Pumping of hydraulic system of brakes. 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
9. Manual box of gear shifting (RKPP) and automatic transmission (AT)
10. Transmission line
11. Steering and suspension bracket
12. Brake system
12.1. General information
12.2. General information on anti-blocking brake system
12.3. Replacement of blocks of disk brake mechanisms
12.4. Removal, major maintenance and installation of a support of the disk brake mechanism
12.5. Survey, removal and installation of a brake disk
12.6. Replacement of boots of drums of brake mechanisms
12.7. Removal and installation of the main brake cylinder
12.8. Condition check, removal and installation of the vacuum amplifier of brakes
12.9. Description, removal and installation of the vacuum hydraulic booster of brake system
12.10. Replacement of a cable (cables) of a drive of the parking brake
12.11. Adjustment of the parking brake
12.12. Condition check, removal and installation of assembly of the parking brake
12.13. Adjustment of a pedal of a brake
12.14. Check and adjustment of the switch of a stoplight
12.15. Survey and replacement of brake lines and hoses of hydraulic system of brakes
12.16. Pumping of hydraulic system of brakes
12.17. Diagnostics of malfunctions of 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


12.16. Pumping of hydraulic system of brakes

When pumping brake system put on goggles. If liquid nevertheless gets to you to eyes, immediately wash out them water and address to the doctor. The majority of types of brake liquid are inflammable and can flare up at hit, for example, on hot details of the engine. Therefore with brake liquid it is necessary to address with not smaller care, than with gasoline. Adding or replacing brake liquid, always use its recommended type and take it from just open container. Never use repeatedly the liquid which has remained at pumping of system, and do not add in the tank liquid which a long time stood opened since it is potentially dangerous.

Brake liquid actively dissolves paint and plastic; if it was spilled, immediately wash away it a plentiful quantity of water.

Pumping of hydraulic system is necessary to remove all air which could get to it during removal or installation of hoses, brake lines, a support or the main cylinder.

If air got to system because of fall of level of brake liquid, or as a result of a detachment of brake tubes from the main cylinder, that, possibly, pumping of all four brake mechanisms is required.

If the brake tube was disconnected only at a wheel, then pump over only a support or the wheel cylinder.

If the brake tube was disconnected in the socket located between the main cylinder and one of brake mechanisms, it is necessary to pump over that part of system which is served by the disconnected tube.

When pumping all system entirely pump over it in such order: right back, left back, right forward, and at last, left forward brake mechanism.


  1. Remove residual vacuum from the vacuum amplifier, having pressed a brake pedal about 30 times at the switched-off engine. It also will remove pressure in system of anti-blocking of brakes where it is available.
  2. Uncover the tank of the main cylinder and fill the tank with brake liquid. Establish a cover.

During pumping procedure as it is possible check level of liquid more often and add liquid necessarily to prevent falling of its level below admissible when vials of air can get to the main cylinder.

  1. For carrying out procedure of pumping you need the assistant, the empty transparent plastic container and a piece of a transparent plastic or vinyl tube which can be got on pumping gates. It is possible to use also a special set for pumping «without the assistant». This set usually contains a tube or a bottle with the built-in unilateral valve - in this case the pedal will be normally squeezed out, but at its otpuskaniye air will back not get into system. When using set «without the assistant» follow the instructions enclosed to it; the same for sets for pumping under pressure. In any case you will need also a stock of more freshly brake liquid of the recommended type and a wrench for work with the pumping gate.
  2. Since the right back wheel, slightly release the pumping gate, then tighten it before situation when it is closed, but it can be easy and it is quickly open.
  1. Put on one end of a tube the gate of pumping and ship other its end in the container with brake liquid.
  1. Ask the assistant to squeeze out a brake pedal several times, and then strong to hold it squeezed out.

If the car is equipped with ABS system, let the assistant will squeeze out a pedal not less than 12 times.

  1. At the squeezed-out pedal of a brake open the pumping gate only so that the stream of liquid followed from a support or the wheel cylinder. Your assistant should squeeze out softly a brake pedal till the end and keep it in this situation. Watch, how vials of air leave through the shipped end of a tube. When through pair of seconds the stream of liquid will be slowed down, close the gate and ask the assistant to release a pedal.
  2. Repeat the actions described in the previous two paragraphs until vials of air their tube will not cease to leave, then tighten the gate of pumping and pass to a back left wheel, then to forward right, and at last, to forward left, in such order, repeating a touch the procedure. Do not forget to check more often liquid level in the tank of the main cylinder.

Never use old brake liquid. It contains moisture which spoils components of brake system.

  1. At the end of all procedure fill the main cylinder with liquid.
  2. Check operation of brake mechanisms. The squeezed-out pedal should be motionless, not sink down. If necessary repeat all process. Do not use the car if you are not sure of serviceability of its brake system.

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12.15. Survey and replacement of brake lines and hoses of hydraulic system of brakes
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12.17. Diagnostics of malfunctions of brake system