GM Caprice 1990-1993 Repair Guide

Brake Caliper

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REMOVAL & INSTALLATION



See Figure 1



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Fig. Fig. 1: Exploded view of single piston front caliper


CAUTION
Brake pads 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. Remove 2 / 3 of the brake fluid from the master cylinder. Raise the vehicle and remove the wheel.
  2.  
  3. Place a C-clamp across the caliper, positioned on the brake pads. Tighten it until the piston is forced into its bore.
  4.  
  5. Remove the C-clamp. Remove the bolt holding the brake hose to the caliper.
  6.  
  7. Remove the caliper mounting bolts. Inspect them for corrosion and replace them if necessary. Remove the caliper.
  8.  

To install:
  1. Position the caliper with the brake pad installed and install caliper mounting bolts. Mounting bolt torque is 38 ft. lbs. (51 Nm.) for the caliper.
  2.  
  3. Install the bolt holding the brake hose to the caliper and tighten to 18-30 ft. lbs. (24-40 Nm.).
  4.  
  5. Fill the master cylinder with brake fluid.
  6.  
  7. Install the wheels and lower the vehicle.
  8.  


CAUTION
Before moving the vehicle, pump the brakes several times to seat the brake pad against the rotor.

OVERHAUL



See Figures 2, 3 and 4



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Fig. Fig. 2: Using compressed air to remove the piston from the caliper bore



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Fig. Fig. 3: Remove piston boot using an awl



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Fig. Fig. 4: Installing boot into caliper

  1. Remove the caliper.
  2.  
  3. Remove the pads.
  4.  
  5. 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 east the piston from the bore.
  6.  


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

  1. Remove the piston boot with a screwdriver, working carefully so that the piston bore is not scratched.
  2.  
  3. Remove the bleeder screw.
  4.  
  5. Inspect the piston for scoring, nicks, corrosion, wear, etc., 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 piece of pointed wood or plastic. Do not use a screwdriver, which will damage the bore. Inspect the caliper bore for nicks, corrosion, and wear. 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.  
  9. Clean any parts which are to be reused in denatured alcohol. Dry them with compressed air or allow to air dry. Don't wipe the parts dry with a cloth, which will leave behind bits of lint.
  10.  
  11. Lubricate the new seal, provided in the repair kit, with clean brake fluid. Install the seal in its groove, making sure it is fully seated and not twisted.
  12.  
  13. 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 with a seal driver of the appropriate size, or G.M. tool no. J-26267.
  14.  
  15. Install the bleeder screw, tightening to 80-140 inch lbs. (9-16 Nm). Do not over tighten.
  16.  
  17. Install the pads, install the caliper, and bleed the brakes.
  18.  

 
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