: to unscrew only the lower fixing bolt of the case of a support of the disk brake mechanism, holding thus the directing bolt for a six-sided head.
  9. To cast away a bracket upward.
  10. Both versions: on the right and at the left to take out blocks from the directing tires.
  11. By means of a clamp to wring out a rod inside. In order that the piston did not warp or damaged, put a small plate on a lock ring.
  12. At the two-piston brake mechanism it is necessary in the same way to wring out both brake rods together or separately.
  13. Pay attention to the correct landing of a heat-shielding guard in the piston cylinder.
  14. To establish new blocks.
  15. To put into place a support.
  16. Brake Ate mechanism: to tighten the directing bolt the moment of 25 N • m and again to put on a cap.
  17. Brake Girling mechanism: to tighten lower (the new!) fixing bolt moment of 35 N • m. Not to dozatyagivat the top bolt, differently it will be terminated samokontryashcheesya. Hold the directing bolt with thin Rozhkov a wrench, differently will clamp it, and in this case force of an inhaling will be incorrect.
  18. After assembly several times press a brake pedal until blocks do not nestle on brake disks. Otherwise there will be no brake influence!

 Help: when passing the first 500 km with new brake shoes brake whenever possible more carefully.

Removal of a forward support of the disk brake mechanism

The Dvukhporshnevy disk brake mechanism with a floating bracket of 6-cylinder models

1 – case of a support of the disk brake mechanism;
2 – brake piston;
3 – brake shoes;

4 – the lower directing;
5 – brake disk;
6 – support of the brake mechanism.

The case of a support of the disk brake mechanism (1) of 4-cylinder model will be cast away after removal of the lower fastening (4) up. Blocks (3) for the present stand in the directing. Further are visible:

2 – a heat-shielding guard in the brake piston;
5 – brake disk;
6 – support of the brake mechanism.

Each of forward supports of disk brake mechanisms is strengthened on a depreciation rack by two so-called corrugated bolts. At these bolts behind a six-sided head the corrugated surface preventing casual easing or loss of a bolt is located. These corrugated bolts cannot be replaced usual by no means!


  1. To remove a wheel.
  2. To remove brake shoes.
  3. To weaken fixing bolts of a support of the brake mechanism.
  4. To hang out a support of the brake mechanism with the connected hose so that the hose was not tense.
  5. Or to pick up a brake hose or the phone.
  6. To press a pedal of a brake and to hold it to prevent an effluence of brake fluid.
  7. Before installation to clear corrugated surfaces of ridge bolts.
  8. To tighten corrugated bolts the moment of 125 N • m.
  9. Again to establish a brake hose or a tube.
  10. To remove air from brake system in case the brake pipeline or a hose was removed.
  11. Before a start of motion several times to press a brake pedal until the normal course of a pedal is established.

Replacement of cuffs of brake pistons

On an illustration the piston of the cylinder of the disk brake mechanism is moved by means of a clamp in order that it was possible to establish new brake shoes. For protection we enclosed a small wooden plate. The support of the brake mechanism of the producer of Girling removed for the photo usually remains fixed on the top bolt.

If the cuff of the brake piston in a support of the disk brake mechanism was damaged, you need to replace as soon as possible it, differently the brake piston soon will start jamming because of dirt and corrosion. The cuff can be got only complete with a sealing ring of the brake piston. For installation of both details it is necessary to take the piston from the case of the brake cylinder.

It is for safety reasons better to charge this work of a workshop. For example, to remove a support of the disk brake mechanism and to bring it to a workshop.

Replacement of a forward brake disk

Brake disks need to be changed from both parties at the same time. Unilateral replacement will lead to uneven brake action.


  1. To disconnect a support of the disk brake mechanism and to strengthen it a wire on a body; hoses remain connected.
  2. To turn out a bolt with crosswise shliyets (near an opening for wheel bolts).
  3. To process a bolt means for removal of a rust or to apply pulse boltovert.
  4. Now it is possible to remove a hand a brake disk from a wheel nave.
  5. If it prirzhavet, to help in sharp blows of a hammer but only in case this disk anyway has to change.
  6. Before installation of a new brake disk to clear a prileganiye surface on a wheel nave.