REMOVAL & INSTALLATION
- Use a syringe or similar tool to remove 2 / 3 of the brake fluid from the master cylinder reservoir.
- Raise and safely support the vehicle.
- Remove the wheel and tire assembly, then reinstall 2 lug nuts to retain the disc brake rotor.
- Remove the disc brake caliper from the mounting bracket, but do not disconnect the brake hose from the caliper. Suspend the caliper with wire from the coil spring.
- Use a small prybar to disengage the buttons on the outboard disc brake pad from the holes in the caliper housing. Remove the outboard disc brake pad.
- Remove the inboard disc brake pad.
- Inspect the disc brake rotor and machine or replace, as necessary.
- Wipe the outside surface of the caliper piston boot clean using denatured alcohol.
- Using a C-clamp, bottom the caliper piston into the caliper bore. Tighten the clamp slowly, and be careful not to damage the piston or piston boot. After bottoming the piston, use a small plastic or wood tool to lift the inner edge of the boot next to the piston and press out any trapped air; the boot must lay flat.
- Install the inboard disc brake pad by snapping the retainer spring into the piston. Make sure the pad lays flat against the piston and does not touch the boot. If the pad contacts the boot, remove the pad and reseat or reposition the boot.
- Install the outboard disc brake pad. Position the pad so that the wear sensor is at the trailing edge of the pad during forward wheel rotation on all except 1990 Deville and Fleetwood. On 1990 Deville and Fleetwood, position the pad so that the wear sensor is at the leading edge of the pad during forward wheel rotation. The back of the pad must lay flat against the caliper.
- Install the disc brake caliper.
- Install the wheel and tire assembly and lower the vehicle.
- Apply the brake pedal several times to position the caliper piston and seat the brake pads in the caliper.
- Check the brake fluid level in the master cylinder and add fluid as necessary.
Inspect the disc brake pads every 6000 miles and any time the wheels are removed. Check both ends of the outer pad by looking in at each end of the caliper. These points are where the highest rate of wear normally occurs. Check the inner pad by looking down through the hole in the top of the caliper. When any lining thickness is worn to within 1 / 32 in. (0.76mm) of the backing plate or rivet, the pads must be replaced in axle sets. Some inner pads have a thermal layer against the backing plate, integrally molded with the lining; don't confuse this extra layer with uneven inboard-outboard lining wear.
The outer disc brake pad is also equipped with a wear sensor. When the lining is worn, the sensor contacts the disc brake rotor and produces a warning noise, indicating that disc brake pad replacement is necessary.