E30 series BMW 3

since 1983-1994 of release

Repair and car operation

+ 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-type brakes
   10.8. Main cylinder of brakes
   10.9. Vacuum amplifier of brakes
   10.10. Cable (ы) hand brake
   10.11. Adjustment of the hand brake
   10.12. Mechanism of the hand brake
   10.13. Brake pedal
   10.14. Switch of a signal of braking
   10.15. Hoses and lines of a hydraulic actuator of brakes
   10.16. Air removal from a hydraulic actuator of brakes
+ 11. Running gear
+ 12. Body
+ 13. Electric equipment
+ 14. Good advice

10.6. Brake disk



Disks of brakes (forward or back) should change or be ground in pair.


1. Release bolts of fastening of wheels, lift the car and establish on supports, remove a wheel and wrap three bolts in a disk. At work with a back brake disk turn on the hand brake.
2. Remove a support, take aside and fix, without disconnecting a hose. Unscrew bolts (shooters) and remove a support arm.
3. Check a disk surface on existence of cracks, wear and other damages. Existence of superficial damages and slight scratches is allowed. In the presence of deep задиров, it is necessary to replace a disk, or прошлифовать. If on a disk there are cracks, replace it.
4. Check both parties of a disk. If at inclusion of brakes strong vibration, that, probably is found, the disk is jarred on (palpation of a disk is very great). On cars with ABS system the vibration caused by a buckling, it is possible to take for normal work of ABS system (by pressing a pedal of a brake almost same vibration is felt, as at a faulty disk).
5. Check disk palpation, having established an indicator leg in 13 mm from edge of a disk and rotating a disk. If palpation exceeds norm, replace a disk or прошлифуйте.
6. The disk is recommended to be ground in any case, at least to remove roughnesses a small emery paper.
7. Disk polishing if its thickness becomes less limiting is not allowed. The limiting thickness of a disk is stamped on a part of a disk which fastens to a nave.

Admissible sizes and palpation of a disk (mm)

Admissible thickness of a disk after polishing
Maximum permissible thickness of a disk
Admissible unevenness of a disk on thickness
Admissible axial palpation:
  – 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, dig getting liquid between a disk and a nave and some minutes later remove a disk.
3. If the back disk does not give in to removal, reduce blocks, having turned a thin screw-driver a regulator cogwheel.


1. Carefully clear a disk, having removed traces of 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 hand brake (see subsection 10.12).
5. Before departure check work of brakes.