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10.7. Blocks of drum brakes


Details of back drum brakes

1. Cap
2. Piston
3. Spring
4. The union for removal of air
5. Piston sealant
6. External sealant of the piston
7. Wheel cylinder
8. Lever of the drive of a block of parking
brakes
9. Lever of automatic adjustment
gap between blocks and drums
10. Lock ring
11. Spring of the lever of automatic adjustment
12. Lower coupling spring
13. Clamping spring of a block
14. Cups
15. Forward block
16. Axis
17. Brake board
18. Cap of a viewing opening
19. Cutting washer
20. Regulator
21. Back block

Replacement
Prevention

Blocks change only in a set on one axis.


Together with blocks also coupling springs which, being exposed to periodic thermal loadings, gradually lose elasticity change and do not provide sufficient withdrawal of a block from a drum. As a result the drum touches blocks, causing their premature wear.

PERFORMANCE ORDER
1. Release nuts of wheels, lift a back part of the car. Remove wheels.
2. Release the parking brake.
3. Remove a wheel. If blocks do not change, then mark them so that at assembly to establish on former places.
4. Designate provision of a drum on a nave that at assembly not to break balancing.

Prevention
If the drum does not give in to removal, then reduce blocks. For this purpose get a cap from a board of a brake and rotate a gear flywheel of the regulator the screw-driver, having taken away the lever from a gear flywheel other thin screw-driver.

5. Clear brake details.
6. Remove a coupling spring.
7. Remove clamping springs of blocks, having pressed a cup and having turned on 90 °.
8. Remove a forward block, unhook the lower spring.
9. Remove a clamping spring of a back block.
10. Remove a back block and the regulator from a brake board.
11. Get flat-nose pliers a cable of the parking brake from the lever.
12. Get a regulator lever spring.
13. Unhook a returnable spring from a block and remove the regulator.
14. Remove a cutting washer and remove levers of the drive of the parking brake and the regulator.
15. Install levers of the drive of the parking brake and the regulator on a new block, establish a cutting washer and squeeze it.
16. Grease the rubbing surfaces of the regulator with refractory lubricant. The regulator wells up after installation of the reel on new blocks.
17. Install the regulator on a back block (the fork of the regulator has to come into a groove on a block) and hook on a spring for an opening in a block.
18. Dress a regulator spring.
19. Grease places of a prileganiye of blocks with refractory lubricant.
20. Get a spring of a cable of the parking brake, and, holding it flat-nose pliers, dress a cable on the bent part of the lever of the drive of a block.
21. Establish a back block, dress a cup, a clamping spring and fix by an external cup, having turned a cup on an axis on a corner 90 °.
22. Hook on the lower coupling spring for eyes of blocks, establish a forward block, a clamping spring and cups.
23. Give the block drive lever forward and be convinced that the spring of the regulator was not unhooked from a back block.
24. Check reliability of fastening of blocks of a back brake, having shaken them here and there and on themselves.
25. The screw-driver pull the top coupling spring and hook on it for an opening in a block.
26. Before installation clear a drum and check a condition of a surface. Check ovality of a drum, at strong damages pierce a drum, small roughnesses are ground by a skin.
Prevention
When replacing blocks the drum is recommended to be proshlifovat, irrespective of its state to remove any possible ovality. If after a pro-point the internal diameter of a drum appears more limit, replace a drum. Extreme diameter of a drum is cast on its internal surface.

27. Install the reel.
28. Establish a wheel and lower the car, hold on wheel nuts.
29. Make several braking, moving forward also a backing, working with the parking brake, establish a gap between blocks and drums.
30. Before departure check work of brakes.