GM Cavalier/Sunbird/Skyhawk/Firenza 1982-1994

Brake Disc (Rotor)



See Figure 1

You should always replace the rotors on both front wheels at the same time. Failure to do so will result in uneven braking action and premature wear.

  1. Raise and safely support the vehicle. Remove the tire and wheel assembly.
  3. Push the piston into the caliper bore to provide clearance between the brake pads and the rotor as follows:
    1. Install a large C-clamp over the top of the caliper housing and against the back of the outboard shoe.
    3. Slowly tighten the clamp until the piston is pushed into the caliper bore enough slide the caliper off of the rotor.

  5. Unfasten the caliper mounting bolts, then carefully remove the caliper (along with the brake pads) from the rotor. Do not disconnect the brake line; instead, wire the caliper out of the way with the line still connected.

Click image to see an enlarged view

Fig. Fig. 1: Removing the rotor from the hub

  1. Remove the rotor by simply pulling it off of the hub and bearing assembly.
  3. The installation is the reverse of the removal procedure.


Check the disc brake rotor for scoring, cracks or other damage. Rotor run-out should be measured while the rotor is installed, while rotor thickness/thickness variation may be checked with the rotor installed or removed. Use a dial gauge to check rotor run-out. Check the rotor thickness to make sure it is greater than minimum thickness and check for thickness variations using a caliper micrometer.

Thickness Variation
  1. Measure the thickness at four or more points on the rotor. Make all measure measurements at the same distance in from the edge of the rotor. Use a micrometer calibrated in ten-thousandths of an inch.
  3. A rotor that varies in thickness by more than 0.0005 in. (0.013mm) can cause pedal pulsation and/or front end vibration during brake applications. A rotor that does not meet these specifications should be resurfaced to specifications or replaced.

Lateral Run-out
  1. Remove the wheel and tire assembly.
  3. Fasten the lug nuts to retain the rotor.
  5. Secure a dial indicator to the steering knuckle so the indicator button contacts the rotor at about 0.5 in. (13mm) from the outer edge of the rotor.
  7. Set the dial indicator to zero.
  9. Turn the wheel one complete revolution and observe the total indicated run-out.
  11. If the run-out exceeds 0.0031 in. (0.08mm), resurface or replace the rotor.