Replacement of protective cuffs of a support and the piston of the brake mechanism

If there are defective or carelessly mounted protective collars, dirt and moisture will enter the hydraulic cylinder. Over time, the sliding pistons then begin to slowly but surely rust. Consequences: high wear of brake linings and discs, uneven braking action.

PROCEDURE

Dismantle or mount the brake linings as described above and... ... first check the free play of the linings in the shafts. If necessary, clean the shafts with a stiff wire brush or medium slotted screwdriver and blow with compressed air. Take care not to damage the protective cuffs or loosen their fit. Before refitting the brake linings, coat all contact surfaces with high temperature copper paste. It goes without saying that the calipers must also have free play. If not, clean and lubricate the sliding surfaces as above with high temperature copper paste.

Brake piston check

PROCEDURE

Before checking pistons for «patency», install a clamp with a wooden block on the caliper as an emphasis. It will protect the piston from damage - it will no longer be able to slip out of the cylinder. The opposite caliper must of course be fully assembled. Ask the assistant now to carefully press the brake pedal. If the piston is clamped, then the assistant «pumps» brake pedal until it appears outside. Place the mounting lever between the piston and the disc beforehand. As soon as the piston appears, send it back into the cylinder using the lever. Repeat this procedure until the piston slides easily in the cylinder. Attention: if these actions did not lead to anything, then it is better to send the caliper for repair to the workshop.

Replacing the protective cuff

PROCEDURE

Use a curved weld wire or a small curved screwdriver to pry the old seal off the brake caliper and piston. Be careful not to scratch the surfaces of the piston or cylinder. See if brake fluid is leaking from the cylinder. In this situation, it is better to send a caliper «for treatment» to the workshop. Clean the sealing surfaces with denatured alcohol or clean brake fluid. Preserve cleaned surfaces with brake cylinder paste before fitting new seals (Ate, Bosch, Girliling). Gently press the new cuff against the sealing surfaces, make sure that the cuffs fit snugly and only after that... ... push the piston all the way back into the cylinder. Install the brake pads as described above. Check the brake fluid level in the compensation tank. Before you put the car on wheels, check the entire brake system for leaks. And only then complete the installation in reverse order.