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

10.6. Brake disk



Disks of brakes (forward or back) have to change or be ground in couple.


1. Release bolts of fastening of wheels, lift the car and establish on supports, remove a wheel and wrap three bolts in a disk. During the work with a back brake disk turn on the emergency brake.
2. Remove a support, take aside and fix, without disconnecting a hose. Turn off bolts (shooters) and remove a support arm.
3. Check a disk surface for existence of cracks, wear and other damages. Existence of superficial damages and slight scratches is allowed. In the presence of deep zadir, the disk needs to be replaced, or to proshlifovat. If on a disk there are cracks, then replace it.
4. Check both parties of a disk. If at inclusion of brakes strong vibration, then, perhaps is found, the disk is jarred on (the beating of a disk is very big). On cars with ABS system the vibration caused by a buckling can be taken for normal work of ABS system (when pressing a pedal of a brake almost same vibration is felt, as at a faulty disk).
5. Check a disk beating, having established an indicator leg in 13 mm from edge of a disk and rotating a disk. If the beating exceeds norm, then replace a disk or a proshlifuyta.
6. The disk is recommended to be ground anyway, at least to remove roughnesses a small emery paper.
7. Grinding of a disk is not allowed if its thickness becomes less limit. Extreme thickness of a disk is stamped on a part of a disk which fastens to a nave.

Admissible sizes and beating of a disk (mm)

Admissible thickness of a disk after grinding
Maximum permissible thickness of a disk
Admissible unevenness of a disk on thickness
Admissible axial beating:
  – The disk is removed
  – The disk is established


1. Unscrew the screw and remove a disk from a nave.
2. If the disk does not give in to removal, then dig the getting liquid between a disk and a nave and several minutes later remove a disk.
3. If the back disk does not give in to removal, then reduce blocks, having turned the thin screw-driver a regulator cogwheel.


1. Carefully clear a disk, having removed traces of the getting liquid. Establish a disk on a nave and tighten the screw.
2. Establish a support arm (if it is removed), brake shoes and a support. Tighten bolts and screws of all connections with the set moments.
3. Establish a wheel, lower the car. Press several times a brake pedal.
4. If necessary adjust blocks of the emergency brake (see subsection 10.12).
5. Before departure check work of brakes.