GM Chevy Mid-Size Cars 1964-1988 Repair Guide

Wheel Cylinders


Brake shoes contain asbestos, which has been determined to be a cancer causing agent. Never clean the brake surfaces with compressed air! Avoid inhaling any dust from any brake surface! When cleaning brake surfaces, use a commercially available brake cleaning fluid.


  1. Raise and support the front of the vehicle safely using jackstands.
  3. Remove the wheel and the brake drum for access to 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. 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.

  1. Clean away all dirt, crud and foreign material from around wheel cylinder. It is important that dirt be kept away from the brake line when the cylinder is disconnected.
  3. Disconnect the inlet tube line. Plug or cap the line opening to prevent system contamination or excessive fluid loss.

Wheel cylinders are retained to the rear of the brake backing plate by two types of fasteners. One type uses a round retainer with locking clips while the other simply uses two bolts threaded into the wheel cylinder body.

  1. To remove the round retainer type cylinders, insert two awls or pins into the access slots between the wheel cylinder pilot and the retainer locking tabs. Bend both tabs away simultaneously. The wheel cylinder can be removed, as the retainer is released.
  3. To remove the bolted wheel cylinders, loosen and remove the bolts from the back side of the backing plate, then remove the wheel cylinder assembly.

To install:
  1. For round retainer type wheel cylinders, position the cylinder and hold it in place with a wooden block between the cylinder and the axle flange. Install the new retainer clip, using a 1 1 / 8 in. 12-point socket and socket extension. The socket is used to assure that the retainer seats evenly.
  3. For bolt type wheel cylinders, position the cylinder and secure using the retaining bolts.
  5. Remove the cap or plug, then connect and secure the inlet line.
  7. Assemble the remaining brake components which were removed, then install the tire and wheel.
  9. Bleed the wheel cylinder, then remove the jackstands and carefully lower the vehicle.


Wheel cylinder overhaul is virtually the same for front drum brakes as it is for the rear. For information, please refer to the overhaul procedure found later in this section under rear drum brakes. 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.