6.9.1. Dismantling and assembly

Dismantling

Fig. 6.27. Details of the wheel cylinder: 1 – piston assembled; 2 – cylinder case; 3 – persistent screw; 4 – persistent ring; 5 – crackers; 6 – spring; 7 – basic cup; 8 – sealant; 9 – piston; 10 – protective cap

Remove protective caps of 10 (fig. 6.27), then a vypressuyta from the cylinder case pistons 1 assembled with details of automatic control of a gap between brake shoes and a drum.
Install the piston assembled with the automatic device on adaptation 67.7820.9525 so that ledges of adaptation captured a head of the persistent screw 3. The special screw-driver, turning the piston 9, turn out the persistent screw 3 of the piston. Remove from the screw a sealing ring 8 with a basic cup 7, a spring 6 and crackers 5. Separate a persistent ring 4 and the persistent screw 3.
Assembly
You carry out assembly of the automatic device and the cylinder in the return sequence taking into account the following:
– before installation of details plentifully grease them with brake fluid;
– persistent screws of pistons tighten the moment of 3,9-6,9 N · m (0,4–0,7 kgfs · l);

Fig. 6.8. Wheel cylinder: 1 – block emphasis; 2 – protective cap; 3 – cylinder case; 4 – piston; 5 – sealant; 6 – basic plate; 7 – spring; 8 – crackers; 9 – persistent ring; 10 – persistent screw; 11 – union; And — a cut on a persistent ring

– the cut And (see fig. 6.8) on persistent rings has to be directed vertically up: the deviation from a vertical is allowed no more than 30 °. Such arrangement of a cut provides full removal of air from the drive of the brake mechanism of a wheel when pumping a brake;
– press pistons in the case of the cylinder by means of adaptation 67.7823.9532;
– the effort of a press fitting of the piston in the cylinder has to be not less than 345 N (35 kgfs); at smaller effort replace a persistent ring;
– at a piston press fitting in the cylinder it is necessary to sustain the size of 4,5-4,8 mm and 67 mm (as much as possible) (see fig. 6.8) for free landing of the brake drum;
– after assembly check movement of each piston in the cylinder case. They have to move easily within 1,25–1,65 mm. Establish the last into place protective caps 2.