Remove the piston from the caliper by supplying low-pressure air to the brake cylinder through the hole for connecting the brake hose, installing a wooden block instead of the brake pads. The air pressure should be just enough to push the piston out of the hole. A piston that pops out under a lot of force, even if the block of wood is left in place, can be damaged.
Pic. 14.35. Elements of the rear disc brake caliper: 1 - air removal fitting; 2 - rubber cap; 3 - top dust seal; 4 - finger; 5 - clamp; 6, 16 - dust seals; 7 - piston; 8 - piston seal; 9 - retaining ring; 10 - emphasis; 11 - sealing ring; 12 - self-adjusting parking brake spindle; 13 - bottom dust seal; 14 - spindle lever; 15 - return spring; 17 - cap; 18 - parking brake cable mounting bracket
Remove clip and dust seal from piston (pic. 14.35).
Remove the piston seal from the caliper cylinder.
Using pliers with thin jaws, remove the retaining ring from the bottom of the caliper cylinder.
Remove the parking brake self-adjusting spindle, o-ring, stop and pin.
Remove dust seals and guide pin covers.
Turn out bolts of fastening of an arm of a cover of a cable of a parking brake.
Disconnect the return spring, remove the spindle arm and oil seal.
If necessary, remove the bleed screw.
Clean all elements and check them for wear and damage. In particular, check the surfaces of the piston and caliper cylinder, as well as the needle bearing of the adjusting spindle.
Purchase a seal repair kit, other necessary spare parts. Repairs will require red, white, and orange greases: red grease for the piston seal, white grease for the adjusting spindle o-ring, and orange grease for the dust seals, needle bearing, spindle, and guide pins.
Assembly is carried out in the reverse order of disassembly; at the same time, check that the locking pins fit into the holes in the caliper body.