Disc Brake System Testing
WARNING: This page is about a different car, the 2002 Pontiac Montana, 2002 Oldsmobile Silhouette, and 2002 Chevrolet Venture. However, it is still accessible from the selected car via links, so may be relevant.
- Were you sent here from General Diagnosis? If so, go to next step. If not, go to DIAGNOSTIC STARTING POINT - HYDRAULIC BRAKE under TROUBLE SHOOTING.
- Visually inspect the disc brake pads for the following:
- Lining thickness.
- Uneven and/or abnormal wear, edge-to-edge and/or side-to-side.
- Evidence of contamination from an external substance.
- Looseness or damage, including pad hardware.
- Are any of the disc brake pads contaminated? If so, go to step 8 . If not, go to next step.
- Are any of the disc brake pads worn unevenly? If so, go to step 7 . If not, go to next step.
- Are any of the disc brake pads and/or pad hardware loose or damaged? If so, go to step 7 . If not, go to next step.
- Remove and inspect the worn disc brake pads for glazing, looseness, heat spots or damage. Replace the worn disc brake pads as a complete axle set. See FRONT BRAKE PADS under REMOVAL & INSTALLATION. Did you complete the inspection and replacement? If so, go to step 12 .
- Remove the disc brake calipers, as appropriate, from the mounting brackets and support the calipers. Do Not disconnect the hydraulic brake flexible hoses from the calipers.
- Inspect the disc brake caliper mounting bracket and the mounting/sliding hardware for the following conditions:
- Loose, bent, cracked, or damaged caliper mounting bracket.
- Binding or seized hardware.
- Worn, damaged or missing hardware components.
- Replace components as required. Refer to the following procedures, as required:
- See FRONT BRAKE CALIPER BRACKET under REMOVAL & INSTALLATION.
- See FRONT DISC BRAKE HARDWARE under REMOVAL & INSTALLATION.
- Replace the unevenly-worn, loose or damaged disc brake pads as a complete axle set. See FRONT BRAKE PADS under REMOVAL & INSTALLATION.
- Inspect the disc brake calipers, brake hoses and brake pipes for evidence of an external brake fluid leak. Replace any components found to be leaking brake fluid. Refer to the following procedures as required:
- See FRONT BRAKE CALIPER under REMOVAL & INSTALLATION.
- See FRONT BRAKE HOSE under REMOVAL & INSTALLATION.
- See REAR DISC BRAKE HOSE under REMOVAL & INSTALLATION.
- See BRAKE PIPE under REMOVAL & INSTALLATION.
- Inspect the wheel drive shaft outer seals (boots) for damage and evidence of a grease leak. Replace any wheel drive shaft seal (boot) that is found to be leaking grease which may be the source of the contamination to the pads. See appropriate FRONT DRIVE AXLES article. Did you find and correct the source of the leak causing contamination of the pads? If so, go to step 11 . If not, go to next step.
- Inspect the following systems for damage and evidence of an external fluid leak. Replace any components found to be leaking fluid which may be the source of the contamination to the pads. Refer to the following procedures:
- See appropriate POWER RACK & PINION article in STEERING.
- See appropriate ENGINE article in ENGINE MECHANICAL.
- See appropriate AUTOMATIC TRANSMISSION article in TRANSAXLES/TRANSMISSIONS.
- Clean the remaining disc brake system components to remove any traces of the contaminant.
- Remove the disc brake calipers, as appropriate, from the mounting brackets and support the calipers. Do Not disconnect the hydraulic brake flexible hoses from the calipers. See FRONT BRAKE CALIPER under REMOVAL & INSTALLATION.
- Inspect the disc brake caliper mounting/sliding hardware for the following conditions: Binding or seized hardware, distorted, worn, damaged or missing hardware components.
- Replace the caliper mounting/sliding hardware components as required. See FRONT DISC BRAKE HARDWARE under REMOVAL & INSTALLATION.
- Replace the contaminated disc brake pads as a complete axle set. See FRONT BRAKE PADS under REMOVAL & INSTALLATION.
- Check the thickness of each of the disc brake rotors. Make a determination for each brake rotor if the rotor can be REFINISHED and REMAIN ABOVE the minimum requirements. See BRAKE ROTOR THICKNESS MEASUREMENT in DISC BRAKE SYSTEM under TROUBLE SHOOTING. Does the disc brake rotor meet the minimum requirements for REFINISHING? If so, go to next step. If not, go to step 15 .
- Inspect each of the disc brake rotors for the following surface and wear conditions:
Braking Surface Conditions
- Heavy rust and/or pitting.
- Cracks and/or heat spots.
- Excessive blueing discoloration.
- .
Braking Surface Wear Conditions
- Deep or excessive scoring beyond maximum acceptable level.
- Lateral runout beyond maximum acceptable level
- Thickness variation beyond maximum acceptable level.
- Rotor exhibits one or more of the Braking Surface Conditions listed previously.
- Rotor is beyond the acceptable level in one or more of the Braking Surface Wear Conditions listed previously.
- Refinish the brake rotor. See BRAKE ROTOR REFINISHING under ADJUSTMENTS & INSPECTIONS. Inspect the brake rotor thickness. See BRAKE ROTOR SURFACE & WEAR INSPECTION in DISC BRAKE SYSTEM under TROUBLE SHOOTING. Were you able to REFINISH the brake rotor within the minimum requirements? If so, go to step 18 . If not, go to step 17 .
- Is the brake rotor at or below the DISCARD requirements? If so, go to step 17 . If not, go to next step.
- Inspect each of the disc brake rotors for the following surface and wear conditions:
Braking Surface Conditions
- Heavy rust and/or pitting.
- Cracks and/or heat spots.
- Excessive blueing discoloration.
Braking Surface Wear Conditions
- Deep or excessive scoring beyond maximum acceptable level.
- Lateral runout beyond maximum acceptable level.
- Thickness variation beyond maximum acceptable level.
- Rotor exhibits one or more of the Braking Surface Conditions listed previously.
- Rotor is beyond the acceptable level in one or more of the Braking Surface Wear Conditions listed previously.
- Replace the brake rotor. See FRONT BRAKE ROTOR under REMOVAL & INSTALLATION. After repairs are complete, go to next step.
- Install or connect components that were removed or disconnected during diagnosis. Did you complete the operation? If so, system is okay. If system is not okay, go to step 2 .
NOTE:
Support the brake caliper with heavy mechanic's wire, or equivalent, whenever it is separated from it's 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.