BMW 3 Series E30

since 1983-1994 release

Repair and operation of the car


BMW E30
+ 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


621199f4


10.7. Blocks of drum brakes
GENERAL INFORMATION
Prevention

Blocks have to be replaced at the same time on both wheels. When replacing blocks it is also necessary to replace springs and elastic temperature regulators. Because of cyclic thermal loads of springs the last gradually lose the elastic properties and blocks begin to touch a drum that results in their accelerated wear.

Device of a back drum brake
1. Cap of a viewing opening
2. Brake board
3. Block
4. Slip
5. The top pulling together spring
6, 17. A bolt with an internal 6-faced head
7. Drum
8. Temperature regulator spring
9. The lower pulling together spring
10. A gap regulator level between blocks and drums
11. Spring of automatic adjustment
12. Lever of automatic adjustment
13. Wheel cylinder
14. Cup of a clamping spring of a block
15. The union for removal of air
16. Cap
18. Axis of a clamping spring

The most admissible diameter of a drum

If blocks do not change, then take measures to that. that not to mix them. Each block has to be established on the former place.

If the wheel cylinder leaks or is damaged, then replace it after removal of brake shoes, having disconnected a tube of a hydraulic actuator and having turned off bolts. The cylinder is not subject to repair though in the spare part to it remkomplekta are delivered.

PERFORMANCE ORDER
1. Block forward wheels, release bolts of fastening of back wheels. Lift a back part of the car and establish on supports. Remove back wheels and release the emergency brake.
2. Unscrew screws of fastening and remove a drum.
3. If the drum does not give in to removal, then dig the getting liquid between a disk and a nave and several minutes later remove a drum.
4. If the drum still does not give in to removal (on a drum the development fillet was formed), then reduce blocks having turned the thin screw-driver a regulator cogwheel.
5. Check existence of cracks, zadir, deep scratches and a vykrashivaniye on a drum. If defects are not eliminated with grinding with an emery paper, then a drum to a pereshlifuyta.
Prevention

Regrinding of a drum at each dismantling and check of a condition of a brake is recommended. Regrinding of a drum is not allowed if its internal diameter becomes more than the most admissible (it is specified on a drum).
6. Disconnect the lower returnable spring at first from a forward block, then from back, and remove a spring.
7. Disconnect the top returnable spring at first from a forward block, then from back, and remove a spring.
8. Remove a clamping spring of a forward block, then a clamping spring of a back block.
9. Remove a forward block with the lever of the regulator and a spring. These details should be put at assembly on a new block.
10. Remove the regulator assembled. Wipe the regulator and be convinced that the wheel is scrolled freely. Every time at installation of blocks is recommended to replace a thermospring (a spring bracket near a regulator wheel). Rotating a wheel expose the regulator in the situation corresponding to completely reduced blocks.
11. Disconnect a cable of the emergency brake from the lever of the drive and remove a back block
12. Installation is carried out upside-down taking into account the following.
13. Apply high-temperature lubricant on the rubbing sites of a board of a brake. Do not allow hit of lubricant on the rubbing surfaces of brake shoes or a drum.
14. Make sure that grooves of the regulator came into the corresponding grooves on the lever of the drive of blocks.
15. At installation of the regulator of blocks, at first install the lever on a block.
16. Then attach the lower end of a spring to the lever, and the top end to the corresponding opening in a forward block.
17. Upon termination of this stage of assembly the brake assembled has to look as it is shown in a picture. Now it is possible to start assembly of other brake.
18. Upon termination of install brake drums.
19. If changed wheel the cylinder, then pump over brakes (see subsection 10.16).
20. Press several times a brake pedal that the regulator worked, at the same time from drums clicks have to be listened.
21. Adjust the parking brake.
22. Establish wheels and wrap bolts. Lower the car and tighten bolts with the set moment. Check work of brakes before departure.