See Figures 1 and 2
When the brake drums are removed, carry out an inspection of the wheel cylinder boots for cuts, tears, cracks, or leaks. If any of these are present, the wheel cylinder should have a complete overhaul performed.
Preservative fluid is used during assembly; its presence in small quantities does not indicate a leak.
- Remove the brake shoes and check them. Replace them if they are soaked with grease or brake fluid.
- Detach the brake hose.
- Unfasten the wheel cylinder attachment bolts and slide the wheel cylinder off its support.
See Figure 3
- Pry the boots off from either end of the wheel cylinder and withdraw the pushrods. Push in one of the pistons, to force out the other piston, its cup, the spring, the spring cup, and the piston, itself.
- Wash the pistons, the wheel cylinder housing, and the spring in fresh brake fluid, or in denatured alcohol, and dry them off using compressed air.
- Inspect the cylinder bore wall for signs of pitting, scoring, etc. If it is badly scored or pitted, the entire cylinder should be replaced. Light scratches or corrosion should be cleaned up with crocus cloth.
Disregard the black stains from the piston cups that appear on the cylinder wall; they will do no damage.To assemble:
- Dip the pistons and the cups in clean brake fluid. Replace the boots with new ones, if they show wear or deterioration. Coat the wall of the cylinder bore with clean brake fluid.
- Place the spring in the cylinder bore. Position the cups in either end of the cylinder with the open end of the cups facing inward (toward each other).
- Place the pistons in either end of the cylinder bore with the recessed ends facing outward (away from each other).
- Install the boots over the ends of the cylinder and push down until each boot is seated, being careful not to damage either boot.
- Install the wheel cylinder on its support.
- Attach the jumper tube to the wheel cylinder. Install the brake hose on the frame bracket. Connect the brake line to the hose. Connect the end of the brake hose. Connect the end of the brake hose through the end of the stand-off. Attach the jumper tube to the brake hose and attach the hose to the stand-off.