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Disc Brake System

WARNING: This page is about a different car, the 2003 Buick Regal, 2003 Buick Century, 2002 Buick Regal, and 2002 Buick Century. However, it is still accessible from the selected car via links, so may be relevant.
  1. Were you sent here from a SYMPTOMS test under TROUBLE SHOOTING? If so, go to next step. If not, go to DIAGNOSTIC STARTING POINT - HYDRAULIC BRAKES  under TROUBLE SHOOTING.
  2. 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).
    Did you find any conditions to indicate a concern with any of the (front and/or rear) disc brake pads? If so, go to next step. If not, go to step  12 .
  3. Are any of the (front and/or rear) disc brake pads contaminated? If so, go to step  8 . If not, go to next step.
  4. Are any of the (front and/or rear) disc brake pads worn unevenly? If so, go to step  7 . If not, go to next step.
  5. Are any of the (front and/or rear) disc brake pads and/or pad hardware loose or damaged? If so, go to step  7 . If not, go to next step.
  6. 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. SeeDISC PADS (FRONT)  and DISC PADS (REAR)  , if equipped, under REMOVAL & INSTALLATION. Did you complete the inspection and replacement? If so, go to step  12 .
  7. Remove the (front and/or rear) disc brake calipers (as appropriate) from the mounting brackets and support the calipers. Do NOT disconnect the hydraulic brake flex hoses from the calipers. See CALIPER (FRONT)  and BRAKE CALIPER (REAR)  under REMOVAL & INSTALLATION. 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.
    See DISC MOUNTING AND HARDWARE INSPECTION (FRONT)  and DISC MOUNTING AND HARDWARE INSPECTION (REAR)  under ADJUSTMENTS & INSPECTIONS. Replace components as required: Replace the unevenly-worn, loose or damaged disc brake pads as a complete axle set. See DISC PADS (FRONT)  and DISC PADS (REAR)  , if equipped, under REMOVAL & INSTALLATION. Did you complete the inspection and replacement? If so, go to step  12 .
  8. 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. 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.
    9. NOTE: Lubricant leaks from non-brake system components may come in contact with and contaminate brake system, components.
  9. 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 AXLE SHAFTS article in DRIVELINE/AXLES. 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.
    10. NOTE: Lubricant leaks from non-brake system components may come in contact with and contaminate brake system, components.
  10. 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. See the following procedures:
    • For steering faults, see appropriate POWER STEERING SYSTEM article in STEERING.
    • For engine faults, see appropriate article in ENGINES.
    • For transmission faults, see appropriate article in TRANSMISSIONS.
    Did you find and correct the source of the leak causing contamination of the pads? If so, go to next step.
  11. Clean the remaining disc brake system components to remove any traces of the contaminant. Remove the (front and/or rear) disc brake calipers (as appropriate) from the mounting brackets and support the calipers. Do NOT disconnect the hydraulic brake flex hoses from the calipers. See CALIPER (FRONT)  and BRAKE CALIPER (REAR)  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.
    See DISC MOUNTING AND HARDWARE INSPECTION (FRONT)  and DISC MOUNTING AND HARDWARE INSPECTION (REAR)  under ADJUSTMENTS & INSPECTIONS. Replace the caliper mounting/sliding hardware components as required. See DISC HARDWARE REPLACEMENT (FRONT)  and DISC HARDWARE REPLACEMENT (REAR)  under REMOVAL & INSTALLATION. Replace the contaminated disc brake pads as a complete axle set. DISC PADS (FRONT)  and BRAKE CALIPER (REAR)  under REMOVAL & INSTALLATION. Did you complete the cleaning, inspection and replacement? If so, go to next step.
    12. NOTE: Disc brake rotor shields/backing plates that come in contact with disc brake rotors may cause brake system noise.
  12. Visually inspect each of the rear disc brake rotor shields/backing plates for evidence of contact with the brake rotors. Are any of the rear brake rotor shields/backing plates contacting the brake rotors? If so, go to next step. If not, go to step  14 .
  13. Repair or replace the rear disc brake rotor shields/backing plates as required. Did you complete the repair or replacement? If so, go to next step.
  14. 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 ROTOR THICKNESS MEASUREMENT  under ADJUSTMENTS & INSPECTIONS. Does the disc brake rotor meet the minimum requirements for refinishing? If so, go to next step. If not, go to step  17 .
  15. Inspect each of the disc brake rotors for the following surface and wear conditions for braking surface:
    • 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.
    Make a determination for each brake rotor if the rotor requires refinishing based upon the results of the inspection. If the brake rotor exhibits any of the following conditions, it requires refinishing:
    • 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.
    Does the brake rotor require refinishing? If so, go to next step. If not, go to step  20 .
  16. Refinish the brake rotor. See BRAKE ROTOR REFINISHING  under SERVICING. Inspect the brake rotor thickness. See ROTOR THICKNESS MEASUREMENT  under ADJUSTMENTS & INSPECTIONS. Were you able to refinish the brake rotor within the minimum requirements? If so, go to step  20 . If not, go to step  19 .
  17. Is the brake rotor at or below the discard requirements? If so, go to step  19 . If not, go to next step.
  18. Inspect each of the disc brake rotors for the following:

    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
    Make a determination for each brake rotor if the rotor requires replacement based upon the results of the inspection. If a brake rotor exhibits any of the following conditions, it requires replacement:
    • 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.
    Does the brake rotor require replacement? If so, go to next step. If not, go to step  20 .
  19. Replace the brake rotor. See BRAKE ROTOR (FRONT)  and BRAKE ROTOR (REAR)  under REMOVAL & INSTALLATION. After repairs are complete, go to next step.
  20. Install or connect components that were removed or disconnected during diagnosis. Did you complete the operation? Then system is okay. If system is not okay, go to step  2 .
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