BMW 3 Series E30

since 1983-1994 release

Repair and operation of the car

+ 1. Maintenance instruction
+ 2. Maintenance
+ 3. Engine
+ 4. Cooling system
+ 5. Heating and ventilation
+ 6. Fuel system
+ 7. Exhaust system
+ 8. Transmissions
+ 9. Coupling
- 10. Brake system
   10.2. Specifications
   10.3. Anti-blocking system (ABS)
   10.4. Blocks of disk brakes
   10.5. Support of a disk brake
   10.6. Brake disk
   10.7. Blocks of drum brakes
   10.8. Main cylinder of brakes
   10.9. Vacuum amplifier of brakes
   10:10. Cable(s) of the emergency brake
   10:11. Adjustment of the emergency brake
   10:12. Mechanism of the emergency brake
   10:13. Brake pedal
   10:14. Braking signal switch
   10:15. Hoses and lines of a hydraulic actuator of brakes
   10:16. Removal of air from a hydraulic actuator of brakes
+ 11. Running gear
+ 12. Body
+ 13. Electric equipment
+ 14. Useful tips

Максимус официальный сайт калининград адреса магазинов maximus в калининграде. 621199f4

10. Brake system

10.1. Introduction


The scheme of double-circuit brakes (the option with disk lobbies and back brakes is shown) and the drive of the emergency brake

1. Cables of the emergency brake
2. Support of a back brake
3. Disk of a back brake
4. Tube of the highway of a hydraulic actuator
5. Pedal
6. Main cylinder of brakes
7. Support of a forward brake
8. Disk of a forward brake
9. Nutritious tank of brakes and hydraulic actuator of coupling
10. Vacuum amplifier
11. Lever of the emergency brake

Device of a forward brake

1. Bolt
2. The union for removal of air
3, 17. Support axis
4, 7. Cover
5. Piston
6. Cover
8. Sensor of wear of brake shoes
9. Block
10. Screw of fastening of a disk
11. Continuous disk
12. The ventilated disk
13, 14, 18. Bolt
15. Support arm
16. Cylinder sealant
19. Support

All cars are completed with forward disk brakes and also back disk or drum brakes. On all cars forward and back brakes are self-regulating. On some cars of late release the anti-blocking brake system (ABS system) is installed.

Hydraulic system

The hydraulic system consists of two separate contours. For each of contours the separate section is provided in the main brake cylinder. If in one of contours there is a leak or other malfunction, then other contour remains to workers.

Vacuum amplifier

The vacuum amplifier of brakes uses vacuum in a collector of the engine and atmospheric pressure to provide increase in effort of braking, it is established on a partition in a motor compartment

Emergency brake

The emergency brake has the drive on back wheels by means of the cable and the lever located in the central section of salon. The emergency brake is a part of a back drum brake, the gap between blocks and drums is regulated automatically. On cars with back disk brakes the lever of the emergency brake puts two blocks located in the central part of a brake disk in action. The gap between blocks and drums is regulated manually.

System of the prevention of wear of brake shoes

If blocks are worn-out to such an extent that they need to be replaced, then the red precautionary lamp on the dashboard lights up. If blocks are not replaced, then it can lead to damage of a disk.

On some cars the additional control lamp of wear of blocks which lights up only at the pressed brake pedal is established, warning, thus about fast replacement of blocks.

The sensor of wear is attached to brake shoes. The sensor settles down on the left forward wheel, on some models there is one more sensor on the right back wheel. The sensor of wear provides short circuit of contacts at wear of a block to some set limit. Fire of a lamp of wear of blocks means that the disk of a brake erases insulating covering of the sensor. When replacing blocks always check the sensor(s). When replacing blocks after fire of an alarm lamp, it is necessary to replace as well the sensor(s).


Upon completion of any works with units of the brake system always check efficiency of braking of the car. Check of brakes should be carried out on the flat, pure, dry road with low-heavy traffic.

Check of brakes should be carried out at various speeds, by weak and sharp pressing a brake pedal. The car has to stop without having changed the direction of the movement. Do not allow the movement by a skid since it leads to reduction of efficiency of braking and decrease in stability of the car.

Efficiency of braking is also influenced by a condition of tires and the angles of installation of wheels.