- Plug the master cylinder inlet to prevent brake hydraulic fluid from leaking.
- Remove the brake drums and shoes.
- Working from behind the brake backing plate, disconnect the hydraulic line from the wheel cylinder.
- Unfasten the screws retaining the wheel cylinder and carefully withdraw it.
- Attach the wheel cylinder to the backing plate and torque the bolts to 7 ft. lbs. (10 Nm).
- Connect the hydraulic line to the wheel cylinder and tighten it securely.
- Install the brake shoes and drums.
- Fill the master cylinder to the proper level with clean brake fluid. Bleed the brake system and check the system for leaks.
Wheel cylinder overhaul kits may be available, but often at little or no savings over a reconditioned wheel cylinder. It often makes sense with these components to substitute a new or reconditioned part instead of attempting an overhaul.
If no replacement is available, or you would prefer to overhaul your wheel cylinders, the following procedure may be used. When rebuilding and installing wheel cylinders, avoid getting any contaminants into the system. Always use clean, new, high quality brake fluid. If dirty or improper fluid has been used, it will be necessary to drain the entire system, flush the system with proper brake fluid, replace all rubber components, then refill and bleed the system.
- Remove the wheel cylinder from the vehicle and place on a clean workbench.
- First remove and discard the old rubber boots, then withdraw the pistons. Piston cylinders are equipped with seals and a spring assembly, all located behind the pistons in the cylinder bore.
- Remove the remaining inner components, seals and spring assembly. Compressed air may be useful in removing these components. If no compressed air is available, be VERY careful not to score the wheel cylinder bore when removing parts from it. Discard all components for which replacements were supplied in the rebuild kit.
- Wash the cylinder and metal parts in denatured alcohol or clean brake fluid.
- Allow the parts to air dry or use compressed air. Do not use rags for cleaning, since lint will remain in the cylinder bore.
- Inspect the piston and replace it if it shows scratches.
- Lubricate the cylinder bore and seals using clean brake fluid.
- Position the spring assembly.
- Install the inner seals, then the pistons.
- Insert the new boots into the counterbores by hand. Do not lubricate the boots.
- Install the wheel cylinder.