See Figure 1
Wheel cylinder rebuilding kits are available for reconditioning wheel cylinders. The kits usually contain new cup springs, cylinder cups and, in some, new boots. The most important factor to keep in mind when rebuilding wheel cylinders is cleanliness. Keep all dirt away from the wheel cylinders when you are reassembling them.
- To remove the wheel cylinder, jack up the vehicle and remove the wheel, hub, and drum.
- Disconnect the brake line at the fitting on the brake backing plate.
- Remove the brake assemblies.
- Remove the screws or nuts that hold the wheel cylinder to the backing plate and remove the wheel cylinder from the vehicle.
- Remove the rubber dust covers on the ends of the cylinder. Remove the pistons and piston cups and the spring. Remove the bleeder screw and make sure it is not plugged.
- Discard all of the parts that the rebuilding kit will replace.
- Examine the inside of the cylinder. If it is severely rusted, pitted or scratched, then the cylinder must be replaced, as the piston cups won't be able to seal against the walls of the cylinder.
- Using a wheel cylinder home or emery cloth and crocus cloth, polish the inside of the cylinder. The purpose of this is to put a new surface on the inside of the cylinder. Keep the inside of the cylinder coated with brake fluid while honing.
- Wash out the cylinder with clean brake fluid after honing.
- When reassembling the cylinder, dip all of the parts in clean brake fluid. Reassemble in the reverse order of removal.