REMOVAL & INSTALLATION
- Raise and support the rear of the vehicle safely on jackstands.
- Remove the tire and wheel assembly.
- Matchmark and remove the brake drum to access the wheel cylinder assembly.
In most cases, the wheel cylinders may be removed from the backing plate without completely removing the brake shoes and related components, however completely removing the shoes will make the operation MUCH easier. If the shoes are not completely removed, some of the upper springs must be removed in order to allow the shoes to spread and provide the necessary clearance for wheel cylinder removal.
- Remove the brake shoes or disconnect them sufficiently for adequate wheel cylinder clearance.
- Clean away all dirt and foreign material from around wheel cylinder. It is important that dirt be kept away from the brake line when the cylinder is disconnected.
- Disconnect the inlet tube line from the back of the wheel cylinder. Immediately plug or cap the line to prevent system contamination or excessive fluid loss.
- Loosen and remove the bolts from the rear of the backing plate, then remove the wheel cylinder assembly.
- Position the wheel cylinder, then install the retaining bolts and tighten to 115 inch lbs. (13 Nm).
- Remove the cap or plug, then connect and secure the hydraulic inlet line. Tighten the fitting to 16 ft. lbs. (22 Nm).
- Install the brake shoes and remaining brake components.
- Align and install the brake drum, then install the tire and wheel assembly.
- Adjust the brake shoes and bleed the brake system. Refer to the drum adjustment and bleeding procedures in this section.
- Remove the jackstands and carefully lower the vehicle.
See Figures 1 and 2
Wheel cylinder overhaul kits are available for most wheel cylinders, but often at little or no savings as compared to a reconditioned wheel cylinder. It often makes sense with these components to substitute a new or reconditioned part instead of attempting to 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 install 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, refill, and bleed the system.
- Remove the wheel cylinder from the vehicle and place on a clean work surface.
- First remove and discard the old rubber boots from either side of the cylinder.
- Withdraw the pistons from the cylinder. 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 needed. 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 to the vehicle.