Rebuild

For additional information see Notes, Warnings, and Hints.

Inspecting Wheel Cylinder:

Wheel cylinders should not be disassembled unless they are leaking. Carefully pull lower edges of wheel cylinder boots away from cylinder, and note whether interior is wet with brake fluid. Excessive fluid at this point indicates leakage past piston cups and a need for wheel cylinder overhaul.

NOTICE: A slight amount of fluid is nearly always present and acts as a lubricant for the piston. It is not necessary to remove the brake cylinder from the backing plate to disassemble, inspect, hone, and overhaul the cylinder. Removal is necessary only if the cylinder is damaged or scored beyond service.

DISASSEMBLY
1. Disengage wheel cylinder boots from retaining grooves in wheel cylinder casting. Remove each boot and piston from wheel cylinder as an assembly.
2. Remove wheel cylinder rubber cups and spring and expander assemblies from wheel cylinder bore.
3. Discard all rubber parts.
4. Remove bleeder screw from cylinder.
5. Wash all parts in clean denatured alcohol or brake parts cleaner.
6. Inspect pistons for scratches, scoring, or other visible damage. Replace if necessary.

NOTICE: Always replace rubber cups and dust boots.

7. Inspect cylinder bore for score marks or rust. If either condition is present, cylinder bore must be honed. However cylinder should not be honed more than 0.08 mm (0.003 in) beyond its original diameter.
8. Wash cylinder with clean denatured alcohol or brake parts cleaner after honing. Dry it with compressed air.
9. Make sure that bleeder hole is open.

ASSEMBLY

NOTICE: Use all parts in the wheel cylinder service kit.

1. Apply light coating of DOT 3 brake fluid to all internal parts.
2. Thread bleeder screw into cylinder.
3. Insert return spring and cup expander assembly, and pistons into their respective positions in cylinder bore. Place a boot over each end of cylinder.
4. Install wheel cylinder.

NOTICE: Ensure that brake line is installed in lower wheel cylinder hole and bleed screw in upper hole. Always perform brake bleeding procedures before driving vehicle.