- Raise and safely support the rear of the vehicle on jackstands. Block the front wheels. Remove the rear wheel and install 2 lug nuts hand tight, to hold the rotor in place.
- Place a container under the caliper to catch brake fluid that may leak from the brake hose as it is disconnected. Disconnect the union bolt holding the brake hose to the caliper. Once disconnected, plug or cap the brake hose to prevent excess brake fluid loss and possible system contamination.
- Remove the clip from the parking brake cable and remove the cable. Remove the caliper bolt.
- Swing the caliper up and remove the parking brake pin clip. Push on the parking brake crank (arm) to releave the tension and remove the pin.
- Slide the caliper off of the upper pin. Remove the brake pads, springs and clips as required.
See Figures 1 through 7
- Remove the slide bushings and dust boots.
- Remove the set ring and dust boot from the caliper piston.
- Using GM Tool J-37149 or its equivalent, remove the caliper piston from the bore.
- Remove the seal from the inside of the caliper bore.
- Install GM Tool J-37150 or its equivalent onto the adjusting bolt and lightly tighten it with a 14mm socket. Do not overtighten the tool; damage to the spring may result.
- Remove the snapring from the caliper bore.
- Carefully remove the adjusting bolt and disassemble it.
- Remove the parking brake strut.
- Remove the cable support bracket, then remove the torsion spring from the parking brake crank.
- Remove the parking brake crank from the caliper.
- Remove the parking brake crank boot by tapping it lightly on the metal portion of the boot. Do not remove the boot unless it is to be replaced.
- Use a pin punch to tap out the stopper pin.
- Check all the parts for wear, scoring, deterioration, cracking or other abnormal conditions. Corrosion - generally caused by water in the system - will appear as white deposits on the metal. Pay close attention to the condition of the inside of the caliper bore and the outside of the piston. Any sign of corrosion or scoring requires new parts; do not attempt to clean or resurface either face.
- The caliper overhaul kit will, at minimum, contain new seals and dust boots. A good kit will contain a new piston as well, but you may have to buy the piston separately. Any time the caliper is disassembled, a new piston is highly recommended in addition to the new seals.
- Clean all the components to be reused with an aerosol brake solvent and dry them thoroughly. Take any steps necessary to eliminate moisture or water vapor from the parts.
- Coat all the caliper components with fresh brake fluid from a new can.
Some repair kits come with special assembly lubricant for the piston and seal. Use this lubricant according to directions with the kit.
- Install the stopper pin into the caliper until the pin extends 25mm.
- Install the parking brake crank boot. Use a 24mm socket to tap the boot to the caliper.
- Install the parking brake crank onto the caliper. Make certain the crank boot is securely matched to the groove of the crank seal.
- Install the cable support bracket. Press the surface of the bracket flush against the wall of the caliper and tighten the bolt to 34 ft. lbs.
- Check that the clearance between the parking brake crank and the cable support is 6mm.
- Install the torsion spring.
- Inspect the crank sub-assembly, making sure it touches the stopper pin.
- Install the parking brake strut. Before adjusting the strut, adjust the rollers of the needle roller bearing so they do not catch on the caliper bore.
- Install a new O-ring on the adjusting bolt.
- Install the stopper, plate, spring, and spring retainer onto the adjusting bolt. Use Tool J-37150 and hand tighten the assembly. Make certain the inscribed portion of the stopper faces upward. Align the notches of the spring retainer with the notches of the stopper.
- Install the adjusting bolt assembly into the cylinder.
- Install snapring into the bore. Make certain the gap in the ring faces toward the bleeder side.
- Pull up on the adjusting bolt by hand to make certain it does not move.
- Move the parking brake crank by hand and make certain adjusting bolt moves smoothly.
- Install a new piston seal in the caliper bore.
- Install the piston into the caliper bore. Using Tool J-37149 or its equivalent, slowly screw the piston clockwise until it will not descend any further.
- Align the center of the piston stopper groove with the positioning marks of the caliper bore.
- Install the piston dust boot and its set ring.
- Install a new boot on the main (upper) caliper pin. Use a 21mm socket to press in the new boot.
- Install the slide bushings and boots onto the caliper.
- Install the brake pads, springs and clips.
- Install the caliper assembly to the main pin. Before installing the retaining bolts, apply a thin, even coating of anti-seize compound to the threads and slide surfaces. Don't use grease or spray lubricants; they will not hold up under the extreme temperatures generated by the brakes.
- Install the caliper mounting bolt and tighten it to 14 ft. lbs.
- Install the parking brake clip.
- Install the brake hose to the caliper. Always use new gaskets and tighten the union to 22 ft. lbs.
- Bleed the brake system.
- To automatically adjust the parking brake, pull up on the lever several times, then release the lever and step on the brake pedal.
- Double check that the parking brake crank touches the stopper.
- Install the rear wheel and lower the car to the ground.