Audi A4

since 1994 of release

Repair and car operation

A4 Audi
+ Running gear
+ Regular servicing
+ Engines
+ Turbo-supercharging
+ exhaust System
+ cooling System
+ Fuel tank and fuel pump
+ Air filter and absorption channels
+ injection System
- Coupling
   Coupling functioning
   Coupling actuating
   Coupling check
   Check of hydraulics of coupling
   The help at malfunctions
+ Transmission and main transfer
+ Suspension bracket of wheels and steering
+ Brakes
+ Wheels and tires
+ Electrotechnical equipment
+ ignition System
+ Lighting
+ Alarm equipment
+ Tools and devices
+ Heating and ventilation
+ body Details
+ Salon
Search of malfunctions
Technical characteristics

Check of hydraulics of coupling

In a bell of coupling of the dismantled engine knots of management of coupling are visible

1–the switching off lever (it is affected by force of the main cylinder of coupling);
2–Vyzhimny bearing;

3–entrance shaft of a transmission.

Over a coupling pedal (figure «1» designated the lever) (5) workers of the cylinder of coupling and both fixing bolts (3 and 4) are visible a rubber cuff. Figure «2» designated a lock collar of a sharnirny finger which should be taken out at dismantle.


    If coupling is switched off correctly, its hydraulic system in any case as it should be. But if it is switched off badly or the pedal fails without resistance, for certain air got to hydraulic system. Simple removal of air here will not help – it is necessary to find a place of leak and to repair it. Now you can remove air from system. You will find information on other causes of defect of coupling in the end of this chapter in the section Help at malfunctions. For the purpose of preventive check of hydraulic system of coupling look for traces of brake liquid on the working cylinder (above on a coupling pedal) and on the main cylinder (on a transmission). The cylinders of coupling moistened with oil are not tight and are subject to replacement. Though the origin of oily dirt on the main cylinder is defined hardly without thorough cleaning of this site.

 Council: The hydraulics of coupling receives the liquid from a tank with brake liquid, but at a leakage in this area danger does not threaten brake system. The branch pipe of a fence of liquid in hydraulic system of coupling is on a tank quite highly therefore for brakes always there is liquid enough.

Dismantle of the working cylinder of coupling


    Suck away as much as possible liquid from a broad tank (by means of a big medical syringe). Dismantle facing of a control panel at the left below (head Salon). Enclose under the working cylinder an old rag, disconnect submitting hose and let's flow down to the liquid rest in a rag. From an impellent compartment unscrew a delivery hose to the main cylinder. Unscrew two fixing bolts with internal shestigrannik at the working cylinder. Cast away back a lock collar of a sharnirny finger (connection of a pedal and the working cylinder), squeeze out a finger. Now it is possible to remove the cylinder. At installation of the new cylinder the rod pressing the piston of the working cylinder, should be adjusted so that the pedal of coupling was approximately on 10 mm above a brake pedal. Surely track: the returnable spring should wring out a pedal properly. Thus the pedal in position of rest should not adjoin above to the arm. Otherwise the piston of the working cylinder in position of rest cannot move to a back emphasis. For adjustment weaken a lock-nut on a press rod and turn press a rod to the left or to the right round its pivot-center. Then again tighten a lock-nut. Pump over hydraulic system of coupling.

 Council: The coupling pedal in Audi A4 is supplied with a so-called spring with the top dead point. It helps by pressing a pedal, but after removal of a foot returns it in a starting position. If the pedal does not come back back, air or a heavy course of a pedal or a spring got to hydraulic system.

Dismantle of the main cylinder of coupling


    Lift and fix the forward left side of the car. Unscrew from the main cylinder a delivery hydraulic hose – be careful, brake liquid thus follows. Substitute capacity. Weaken a fixing bolt on the cylinder, take out the main cylinder back from the transmission case. If it is necessary, help itself anticorrosive spray and the montirovochny lever. Slightly oil surfaces of the case of the new cylinder, grease with Mos2 paste a pusher. Insert the main cylinder into the case of a transmission and press it until it will be possible to screw up fixing bolts in a carving on a transmission (25 Nanometers). Pump over hydraulic system.

Air removal from hydraulic system of coupling

Who has no ordinary device for a workshop for air pumping, deletes air from hydraulic system of coupling the same as from brake – is almost faultless – the next way:


    Open a nipple for production of air on a brake of a forward wheel and a nipple on the main cylinder of coupling approximately on 1,5 turns everyone. Connect both nipples a hose. Now several times slowly and carefully press a brake pedal in order that hydraulic liquid from a brake of a forward wheel was wrung out through coupling hydraulics. Do not press on a pedal with force, differently the hose will break! Do not lose sight of liquid level in a broad tank. If in a broad tank air vials from hydraulic system of coupling do not arrive any more, both nipples are screwed up and the hose acts in film. Check level of brake liquid!