Pic. 6.38. Rear Disc Brake Components: 1 - guide pin; 2 - guide pin; 3 - bushing; 4 - caliper bracket (with brake pads); 5 - anther; 6 – anther collar; 7 - piston boot; 8 - piston; 9 - piston sealing ring; 10 - support; 11 - brake shoe; 12 - brake shoe; 13 - gasket; 14 - latch
The components of the rear disc brake are shown in fig. 6.38.
Pic. 6.39. Map of lubrication points
Disassembly
Remove the wheel.
Pic. 6.40. Removing the brake pads
Remove the guide pins, lift up the caliper assembly and remove the pad assembly (pic. 6.40).
When disassembling the rear disc brakes, disassemble on both sides of the vehicle (left and right).
Removing the piston seal and piston.
Pic. 6.41. Piston removal
Wrap the caliper with a cloth. Apply compressed air to the brake hose opening to remove the piston and piston boot. Remove the piston seal and piston (pic. 6.41).
Attention! Apply compressed air gradually.
Pic. 6.42. Removing the piston seal
Remove the piston o-ring with your finger (pic. 6.42).
Attention! To prevent damage to the inner surface of the working brake cylinder, do not use a flathead screwdriver or other tool.
Wash piston and cylinder surfaces with trichlorethylene, alcohol, or recommended brake fluid.
Used brake fluid: DOT3 or DOT4.
Examination
Check the brake cylinder for signs of wear, damage and rust.
Check the surface of the brake cylinder piston for signs of wear, damage and rust.
Check the caliper bracket and bushing for signs of wear.
Check the brake pad linings for damage or oil, and the metal backings of the pads for damage.
Pic. 6.43. Scheme for checking brake pads
Check the brake pads for excessive wear and oiling of the friction surface. Replace brake pads if necessary (pic. 6.43).
Note. If the brake shoe and lining assembly needs to be replaced, replace the entire set of brake shoes on the left and right side of the vehicle.
Brake lining thickness (limit value): 2 mm
Check the piston and its inner surface for signs of wear, damage and rust.
Replace damaged parts if necessary.
Check the piston o-ring, piston boot and guide pin boots for wear and damage.
Assembly
When disassembling the caliper, use only a new piston o-ring and piston boot.
Apply the recommended fluid to the sealing surfaces of the piston o-ring and piston. Install the piston o-ring into the groove of the caliper bore, being careful not to twist the o-ring.
Install the piston boot on the piston.
Pic. 6.44. Installing the piston in the caliper
Install the piston and piston boot into the caliper (pic. 6.44). Insert the boot clamp into the caliper and check the fit of the boot in the groove around the circumference of the piston.
Apply the recommended oil to the inside surface of the guide pin boot.
Removing the brake disc
Remove the wheel.
Remove the caliper assembly and hang it with a wire.
Then loosen the two drive screws and remove the drive.
Pic. 6.45. Checking the thickness of the brake disc
Check disc for signs of wear or damage and replace if necessary (pic. 6.45).