Wheel cylinders
Check the cleanliness of the working surfaces of the cylinder, pistons and thrust rings. Surfaces must be perfectly smooth and free of roughness to prevent fluid leakage and premature wear of seals and pistons. Eliminate defects on the cylinder mirror by lapping or grinding. However, an increase in the inner diameter of the cylinder is not allowed.
Check the condition of the stop screw 3 (rice. 6-20), springs 6, thrust cup 7 and crackers 5. If necessary, replace damaged parts with new ones.
Replace seals 8 with new ones. Check the condition of the protective caps 10 and replace them if necessary.
Pads
Carefully check the pads for damage or deformation.
Check the elasticity of the upper and lower coupling springs; replace them if necessary.
Springs should not have permanent deformations when stretched with a force of 350 N (35 kgf) lower springs and 420 N (42 kgf) - upper.
Check the cleanliness of the linings, if dirt or traces of grease are found, carefully clean the linings with a wire brush and rinse with mineral spirits, in addition, check if there is any leakage of grease inside the drum; troubleshoot. Replace the pads with new ones if the thickness of the pads has become less than 1.5-2 mm.
Brake drums
Inspect the brake drums. If there are deep grooves or excessive ovality on the working surface, bore the drums. Then grind on the machine with abrasive fine-grained bars. This will increase the durability of the linings and improve the uniformity and efficiency of braking.
The largest allowable increase in the nominal diameter of the drum (250 mm) after turning and grinding - 1 mm. The limits of this tolerance must be strictly observed, otherwise the strength of the drum is violated, as well as the effectiveness of braking due to a decrease in the rigidity of the drum.