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 the 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 the brake system
   List of malfunctions
+ Anti-blocking system of brakes
+ Wheels and tires
+ Body electrical system
+ System of ignition
+ Lighting
+ Signaling devices
+ Devices and auxiliary devices
+ Heating and ventilation
+ Body elements
+ Search of malfunctions
+ Specifications





Check of the course of a pedal of a brake

 PERFORMANCE ORDER

  1. Press a brake pedal a hand.
  2. The free wheeling has to make at most 1/3 from the general course of a pedal.
  3. Longer free wheeling of a pedal says that brake shoes wore out to the minimum thickness and have to be replaced.
  4. Too long course of a pedal can be caused also by the jammed brake shoes or the rusted support of the brake mechanism.
  5. Perhaps, air got to the brake system.

Removal of the brake drum

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

1 – front brake shoe;
2 – adjusting wedge;
3 – wheel brake cylinder;

4 – hummock drive of the parking brake;
5 – lever of turning on of the parking brake;
6 – back brake shoe.

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

 PERFORMANCE ORDER

  1. To turn out one wheel bolt.
  2. To raise the car behind.
  3. To turn a rim or the brake drum so that the opening for a bolt appeared in front above on the car course.
  4. Through an opening for a bolt to wring out an adjusting wedge up – brake shoes thereby are wrung out.
  5. To take off a koronchaty cap of a wheel (the head Podvesk and steering).
  6. To unbend and take out the safety forelock in the wheel bearing.
  7. To remove a koronchaty clamp, to turn off a six-sided nut, to remove a persistent washer and the external bearing of a wheel.
  8. To remove the brake drum.
  9. At installation to adjust a side play of the wheel bearing (see the head Podvesk and steering).
  10. To bring blocks to the brake drum by one-time strong pressing a brake pedal.

 Hint: if at the old car it is impossible to wring out upward the rusted adjusting wedge, ask the assistant to press a brake pedal – while you wring out a wedge. Then it is necessary to release a pedal of a brake and only now to take out the screw-driver from an opening, otherwise the wedge will fall again down. You watch that pressing a pedal was made only if both brake drums are installed.

Check of a condition of brake drums

 PERFORMANCE ORDER

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

Removal of the cylinder of the drum brake mechanism

Parts of the removed drum brake mechanism. Shooters show where it is necessary to hang springs.

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

7 – lower returnable spring;
8 – main spring;
9 – lever of turning on of the parking brake;
10 – a frictional slip on a back brake shoe;
11 – clip.


 PERFORMANCE ORDER

  1. To remove the brake drum.
  2. To remove brake shoes.
  3. To turn out the pumping valve.
  4. To disconnect a brake hose. If you are not going to install at once the new brake cylinder, then it is necessary to squeeze out a pedal of a brake and to leave it in this situation to prevent unnecessary loss of brake fluid.
  5. To take out two fixing bolts behind on a guard of the drum brake mechanism and to remove the brake cylinder.

Removal of brake shoes

 PERFORMANCE ORDER

  1. To remove the brake drum.
  2. To wring out passatizham a spring plate of the holder of brake shoes, to turn on 90 ° (holding a fixing pin behind at a guard that he did not rotate together with a guard) and to remove them, then to remove springs.
  3. To unhook a returnable spring of an adjusting wedge.
  4. To separate a brake shoe from the lower support and the piston of the brake cylinder.
  5. To extend an adjusting wedge from a press bar.
  6. To fasten the main spring to a press bar and a brake shoe. As it is necessary to establish a spring, it is shown in drawings.
  7. To establish a brake shoe on a press bar, to insert from above an adjusting wedge. Its ledge is directed towards a brake shoe.
  8. To install the brake lever of a passive block in a ledge of a press bar, to fasten the top returnable spring.
  9. To hang a cable of the drive of the parking brake at yet not recorded brake shoes on the lever of turning on of the parking brake.







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