6.9.2. Check of details

Wheel cylinders
Check purity of working surfaces of the cylinder, pistons and persistent rings. Surfaces have to be absolutely smooth that there was no leak of liquid and premature wear of sealants and pistons. Eliminate defects on a mirror of the cylinder with grinding in or grinding. However at the same time increase in internal diameter of the cylinder is not allowed.

Детали колесного цилиндра
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

Check a condition of the persistent screw 3 (see fig. 6.27), springs 6, a basic cup 7 and crackers 5. If necessary replace the damaged details new.
Replace a sealant 8 new. Check a condition of protective caps 10 and if necessary replace them.
Attentively check whether is not present on blocks of damages or deformations.
Check elasticity of the coupling and directing springs of blocks, if necessary replace them new. Coupling springs should not have residual deformations at stretching of the lower springs by effort of 137,2 N (14 kgfs) and top – 294 N (30 kgfs).
Check purity of slips if dirt or traces of lubricant are found, carefully clear slips a metal brush and wash out white spirit, besides, check whether there is no leak of lubricant in a drum; eliminate the found malfunctions.
Replace blocks new if thickness of slips became less than 1,5 mm. You make replacement at the same time on both brake mechanisms, that is both couples of blocks.
Brake drums
Examine brake drums. If on a working surface there are deep risks or excessive ovality, then chisel drums on the machine. Then also on the machine abrasive fine-grained whetstones to a proshlifuyta drums. It increases durability of slips and improves uniformity and efficiency of braking.
Increase in diameter of a drum (200 mm) after boring and grinding is allowed to 201 mm. Maximum permissible diameter of a drum is 201,5 mm. These requirements have to be observed strictly, otherwise the drum durability, and also efficiency of braking is broken.