Brake Caliper Mounting Plate Wear Adjustment
WARNING: This page is about a different car, the 2002 GMC Sierra, 2002 GMC Cab & Chassis Sierra, 2002 Chevrolet Silverado, and 2002 Chevrolet Cab & Chassis Silverado. However, it is still accessible from the selected car via links, so may be relevant.
CAUTION:
Support the brake caliper with heavy mechanic's 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.
NOTE:
Brake calipers have wear shims available to compensate for wear at the caliper to mounting bracket contact points. A rattling sound or clunking noise may be heard from the brake area when the caliper and/or mounting bracket contact points become excessively worn. Use the following procedure to measure and correct this condition.
- Remove the caliper from the mounting bracket and support the caliper with heavy mechanic's wire or equivalent. Do not disconnect the hydraulic brake hose from the caliper. See BRAKE CALIPER under REMOVAL & INSTALLATION.
- Clean identified surfaces with a wire brush. See Fig 1 .
- Smooth any deep nicks or gouges with a file.
- Measure the caliper contact surface for wear by performing the following steps:
- Lay a straight edge across the caliper surfaces. See Fig 2 .
- Measure the maximum depth of any wear on the surfaces using feeler gage.
- Replace any calipers worn to a depth of 0.05" (1.25 mm) or more. See BRAKE CALIPER under REMOVAL & INSTALLATION.
- Install a NEW support key without the spring. See Fig 3 .
- Install the caliper lock mounting bolt.
- Measure caliper to mounting bracket by performing the following steps.
- Insert a screw driver into the center of the key bumper gap. See Fig 4 .
- Pry the screw driver firmly into the center of the key bumper gap to ensure that the caliper is sitting at the surfaces.
- Measure the bumper gap with the largest feeler gauge that will fit into the gap on either side of the screw driver.
- Select a shim based on the bumper gap measurement. See CALIPER WEAR SHIM SPECIFICATIONS table.
- Install a caliper shim by performing the following steps:
- Remove the caliper from the mounting bracket and support the caliper with heavy mechanic's wire or equivalent. Do not disconnect the hydraulic brake hose from the caliper. See BRAKE CALIPER under REMOVAL & INSTALLATION.
- Install the shim on the mounting bracket V-way opposite from the key and the spring V-way.
- Install the caliper using a new support key and spring. See BRAKE CALIPER under REMOVAL & INSTALLATION.
- Remeasure the bumper gap. If the gap exceeds 0.058" (1.50 mm). Install a thicker shim. Inspect caliper wear shim specifications. See CALIPER WEAR SHIM SPECIFICATIONS table. If required, replace the mounting bracket. See BRAKE CALIPER MOUNTING PLATE under REMOVAL & INSTALLATION.
CALIPER WEAR SHIM SPECIFICATIONS
| More Than | But Not Exceeding | Shim Thickness | Shim Part Number |
|---|---|---|---|
| 0 | 0.058" (1.473 mm) | None Required | None Required |
| 0.058" (1.473 mm) | 0.101" (2.565 mm) | 0.025" (0.635 mm) | 15625734 |
| 0.101" (2.565 mm) | 0.145" (3.683 mm) | 0.045" (1.143 mm) | 15625735 |
| If the bumper gap exceeds 0.145" (3.683 mm), then remove the old caliper and replace it with a NEW caliper. If the bumper gap with the NEW caliper measures between 0.058-0.145" (1.473-3.683 mm) then select a shim from the table. If the bumper gap with the NEW caliper exceeds 0.145" (3.683 mm), then replace the mounting bracket plate. Use a NEW key and a NEW spring when assembling the NEW components. | |||