Pumping of hydraulic system of coupling. BMW the 5th E28/E34 series (from 1981 to 1993 of release)
Repair of BMW E28 and series E34 from 1981 to 1993
1. Cars of the BMW brand of 5-series
2. Engine
3. Cooling system
4. Power supply system
5. Ignition system
6. Control systems of the engine and decrease in toxicity of the fulfilled gases
7. System of production of the fulfilled gases
8. Coupling
8.1. General information
8.2. Description and coupling check
8.3. Removal and installation of the main cylinder of coupling
8.4. Adjustment of a pedal of coupling
8.5. Check of work and replacement of the switch of coupling (where it is provided)
8.6. Removal and installation of the executive cylinder of coupling
8.7. Pumping of hydraulic system of coupling
8.8. Removal, survey and installation of components of coupling
8.9. Diagnostics of malfunctions of coupling
9. Manual box of gear shifting (RKPP) and automatic transmission (AT)
10. Transmission line
11. Steering and suspension bracket
12. Brake system
13. Body
14. Control body sizes
15. Heater and air conditioner
16. System of onboard electric equipment
17. Routine maintenance of the car
18. Size table and adjusting data
19. Schematic electric circuits
20. Governing bodies and operation receptions
21. System of onboard diagnostics - a principle of functioning and codes of malfunctions


8.7. Pumping of hydraulic system of coupling

Hydraulic liquid is poisonous. It also well dissolves paint. Be careful, do not allow liquid hit on open sites of a body or in eyes. Hold near at hand rags for collecting the poured liquid, and in case of hit it on the painted surfaces immediately wash away liquid plentiful amount of cold water.

Air hit in hydraulic system can lead to that coupling will work not completely when squeezing pedal. Air can get to system during removal of any of its components and also if liquid level falls in the tank of the main cylinder below the admissible. Besides, sometimes air gets to system through openings, too small liquids for leak. In this case major maintenance is necessary for system.

For system pumping you will need the assistant to press a coupling pedal, the transparent plastic container and the piece of a flexible transparent tube suitable on diameter to the gate of pumping. It is possible to use also a set for pumping without the assistant. It usually consists of a tube or a bottle with the built-in unilateral valve - in this case at a pedal otpuskaniye air will back not arrive in system. If you use such set, follow instructions enclosed to it. In both cases you will need a quantity of more freshly brake liquid of recommended type and a special key for the pumping gate.


  1. Check liquid level in the tank. If necessary make having added to finish level to «full» or «MAX» mark. Use only liquid of the recommended type and do not mix different types of liquids. Never use liquid of their container which long time stood open since it absorbed moisture from air that made it unsuitable to use. In the course of pumping you should check often liquid level in the tank. If it falls too low, air will get to system.
  2. Cock the parking brake. To Poddomkratta a front of the car and reliably establish it on axial support.
  3. Remove a cap from the pumping gate on the executive cylinder (see an illustration).
  4. Put on the end of a plastic tube the union of the gate of pumping. Fill the container approximately on one third with pure liquid, then ship in it other end of a tube.
  5. Slightly release the pumping gate, then tighten it so that it needed to be released.
  6. Ask the assistant to squeeze out a coupling pedal several times and to hold her in completely squeezed out situation.
  7. At the squeezed-out pedal open the pumping gate approximately on a half of turn. When liquid will stop to follow through a tube in the container, tighten the gate. Once again squeeze out a pedal, and holding it squeezed out, instantly release the gate. Do not release a pedal at the open gate of pumping.
  8. Repeat this procedure until through a tube will not cease to pass air vials. Do not forget to check constantly liquid level in the tank.
  9. Tighten completely the pumping gate, lift the receiver and establish a gate cap.
  10. Once again check liquid level the tank to make sure that it reaches the top point, then make a trial trip on the car to check coupling work.

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8.8. Removal, survey and installation of components of coupling