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


Check of a course of a pedal of a brake


    Press a pedal of a brake a hand. The free wheeling should make a maximum 1/3 from the general course of a pedal. Longer free wheeling of a pedal says that brake Pads have worn out till the minimum thickness and should be replaced. Too long course of a pedal can be caused and jammed brake колодками or приржавевшим a support of the brake mechanism. Probably, air has got to brake system.

Removal of a brake drum

At the removed brake drum in the brake mechanism of a back wheel we see following elements

1 – a lobby brake колодка;
2 – an adjusting wedge;
3 – the wheel brake cylinder;

4 – тросовый a drive of a lay brake;
5 – the lever of inclusion of a lay brake;
6 – back brake колодка.

The brake drum can be removed and without removing a wheel. In this case:


    To turn out one wheel bolt. To raise the car behind. To turn a wheel disk or a brake drum so that an aperture for a bolt it has appeared in front above on a car course. Through an aperture for a bolt to wring out an adjusting wedge upwards – thereby are wrung out brake Pads. To remove корончатый a wheel cap (the head the Suspension bracket and a steering). To unbend and take out safety шплинт in the bearing of a nave of a wheel. To remove корончатый a clamp, to turn on шестигранную a nut, to remove a persistent washer and the external bearing of a wheel. To remove a brake drum. At installation to adjust люфт the bearing of a nave of a wheel (the Suspension bracket and a steering see the head). To bring Pads to a brake drum by disposable strong pressing a brake pedal.

 The help: if at the old car it is impossible to wring out upward rusted adjusting wedge, ask the assistant to press a brake pedal – while you will wring out a wedge. Then it is necessary to release a pedal of a brake and only now to take out a screw-driver from an aperture, differently the wedge again will fall downwards. Watch that pressing a pedal was made only if both brake drums are established.

Check of a condition of brake drums


    The rubbing surface in a drum should be whenever possible smooth. If deep furrows or scratches are visible (because of worn out to rivets brake колодок), the drum can be chiseled. Internal diameter of new brake drums makes 230 mm. After расточки internal diameter should not be more than 231 mm, otherwise it is necessary to replace both brake drums. It is necessary to apply thicker to the chiseled brake drums Pads.

Removal of the cylinder of the drum-type brake mechanism

Parts of the removed drum-type brake mechanism. Arrows show, where it is necessary to hang springs.

1 – a lobby brake колодка;
2 – a clip with a spring, a spring plate and a fixing pin;
3 – a press bar;
4 – a returnable spring;
5 – an adjusting wedge;
6 – a tension spring of an adjusting wedge;

7 – the bottom returnable spring;
8 – the basic spring;
9 – the lever of inclusion of a lay brake;
10 – a frictional overlay on back brake колодке;
11 – a clip.


    To remove a brake drum. To remove brake Pads. To turn out the prorolling valve. To disconnect a brake hose. If you are not going to establish at once the new brake cylinder it is necessary to squeeze out a pedal of a brake and to leave it in this position, to prevent unnecessary loss of a brake liquid. To take out two fixing bolts behind on a guard of the drum-type brake mechanism and to remove the brake cylinder.

Removal brake колодок


    To remove a brake drum. To wring out пассатижами a spring plate of the holder brake колодок, to turn on 90 (holding a fixing pin behind at a guard that it did not rotate together with a guard) and to remove them, then to remove springs. To unhook a returnable spring of an adjusting wedge. To separate brake колодку from the bottom support and the piston of the brake cylinder. To extend an adjusting wedge from a press bar. To fasten the basic spring to a press bar and brake колодке. As it is necessary to establish a spring, it is shown in drawings. To establish brake колодку on a press bar, to insert from above an adjusting wedge. Its ledge is directed towards brake Pads. To establish the brake lever passive Pads in a ledge of a press bar, to fasten the top returnable spring. To hang a cable of a drive of a lay brake at yet not fixed brake колодках on the lever of inclusion of a lay brake.