Audi A4, S4

since 2000 release

Repair and operation of the car


Audi A4, S4
+ Introduction
+ Governing bodies and methods of safe operation
+ Current leaving and service
+ Engine
+ Cooling systems, heating and air conditioner
+ Power supply systems, release and decrease in toxicity of the fulfilled gases
+ Systems of electric equipment of the engine
+ Manual box of gear shifting
+ Automatic transmission
+ Coupling, power shafts and differential
- Brake system
   Specifications
   Removal of air from brake system
   Removal and installation of front brake shoes
   Removal and installation of blocks of brake mechanisms of back wheels
   Check of thickness of a brake disk
   Removal and installation of a brake disk / support
   Adjustment of the parking brake
   Removal and installation of the switch of a stoplight
   Removal and installation of a brake hose
+ Suspension bracket and steering
+ Body
+ Onboard electric equipment





Removal and installation of front brake shoes

FN-3 support

By means of illustrations, find out execution of the support established on your car.

Forward brake FN3 mechanisms

1 — the Cover of a brake disk
2 — the Screw, 10nm
3 — the Brake hose. When replacing brake shoes not to turn off.
4 — the Holder. Fastens to the support case
5 — the Bolt, 10nm
6 — the Spring bracket
7 — the Brake pipeline, 15nm. It is rolled in the case of a support and connects to a brake hose. Thus it is necessary to hold for a hexagon of a brake hose. Watch reliable position of lock pads in the holder's grooves
8 — the wear sensor Socket. When replacing a brake shoe it is taken out from the holder (4)
9 — the Bolt with a gear fillet, 190nm. At repeated application clear teeths.
10 — Directing. Fastens to the wheel bearing case
11 — Brake shoes
All four blocks of one axis are surely replaced. Instruction: The internal block has an arrow. The arrow has to specify in the direction of rotation of a brake disk at the movement of the car forward. At the wrong installation can lead to emergence of noise.
External brake shoes have a sticky film on the return plates. The protective film before installation of blocks needs to be removed.

At achievement of the corresponding wear (2 – 3 mm) on the dashboard the control lamp lights up. Pay attention to various executions of brake shoes (the catalog of spare parts). Before installation of new blocks the support needs to be cleared carefully. On the directing surfaces of blocks it is necessary to apply a thin film of lithium G 052 142 A2 greasing of AUDI firm.
12 — the Lock spring. It is inserted into support case openings. Instruction: After installation the lock spring needs to be pressed into openings under the directing. At the wrong installation wear of an external block can not be compensated that will lead to increase in the course of a pedal of a brake
13 — the Brake disk. Both brake disks of one axis are surely replaced. For removal it is necessary to disconnect only a support
14 — the support Case. For replacement of brake shoes disconnect from the directing
15 — the Directing finger, 25nm
16 — the Cover
Instruction: All bolts and screws located outside have a sheeting.

Removal

 PERFORMANCE ORDER

  1. Mark the direction of its rotation on the tire. Turn off bolts of fastening of a wheel. Lift and establish forward part of the car on supports and remove a wheel.

Surely observe instructions in the Section In case of emergency.

If brake shoes are established again, they need to be marked at removal. Change by places of external and internal brake shoes, and also their shift with right on the left wheel is not allowed. Surely all brake shoes of forward wheels are replaced at the same time even if the limit of wear was reached by a brake shoe of one party.

  1. Uncover (shooters on an accompanying illustration) both directing fingers.
  1. Disunite the socket (1) index of wear of brake shoes in the presence of the last. Turn on 90 ° a lock level of the lower part of the plug.
  1. Take out the lower part of the plug from the holder.
  1. Hook a screw-driver and take out from an opening (the shooter on an accompanying illustration) a lock spring of a brake shoe.
  1. Turn out from a support both directing a finger.
  1. Remove the case of a support and fix it a wire to a suspension bracket.

Do not allow a tension of a brake hose.

  1. Remove an external brake shoe from the directing.
  2. Take out an internal brake shoe with a spring from the brake piston.

Installation

At the removed brake shoes do not press a brake pedal, otherwise the piston can be squeezed out from the case. In this case remove a support in a set and ask it to insert into place on HUNDRED.

 PERFORMANCE ORDER

  1. Before installation of blocks into place check palpation by fingers a brake disk. In the presence of flutes a disk it is possible to pierce (work HUNDRED) if it still allows thickness.
  2. Measure thickness of a brake disk, address to appropriate section.

Apply to cleaning of a disk only alcohol. Clear the directing surface and places of landing of blocks in mine of the case a rag. Do not use for this purpose the tool with sharp edges. Pay special attention to removal of the remains of a sticky film on adjacent surfaces of external brake shoes.

  1. Check a piston boot for existence of cracks. Immediately replace the damaged boot since the got dirt quickly leads to loss of tightness of a support. Thus it is necessary to sort a support (work HUNDRED).

At big wear of a brake shoe check ease of a piston stroke. For this purpose insert wooden whetstone into a support and ask the assistant to press a brake pedal slowly. The piston has to leave and enter easily. For check other support has to be established. Watch that the piston completely was not squeezed out. At a heavy piston stroke hand over a support in repair on HUNDRED. Press the piston the tool shown on an accompanying illustration.

It can be made also by means of wooden whetstone (the hammer handle). Thus watch that the piston not to warp the piston and not to damage a piston surface, and also a boot.

At cave-in of the piston brake fluid is squeezed out from the brake cylinder in the tank. Watch liquid in the tank, if necessary, suck away liquid by means of a siphon.

  1. Apply a plastic bottle which is intended only for this purpose to suction of brake fluid. Do not apply for this purpose a bottle to drinking liquid! Brake fluid is poisonous and should not be sucked away by a mouth through a hose at all. Apply for this purpose a siphon. When replacing brake shoes the level of brake fluid in the tank should not exceed MAX mark since liquid when heating extends. The following liquid gets on the main brake cylinder, destroys its covering and brings corrosion.
  2. Before installation of new brake shoes carefully clear them and grease with a thin layer of lithium G 052 142 A2 greasing.
  1. Insert an internal brake shoe with about a lock spring into the brake piston.


    1 — the Internal brake shoe of the right wheel
    2 — the Internal brake shoe of the left wheel <