GM Cadillac 1967-1989 Repair Guide

Disc Brake Pads

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INSPECTION



See Figures 1, 2 and 3

Brake pads should be inspected at least once a year or at 7,500 miles, whichever occurs first. Check both ends of the outboard shoe, looking in at each end of the caliper; then check the lining thickness on the inboard shoe, looking down through the inspection hole. Lining should be more than 0.020 in. (0.051mm) thick above the rivet (so that the lining is thicker than the metal backing). Keep in mind that any applicable state inspection standards that are more stringent take precedence. All four pads must be replaced if one shows excessive wear.

All 1979 and later models have a wear indicator that makes a noise when the linings wear to a degree where replacement is necessary. The spring clip is an integral part of the inboard shoe and lining. When the brake pad reaches a certain degree of wear, the clip will contact the rotor and produce a warning noise.



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Fig. Fig. 1: Front disc brake pad wear indicator - 1979 and later



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Fig. Fig. 2: Disc brake pad inspection



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Fig. Fig. 3: New and worn brake pads

REMOVAL & INSTALLATION



See Figures 4, 5, 6, 7, 8 and 9


CAUTION
Brake 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 any brake surface! When cleaning brake surfaces, use a commercially available brake cleaning fluid.

  1. Siphon off 2 / 3 of the brake fluid from the master cylinder.
  2.  

The insertion of the thicker replacement pads will push the caliper piston back into its bore and will cause a full master cylinder to overflow.

  1. Jack the car up and support it with jackstands. Remove the wheel(s).
  2.  
  3. Install a C-clamp on the caliper so that the solid side of the clamp rests against the back of the caliper and the screw end rests against the metal part of the outboard pad.
  4.  
  5. Tighten the clamp until the caliper moves enough to bottom the piston in its bore. Remove the clamp.
  6.  
  7. Remove the two allen head caliper mounting bolts enough to allow the caliper to be pulled off the disc.
  8.  
  9. Remove the inboard pad and dislodge the outboard pad. Place the caliper where it won't be supported by the brake hose (hang it by a wire hook from the frame).
  10.  
  11. Remove the pad support spring clip from the piston.
  12.  
  13. Remove the two bolt ear sleeves and the four rubber bushings from the ears.
  14.  
  15. Brake pads should be replaced when they are worn to within 1 / 32 in. (0.80mm) of the rivet heads.
  16.  

To install:
  1. Check the inside of the caliper for leakage and the condition of the piston dust boot.
  2.  
  3. Lubricate the two new sleeves and four bushings with a silicone spray.
  4.  
  5. Install the bushings in each caliper ear. Install the two sleeves in the two inboard ears.
  6.  
  7. If the piston was not fully bottomed during removal there may not be sufficient clearance for new pad insallation. If necessary, install the pad support spring clip and the old pad into the center of the piston. You will then push this pad down to get the piston flat against the caliper. Use a C-clamp or a large pair of channel-type pliers to carefully depress the piston back into the bore. Make sure the piston boot is not pinched or otherwise damaged. DO NOT attempt to force the piston any further then necessary to insert the new pads.
  8.  

If the piston will not slide easily back into the bore DO NOT force it. Have an assistant hold the caliper and loosen the bleeder valve to relieve pressure, while you carefully press the old pad (in order to push on the piston) and slowly insert the piston until it is flush with the caliper surface. When it is flush, immediately close the bleeder valve so that no air gets into the system. Once the brakes are installed, the caliper should be properly bled to assure no air was drawn into the system.

  1. Position the outboard shoe with the ears of the shoes over the caliper ears and the tab at the bottom engaged in the caliper cutout notch.
  2.  

On models with wear sensors, make sure the wear sensor is toward the rear of the caliper.

  1. With the two shoes in position, place the caliper over the brake disc and align the holes in the caliper with those of the mounting bracket.
  2.  


CAUTION
Make certain that the brake hose is not twisted or kinked.

  1. Install the mounting bracket bolts through the sleeves in the inboard caliper ears and through the mounting bracket, making sure that the ends of the bolts pass under the retaining ears of the inboard shoe.
  2.  

When installing the caliper on 1986-89 Eldorados and Sevilles, NEW caliper mounting bolts must be used.

  1. Tighten the bolts into the bracket and tighten to 35 ft. lbs. (47 Nm) except for 1986-89 vehicles which should be tightened to 63 ft. lbs. (85 Nm). Bend over the outer pad ears.
  2.  
  3. Install the front wheel and lower the car.
  4.  
  5. Add fluid to the master cylinder reservoirs so that they are 1 / 4 in. from the top.
  6.  
  7. Test the brake pedal by pumping it to obtain a hard pedal. Check the fluid level again and add fluid as necessary. Do not move the vehicle until a hard pedal is obtained. Bleed the brakes if necessary.
  8.  



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Fig. Fig. 4: Use a C-clamp to seat the caliper piston



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Fig. Fig. 5: The Allen head caliper bolts must go under the pad retaining ears



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Fig. Fig. 6: Installing inboard brake pad



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Fig. Fig. 7: Proper retaining spring installation



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Fig. Fig. 8: Compressing caliper with pry bar



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Fig. Fig. 9: Clinching outboard pad during installation

 
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