GM Celebrity/Century/Ciera/6000 1982-1996 Repair Guide

Brake Caliper

Print


CAUTION
Brake shoes may 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.

REMOVAL & INSTALLATION



See Figures 1, 2 and 3

  1. Siphon 2 / 3 of the brake fluid out of the master cylinder reservoir.
  2.  
  3. Release the parking brake.
  4.  
  5. Loosen the lug nuts, then raise and safely support the vehicle.
  6.  
  7. Remove the tire and wheel assembly.
  8.  
  9. Install two wheel nuts to secure the rotor in place.
  10.  



Click image to see an enlarged view

Fig. Fig. 1: Exploded view of caliper model 3257



Click image to see an enlarged view

Fig. Fig. 2: Exploded view of caliper model 3264, notice the bleeder screw is in a different location that in model 3257

  1. Using a large C-clamp, position the clamp on the caliper housing and against the back of the outboard pad and lining. Tighten the clamp slowly to press the piston into the caliper bore.
  2.  



Click image to see an enlarged view

Fig. Fig. 3: A large C-clamp can be used to seat the piston in the caliper

  1. Remove the bolt attaching the hose fitting, only if the caliper is to be removed for overhaul. If only the pads are to be replaced, there is no need to disconnect the hose fitting.
  2.  
  3. Plug the opening in the caliper and the pipe to prevent fluid from seeping out and contamination.
  4.  
  5. Remove the Allen head caliper mounting bolts. Inspect them for corrosion and replace them if necessary.
  6.  

To install:
  1. Coat the bushings with silicone or grease.
  2.  
  3. Install the caliper and brake pads over the rotor, in the mounting bracket.
  4.  
  5. Install the mounting bolt and sleeve assembly, then tighten the mounting bolt to 28 ft. lbs. (38 Nm) for 1982-84 models and 38 ft. lbs. (51 Nm) for 1985-96 models.
  6.  
  7. Measure the clearance between the caliper and the bracket stops. If needed, remove the caliper and file down the ends of the bracket stops to provide clearance. The caliper may appear to be touching the lower abutment and still not be interfering. The caliper should slide freely on the mounting bolt and sleeve assemblies.
  8.  
  9. Install the brake hose to the caliper. The brake hose fitting should be tightened to 33 ft. lbs. (45 Nm). Always use new fasteners.
  10.  
  11. Install the wheel and tire, hand-tighten the lug nuts. Lower the vehicle, then tighten the lug nuts to 100 ft. lbs. (136 Nm).
  12.  
  13. Top off the brake fluid.
  14.  

OVERHAUL



  1. Remove the calipers.
  2.  
  3. Place some cloths or a slat of wood in front of the piston. Remove the piston by applying compressed air to the fluid inlet fitting. Use just enough air pressure to ease the piston from the bore.
  4.  


CAUTION
Do not try to catch the piston with your fingers, which can result in serious injury.

  1. Remove the piston dust boot.
  2.  
  3. Remove the bleeder screw and cap from the caliper.
  4.  
  5. Inspect the piston for scoring, nicks, corrosion, wear, and damaged or worn chrome plating. Replace the piston if any defects are found.
  6.  
  7. Remove the piston seal from the caliper bore groove using a pick. Do not use a screwdriver, which will damage the bore. Inspect the caliper bore for nicks, corrosion and so on. Very light wear can be cleaned up with crocus cloth. Use finger pressure to rub the crocus cloth around the circumference of the bore, do not slide it in and out. More extensive wear or corrosion warrants replacement of the part.
  8.  

To assemble:
  1. Clean any parts which are to be reused in denatured alcohol. Dry them with compressed or allow to air dry. Don't wipe the parts dry with a cloth, which will leave behind bits of lint.
  2.  
  3. Install the bleeder screw, tightening it to 110-120 inch lbs. (13-14 Nm)
  4.  
  5. Lubricate a new seal, with clean brake fluid. Install the seal in its groove, making sure it is fully seated and not twisted.
  6.  
  7. Install the new dust boot on the piston. Lubricate the bore of the caliper with clean brake fluid and insert the piston into its bore. Position the boot in the caliper housing and seat it with a seal driver of the appropriate size, or tool No. J-29077.
  8.  
  9. Install the caliper bushings. Lubricate the beveled end that is flush with the caliper, with silicone.
  10.  
  11. Install the pads, the caliper and bleed the brakes.
  12.  
  13. Install the wheel and tire assembly. Hand-tighten the lug nuts.
  14.  
  15. Lower the vehicle, then tighten the lug nuts to 100 ft. lbs. (136 Nm).
  16.  

 
label.common.footer.alt.autozoneLogo