GM Service Manual Online
For 1990-2009 cars only

Bendix® calipers have wear shims available to compensate for wear at the caliper to anchor plate contact points. A rattling sound, originating from the front brake area, will occur when the caliper and anchor plate are excessively worn. Use the following procedure to measure and correct this condition.

    Notice: Support the brake caliper with heavy mechanic wire, or equivalent, whenever it is separated from its mount and the hydraulic flexible brake hose is still connected. Failure to support the caliper in this manner will cause the flexible brake hose to bear the weight of the caliper, which may cause damage to the brake hose and in turn may cause a brake fluid leak.

  1. Remove the caliper.

  2. Object Number: 156349  Size: SH
  3. Clean surfaces (1-4) with a wire brush.
  4. Smooth any deep nicks or gouges with a file.

  5. Object Number: 156354  Size: SH
  6. Measure the caliper contact surface for wear by performing the following steps.
  7. 4.1. Lay a straight edge (1) across the caliper surfaces.
    4.2. Measure the maximum depth of any wear on the surfaces using feeler gage (2).
    4.3. Replace any calipers worn to a depth of 1.25 mm (0.050 in) or more.

    Object Number: 156357  Size: SH
  8. Measure caliper to anchor plate wear by performing the following steps.
  9. 5.1. Install the caliper.
    5.2. Install a new standard size key without the spring.
    5.3. Install the key retention bolt.
    5.4. Insert a screw driver into the center of the key bumper gap (1).
    5.5. Pry the screw driver firmly into the center of the key bumper gap to ensure that the caliper is sitting at the surfaces.
    5.6. Measure the bumper gap with the largest feeler gauge that will fit into the gap on either side of the screw driver.
    5.7. Select a shim based on the bumper gap measurement. Refer to Caliper Wear Shim Specifications .
  10. Replace the caliper by performing the following steps.
  11. 6.1. Remove the caliper from the anchor plate.
    6.2. Install the shim on the anchor plate V-way opposite from the key and the spring V-way.
    6.3. Install the caliper using a new key and a new spring.
  12. Remeasure the bumper gap. Install a thicker shim or replace the components if the gap exceeds 1.50 mm (0.058 in). Refer to Caliper Wear Shim Specifications .