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
- Suspension bracket and steering
   Security measures at work
   + Suspension bracket of forward wheels
   + Suspension bracket of back wheels
   + Corners of installation of wheels of the car
   - Steering and safety cushions
      General information and security measures
      Removal and installation of the block of a safety cushion
      Removal and installation of a steering wheel
      Removal and installation of a tip of steering draft
      Removal and installation of a protective cover of the steering mechanism
+ Body
+ Onboard electric equipment

Steering and safety cushions

General information and security measures

Elements of a hydraulic system of the steering mechanism. 4-cylinder engine and 6-cylinder diesel engine

1 — the Steering mechanism with hydrostrengthening
2 — Gidroprovod of a high pressure
3 — the Drain hose
4 — the Cover with the index of level of oil
5 — the Bolt, 5nm
6 — the oil Tank
7 — the Rubber support
8 — the Collar
9 — the Returnable hose
10 — the Collar, surely replace
11 — the Bolt, 10nm
12 — the cooling Pipeline
13 — the Collar elastic
14 — the Collar *

15 — the Soaking-up hose
16 — the Collar *
17 — the Pump bladed the 6-cylinder diesel engine
18 — the Sealing ring *
19 — the Sealing ring *
20 — the Hollow screw, 47nm
21 — the Pump bladed the 4-cylinder engine
22 — the Sealing ring *
23 — the Sealing ring *
24 — the Hollow screw, 47nm
25 — the Soaking-up hose
26 — the Collar
*) Surely replace

Steering column

The steering consists of a steering wheel, a steering column, the steering mechanism in the form of gear and rack transfer and drafts of the steering drive. The steering column transfers the movements of a steering wheel to the steering mechanism. The gear lath of the steering mechanism according to turn of a steering wheel moves to the right or to the left. Steering drafts transmit steering efforts to forward wheels through hinges and a rotary fist.

Gear and rack transfer of the steering mechanism - bezzazorny and not demanding service. Within carrying out maintenance only control of protective covers and boots of tips of steering drafts is required.

The hydraulic booster providing decrease in the effort made for a steering wheel has a steering of the car. The hydraulic booster contains a hydraulic pump and the tank of working liquid. The hydraulic pump sucks in liquid from the tank and gives it under a high pressure to the operating valve in the steering mechanism. The operating valve has mechanical communication with a steering spindle and directs liquid, depending on turn of a steering wheel, to the corresponding cavity of the working cylinder in the case of the steering mechanism. Here liquid influences the piston and, thus, supports management process. At the same time the piston squeezes out liquid from an opposite cavity of the working cylinder via the returnable pipeline in the liquid tank.

Production of welding and leveling works with elements of a steering is not allowed. The self-stopped bolts and nuts, and also bolts and nuts having corrosion have to be replaced with the new.

The moments of an inhaling of threaded connections have to be maintained surely.

In a steering wheel the safety cushion of the driver is located. The safety cushion represents the developing air bag which is filled with air at a head-on collision of the car and thus protects the top part of a trunk and the driver's head. At a head-on collision of the corresponding force the control unit sends a signal to a safety cushion fuse. As a result of explosion gas which inflates a pillow during several milliseconds is formed. It is enough this time to damp movement of the top part of a trunk of the driver moving forward. Then within several seconds the safety cushion again develops since gases leave a pillow through the available openings.

The safety cushion consists of the sensor of collision, a fuse, the control unit of a safety cushion and the pillow. The signal on inflation of a safety cushion is developed by the control unit.

The car is equipped with a safety cushion of the driver and forward passenger, and also lateral safety cushions, safety cushions around the head and natyazhitel of seat belts. The locations of safety cushions are, as a rule, designated by inscriptions of "SRS Airbag".

The children's seat focused against the movement of the car excepting a special children's seat in combination with the device of automatic recognition of a children's seat is not allowed to have on a seat of the forward passenger.

For reasons of safety it is not allowed to carry out any works with the parts belonging to system of a safety cushion and natyazhitel of a seat belt.

Before work with security systems


  1. Disconnect a negative cable (-) of the battery at the switched-off ignition. It is previously necessary to remove a box of the filter of air of salon.

Before a detachment of a cable find out a protective code of the radio receiver if that is available, address to the Section Replacement of the Battery.

  1. Isolate the negative plug (-) of the battery to exclude casual contact.
  2. Establish wheels directly, and a steering wheel in average situation.
  3. Before removal (contact) of the block of a safety cushion remove an electrostatic charge. For this purpose quickly concern the lock of a door or a body.
  4. At connection of the battery in salon of the car there should not be people.

General measures of safety

Never establish components of an airbag of other car or other steering wheel. When replacing establish only new details.

Even after insignificant accident which did not lead to operation of a safety cushion, hand over system of a safety cushion and a natyazhitel of a belt on check on HUNDRED.

After operation of a safety cushion in a steering wheel surely replace a steering wheel, at operation of a lateral safety cushion replace a cover in facing of a door, at operation of a safety cushion of the forward passenger replace the dashboard.

The control unit of a safety cushion needs to be replaced surely after triple operation.

The safety cushion is allowed to be checked only for HUNDRED. By no means it is impossible to apply a control lamp, the voltmeter or an ohmmeter to check of a pillow.

The safety cushion elements which fell from height more than 0.5 m need to be replaced surely.

It is necessary to protect safety cushion elements from impact of a heat or fire. Do not subject safety cushion elements to influence of temperature above + 100 °C.

Protect a safety cushion from contact with water, greasing or oil. At hit of water, greasing or oil immediately wipe a pillow.

After removal of a safety cushion store it so that the soft party specified upward. At the return storage there is a danger of emission up at casual ignition of the generator of gas. Thereby there is a danger of traumatizing.

If in work the break becomes, it is impossible to leave a safety cushion without supervision.

It is not allowed to disassemble the safety cushion block. With malfunction it will be replaced completely. As the pillow contains explosive, it is necessary to store reliably it under supervision.

Before utilization of the car it is necessary to utilize safety cushion components.

When carrying out any works on the car with application of electric welding it is previously necessary to disunite the safety cushion control unit socket at the switched-off battery.