GM Service Manual Online
For 1990-2009 cars only

Tools Required:

J 26900-1 Combimike Micrometer

  1. Reposition and support the caliper and the brake pads. Refer to Front Disc Brake Pads Replacement or to Rear Disc Brake Pads Replacement as applicable.
  2. Clean the brake pad lining contact surfaces of the brake rotor with denatured alcohol or an equivalent brake cleaner.
  3. Inspect the braking surfaces of the brake rotor for the following braking surface conditions:
  4. • Heavy rust and/or pitting
    • Use an abrasive disc in order to remove light surface rust.
    • Refinish the rotor in order to remove heavy surface rust and/or pitting.
    • Cracks and/or heat spots
    • Excessive blueing discoloration
  5. If the braking surfaces of the brake rotor exhibits one or more of the braking surface conditions, refinish or replace the brake rotor.

  6. Object Number: 693340  Size: SH
  7. Use the J 26900-1 or an equivalent micrometer in order to measure any grooves on the rotor braking surface.
  8. Compare the groove depth to the following specification:
  9. Specification
    The maximum groove depth is 0.4 mm (0.016 in).

  10. If the groove depth exceeds the specification, or if an excessive amount of scoring is present, refinish or replace the brake rotor. In order to refinish the brake rotor, refer to Brake Rotor Refinishing . In order to replace the brake rotor, refer to Front Brake Rotor Replacement or to Rear Brake Rotor Replacement as applicable.