9.9.3. Replacement of brake shoes of the back brake mechanism

Replace blocks in the following cases:
– thickness of frictional slips of less admissible (1,5–2 mm);
– the surface of slips is greasy;
– the frictional slip is unsteadily connected to the basis;
– on slips deep furrows and chips appeared.

Preventions
Do not apply gasoline, diesel fuel or any other mineral solvents to cleaning of brakes.
Replace blocks at the same time in brake mechanisms of both back wheels.

It will be required to you: keys "on 8", "on 19", the screw-driver with a flat edge.
1. Remove a wheel (see. "Replacement of a wheel").
2. If the level of brake fluid is in a tank of the main brake cylinder on a tag of "MAX" or approaches her, pump out a part of liquid from a tank, otherwise when replacing blocks it can be splashed out.
3. Remove the brake drum (see. "Replacement of the brake drum").
4. Remove a protective cap …
5. … and, оперев the screw-driver on the brake cylinder, bring a coupling spring out of gearing with a block.

Prevention
During the work with the screw-driver be careful. We recommend to use special pincers for removal of coupling springs.

6. Part blocks …
7. … also remove a coupling spring.
8. Holding a core of a clamping spring, press the top cup, turn it on 90 ° …
9. … also remove the top cup, a clamping spring and the lower cup.
10. Take a core of a clamping spring.

Prevention
After removal of cores of clamping springs fix pistons of the working cylinder in any available way (for example, pull together with a rubber plait or connect by a wire), otherwise pistons can be pushed out from the cylinder by an expansion spring and from a hydraulic system brake fluid will flow out.

11. Holding a basic finger from a provorachivaniye, turn off a nut of its fastening …
12. … take a finger …
13. … also remove a block and the plug of a basic finger.
14. Similarly remove the second block. At the same time the plate of basic fingers will be removed.

Fig. 9.3. Details of the brake mechanism of a back wheel (details of the brake mechanism on the left side are shown): 1 – basic finger; 2 – plug of a basic finger; 3 – core of a clamping spring; 4 – lower cup of a clamping spring; 5 – clamping spring; 6 – top cup of a clamping spring; 7 – brake shoe; 8 – coupling spring; 9 – plate of basic fingers

15. Clear of pollution and examine details of the brake mechanism (fig. 9.3). Replace the deformed or strongly corroded details. Replace the springs which are strongly stretched, lost elasticity and bent.
16. About a brake board apply refractory lubricant for brake mechanisms on places of friction of brake shoes.
17. Exempt pistons of the working cylinder from the fixing adaptation, sliding passatizha squeeze pistons of the working cylinder and establish brake shoes as it should be, the return to removal.

Prevention
Consider that at an utaplivaniye of pistons in the cylinder the level of brake fluid in a tank of the main brake cylinder increases. If necessary pump out liquid.

18. Install the brake drum (see. "Replacement of the brake drum").
19. Establish into place a wheel and adjust a gap between brake shoes and a drum (see. "Adjustment of brake mechanisms of back wheels").
20. Similarly replace brake shoes of the brake mechanism of other wheel.