GM Prizm/Nova 1985-1993 Repair Guide

Brake Pads

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INSPECTION



The rear brake pads may be inspected without removal. With the rear end elevated and supported, remove the wheel(s).

View the pads - inner and outer - through the cut-out in the center of the caliper. Remember to look at the thickness of the pad friction material (the part that actually presses on the disc) rather than the thickness of the backing plate which does not change with wear.

Remember that you are looking at the profile of the pad, not the whole thing. Brake pads can wear on a taper which may not be visible through the window. It is also not possible to check the contact surface for cracking or scoring from this position. This quick check can be helpful only as a reference; detailed inspection requires pad removal.

REMOVAL & INSTALLATION



See Figures 1 through 5


CAUTION
Brake pads and 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 brake surfaces! When cleaning brakes, use commercially available brake cleaning fluids.

  1. Raise and safely support the rear of the vehicle on jackstands. Block the front wheels.
  2.  



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Fig. Fig. 1: Rear disc brake components



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Fig. Fig. 2: Correct method for raising the rear caliper to gain access to the pads



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Fig. Fig. 3: Installing support plates and anti-rattle shims



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Fig. Fig. 4: Using the GM tool to retract the rear caliper piston



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Fig. Fig. 5: Align the stopper groove with the pad protrusion

  1. Siphon a sufficient quantity of brake fluid from the master cylinder reservoir to prevent the brake fluid from overflowing the master cylinder when removing or installing the brake pads. This is necessary as the piston must be forced into the cylinder bore to provide sufficient clearance to install the pads.
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  3. Remove the wheel, then reinstall 2 lug nuts finger tight to hold the disc in place.
  4.  

Disassemble brakes one wheel at a time. This will prevent parts confusion and also prevent the opposite caliper piston from popping out during pad installation.

  1. Remove the lower mounting bolt from the mounting bracket. Do not remove the caliper main (upper) pin.
  2.  
  3. Lift the caliper from the bottom so that it hinges upward on the upper pin. Use a piece of wire to hold the caliper up. Do not allow the brake hose to become twisted or kinked during this operation.
  4.  
  5. Remove the brake pads with their shims, springs and support plates.
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  7. Check the rotor thickness and run-out following the procedures explained under Front Disc Brakes in this Section. Refer to the Specifications Chart at the end of this Section for the correct measurements.
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  9. Install new pad support plates to the lower sides of the mounting bracket.
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  11. Install new anti-rattle springs to the upper side of the mounting bracket.
  12.  

To install:
  1. Install a new anti-squeal shim to the back of each pad and install the pads onto the mounting bracket. Install the pads so that the wear indicators are on the uppermost side.
  2.  
  3. Use GM tool J-37149 or equivalent to turn the caliper piston clockwise while pressing it into the caliper bore. Proceed until it locks.
  4.  
  5. Lower the caliper so that the pad protrusion fits into the piston stopper groove. Install the mounting bolts and tighten to 14 ft. lbs. Install the rear wheel.
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  7. Depress the brake pedal until a firm pedal is obtained.
  8.  
  9. Repeat this procedure on the remaining caliper.
  10.  
  11. Pump the brakes until a firm pedal is felt. Lower the vehicle and fill the master cylinder reservoir to the correct level.
  12.  

 
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