Mercedes C-Class

W203 since 2000 of release

Repair and operation of the car


Mercedes-Benz
+ Mercedes-Benz cars of class C (W-203)
+ Operation manual
+ Routine maintenance
+ Engine
+ Cooling system and heating
+ Power supply system and release
+ Engine electric equipment
+ Manual transmission
+ Automatic transmission
+ Coupling and power shafts
- Brake system
   Specifications
   Replacement of blocks of a forward disk brake
   Removal and installation of a forward support
   Replacement of back brake shoes
   Removal and installation of a back support
   Removal and installation of a brake disk
   Check of a brake disk
   Dual main brake cylinder
   Replacement of brake shoes of the parking brake
   Removal and installation of a cable of the drive of the parking brake
   Removal and installation of the switch of a stoplight
   Removal of air from the brake system
   Removal and installation of a brake hose
   Check of the amplifier of a brake
+ Suspension bracket and steering
+ Body
+ Onboard electric equipment


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Removal of air from the brake system

Rules of the treatment of brake fluid

The remark on security measures

Brake fluid is poisonous. Do not soak up it a mouth or through a hose at all. You store brake fluid only in bottles, casual access to which is excluded.

At the treatment of brake fluid it is necessary to follow the following rules:

Brake fluid is aggressive and for this reason should not come into contact with a paint and varnish covering of the car. If it occurred, immediately wipe the place of contact and wash out water.

Brake fluid is hygroscopic, i.e. it absorbs moisture from air. You store brake fluid only in the closed vessels.

Take measures to that children incidentally could not drink brake fluid.


Brake fluid which was already used in the brake system of the car once should not be applied. During removal of air of their brake system also apply only new liquid.

Specification of brake fluid: DOT4.

Level of brake fluid has to be in the tank between the marks MAX and MIN.


Brake fluid should not come into contact with mineral oil. Even insignificant traces of mineral oil do brake fluid not suitable for the use or lead to failures of the brake system. Cuffs and laying of the brake system are damaged at contact with mineral oils. Do not apply to cleaning of a rag, with traces of mineral oils.

To washing and cleaning of brake cylinders, hoses and pipelines apply only new brake fluid.

Replace brake fluid each 2 years, whenever possible after cold season.

Brake fluid represents dangerous liquid which cannot be poured out or out at all somewhere with household waste. The local administration has to provide information on the closest places of delivery of brake fluid.


Removal of air from the brake system

After carrying out repair of the brake system during which its opening was made air can get to system. In this case air needs to be removed from system. A sign of existence in pipelines of system of air is the brake pedal pliability when pressing it. In this case it is necessary to eliminate leakage and to remove air from system.

On HUNDRED brake system it is, as a rule, filled with liquid, and air from it is removed by means of the special device. Remark: When using of the specified adaptation pressure of filling of system should not exceed 1 atm. This operation can be performed as well without the specified device. In this case air from the brake system is removed by kachatelny movements of a pedal of a brake what requires the help of the assistant.

If air got into any separate brake cylinder, it is necessary to delete air from all brake system and by that from each wheel cylinder. If only one support, as a rule, is replaced or under repair it is sufficient to remove air from the corresponding brake cylinder.

The remark on security measures

If one of cameras of the tank of brake fluid (for example, with leakage in the brake system is completely emptied or if during removal of air forgot to add liquid in the tank), in system air which gets to the pump ABS is sucked in. Air from the brake system in this case has to be removed on HUNDRED with use of the special device.

Sequence of removal of air: back right brake, back left brake, forward right and forward left brake and working cylinder of coupling.

Carefully open gates for removal of air so that not to break them. It is recommended to spray a gate carving approximately in 2 hours prior to removal of air rust solvent. If the valve does not turn away, recommended to perform this operation on HUNDRED.

During removal of air periodically you watch the liquid tank. Level of liquid should not fall too low, otherwise via the tank air can get to system. Surely fill system only with new brake fluid.


Turn off a cover of the tank of brake fluid and put it aside. Fill system with liquid to the mark MAX.

Mark with paint the provision of wheels concerning naves. It will allow to establish at assembly the balanced wheels in their former situation. Weaken bolts of fastening of a wheel before a car poddomkrachivaniye. Lift the car, put it on supports and remove wheels.

Security measures

Lifting operation and installations of the car on supports is connected with danger! Therefore before carrying out operation study Poddomkrachivaniye's Section and towage of Introduction to the management.

 PERFORMANCE ORDER

1. Remove a dustproof cap (1) from the gate for removal of air (2) on the wheel cylinder.

2. Clear the gate, put on it a pure hose. Lower other end of a hose in the bottle filled on a half with brake fluid. Apply a special key (HAZET 1968-N) to an otvorachivaniye of the gate.

3. Establish or hold a bottle for liquid at the height not less than 30 cm over the union for removal of air. Thus the possibility of hit of air in the brake system through an union carving is excluded.

4. Ask the assistant "to shake" a brake pedal until in system pressure does not rise. It will be felt on brake pedal resistance.
5. After achievement of necessary pressure completely press through a pedal and you hold it with a leg.
6. Unscrew a cap key the gate on the wheel cylinder approximately half way.
7. When liquid begins to come to a bottle, watch that the end of a hose always was in a bottle lower than the level of liquid.
8. As soon as pressure of liquid falls, close the gate.
9. Repeat process of swing of a pedal until pressure is created. Squeeze out a pedal, leave a leg foot on a pedal, open the gate of removal of air so that pressure fell down, and then close the gate.
10. Repeat process of removal of air of the wheel cylinder until in the liquid coming to a bottle there are no vials of air.
11. Carefully tighten the gate for removal of air the moment of 7 Nanometers.
12. After completion of operation remove a hose from the union for removal of air and put on a protective cap the gate.
13. Similarly, observing the sequence stated above, remove air from other brakes.
14. Establish into place wheels so that the marks put at removal coincided. Previously grease with a thin layer of bearing lubricant the aligning wheel disk belt on a nave. Do not grease bolts of fastening of wheels. Replace rusty bolts. Wrap bolts. Lower the car on wheels and tighten bolts cross-wise the moment of 110 Nanometers.
15. After completion of process of removal of air fill the tank with brake fluid to the mark MAX and screw a cover.

Carry out reliability control:

· Whether brake hoses are fixed?
· Whether the brake hose is fixed in the holder?
· Whether unions for removal of air are tightened?
· Whether enough brake fluid is filled in?
· On the working engine check tightness. For this purpose press a brake pedal by effort of 200 - 300 N (20 – 30 kg) during 10 pages. The pedal should not weaken. Check all accessions for tightness.
16. Check operation of the brake system on the road with not heavy traffic. For this purpose it is necessary to carry out, at least, one strong braking with ABS action use (it is felt on a brake pedal pulsation).

You watch closely the transport following you.

Brake fluid represents dangerous liquid which cannot be poured out or out at all somewhere with household waste. The local administration has to provide information on the closest places of delivery of brake fluid.