S-class W202 Mercedes

1993-2000 of release

Repair and car operation

W202 Mercedes
+ 1.2. General information
+ 2. Maintenance
+ 3. Engines
+ 4. Greasing system
+ 5. Cooling system
+ 6. Heating, ventilation
+ 7. Ignition system
+ 8. Fuel system
+ 9. Transmission
+ 10. Running gear
+ 11. Steering
- 12. Brake system
   12.2. Anti-blocking system – ABS
   12.3. The additional equipment – ASR system
   12.4. Specifications of brake system
   12.5. Overlays of forward brake shoes
   + 12.6. Overlays of back disk brakes
   12.7. Support
   12.8. Forward brake disk
   12.9. Back brake disk
   12.10. Brake liquid
   12.11. Air removal from brake system
   12.12. Brake pipelines / hoses
   12.13. Replacement of brake highways
   12.14. Brake shoes of the parking brake
   12.15. Adjustment of the parking brake
   12.16. Stoplight switch
   12.17. Diagnostics of malfunctions of brakes
   + 12.18. Wheels and tires
+ 13. Body
+ 14. Electric equipment
+ 14.2. Electroschemes

b47c026d b47c026d

12. Brake system

12.1. Introduction


Brake system with ABS and ASR

1. Sensor of turns
2. Hydraulics block
3. Forward brake mechanism
4. Main brake cylinder
5. Amplifier of brakes
6. Cable of the parking brake
7. Lay brake drums
8. Back brake disks

The hydraulic brake system with a foot drive consists of the main brake cylinder, the hydraulic booster of brakes and disk brakes of lobbies and back wheels. The brake system has two contours. One of contours covers the forward wheels, the second – back. At failure of one of contours, for example, owing to a leakage, the car can be braked by means of only the second contour. Pressure in both contours is created in the dual main brake cylinder by pressing a brake pedal.

The tank with brake liquid is over the main brake cylinder and provides with brake liquid all system.

The hydraulic booster of brakes accumulates a part of depression of absorption received by means of the engine. As in a diesel engine it is not formed absorption depression sufficiently, models with a diesel engine have the special pump of depression for brake system. In this case the effort by means of depression is transferred to brakes via the corresponding valve.

Forward disk brakes are equipped with the disk mechanism with a floating bracket. In this case one piston is necessary only to press both brake slips to a brake disk. On the back bridge there are brake mechanisms with the fixed bracket which provide demanded delay. Pressing of brake slips in case of the mechanism with the fixed brackets needs two pistons.

The parking brake is given by means of a cable and influences only back wheels. As disk brakes not so well approach as lay, on back wheels two brake drums which have been built in brake disks are in addition placed. Brake drums are involved only for parking.

When cleaning a brake mechanism the dust of wear of slips which is unhealthy flies. Therefore when cleaning brakes watch to inhaling products of wear of brakes. Brake slips are a component "Permissions to car operation in these conditions", besides, they differ depending on model. It is recommended to apply only firm brake slips.

Instruction: after installation of new slips they should be earned extra. During a running in (about 200 km) avoid without necessity of sharp braking.

Work on brake system demands careful purity and exact observance of technology. If experience is absent, address in a workshop.


If when braking, especially on turns, the various course of a pedal is felt, it is necessary to check brake disks on lateral palpation on external diameter. Too big lateral palpation can be caused raised lyufty bearings. Therefore before check this люфт and if necessary establish it. If after that it is not felt sufficient improvement, replace a brake disk.