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Disc Brake System

WARNING: This page is about a different car, the 2003 GMC Sonoma, 2003 GMC Jimmy, 2003 Chevrolet S10 Pickup, and 2003 Chevrolet Blazer. However, it is still accessible from the selected car via links, so may be relevant.
  1. Were you sent here from SYMPTOMS - HYDRAULIC BRAKES  under TROUBLE SHOOTING? If so, go to the next step. If not, go to 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 the 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 the 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 the 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 the 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. See BRAKE PADS - FRONT DUAL PISTON CALIPER  or BRAKE PADS - FRONT SINGLE PISTON CALIPER  and/or BRAKE PADS - REAR  under REMOVAL & INSTALLATION. Did you complete the inspection and replacement? If so, go to step  12.
    1. 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 BRAKE PADS - FRONT DUAL PISTON CALIPER  or BRAKE PADS - FRONT SINGLE PISTON CALIPER  and/or BRAKE PADS - REAR  under REMOVAL & INSTALLATION.
    2. 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/or DISC MOUNTING AND HARDWARE INSPECTION - REAR  under ADJUSTMENT & INSPECTION.

    3. Replace components as required. See the following procedures: under REMOVAL & INSTALLATION.
    4. Replace the unevenly-worn, loose or damaged disc brake pads as a complete axle set. See BRAKE PADS - FRONT DUAL PISTON CALIPER , BRAKE PADS - FRONT SINGLE PISTON CALIPER  and/or BRAKE PADS - REAR  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. See
  9. Inspect the wheel drive shaft outer seals (boots), if equipped, 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 SHAFT article under DRIVE AXLES. Inspect the rear axle seals for damage and evidence of a lubricant leak. Replace any rear axle seal that is found to be leaking lubricant which may be the source of the contamination to the pads. See appropriate DIFFERENTIAL article under DRIVE 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 the next step.
  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 appropriate POWER STEERING article under STEERING.
    • See appropriate ENGINE article under ENGINES.
    • See appropriate AUTOMATIC TRANSMISSION article under TRANSMISSIONS.
    Did you find and correct the source of the leak causing contamination of the pads? If so, go to the next step.
    1. 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 BRAKE CALIPER - FRONT SINGLE PISTON  or BRAKE CALIPER - FRONT DUAL PISTON  and/or BRAKE CALIPER - REAR  under REMOVAL & INSTALLATION.
    2. 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/or DISC MOUNTING AND HARDWARE INSPECTION - REAR  under ADJUSTMENT & INSPECTION.
    3. Replace the caliper mounting/sliding hardware components as required. See DISC BRAKE HARDWARE - FRONT DUAL PISTON  or DISC BRAKE HARDWARE - FRONT SINGLE PISTON  and/or DISC BRAKE HARDWARE - REAR  under REMOVAL & INSTALLATION.
    4. Replace the contaminated disc brake pads as a complete axle set. See , BRAKE PADS - FRONT DUAL PISTON CALIPER , BRAKE PADS - FRONT SINGLE PISTON CALIPER  and/or BRAKE PADS - REAR  under REMOVAL & INSTALLATION.
    Did you complete the cleaning, inspection and replacement? If so, go to the next step.
  12. Visually inspect each of the disc brake rotor shields/backing plates for evidence of contact with the brake rotors. Are any of the brake rotor shields/backing plates contacting the brake rotors? If so, go to the next step. If not, go to step  14.
  13. Repair or replace the disc brake rotor shield/backing plate as required. See DISC BRAKE SPLASH SHIELD - FRONT  and/or DISC BRAKE BACKING PLATE - REAR  under REMOVAL & INSTALLATION. After repairs are complete, go to the 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 DISC ROTOR THICKNESS MEASUREMENT  under ADJUSTMENTS & INSPECTION. Does the disc brake rotor meet the minimum requirements for refinishing? If so, go to the next step. If not, go to step  17.
  15. Inspect each of the disc brake rotors for surface and wear conditions: See DISC ROTOR SURFACE AND WEAR INSPECTION  under ADJUSTMENTS & INSPECTION. 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 conditions, it requires refinishing. Does the brake rotor require refinishing? If so, go to the next step. If not, go to step  20.
  16. Refinish the brake rotor. Inspect the brake rotor thickness. See DISC ROTOR THICKNESS MEASUREMENT  under ADJUSTMENTS & INSPECTION. 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 the next step.
  18. Inspect each of the disc brake rotors for the following surface and wear conditions: See DISC ROTOR SURFACE AND WEAR INSPECTION  under ADJUSTMENTS & INSPECTION. 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 conditions, it requires replacement. Does the brake rotor require replacement? If so, go to the next step. If not, go to step  20.
  19. Replace the brake rotor. See BRAKE ROTOR - FRONT  and/or BRAKE ROTOR - REAR  under REMOVAL & INSTALLATION. After repairs are complete, go to the next step.
  20. Install or connect components that were removed or disconnected during diagnosis. Did you complete the operation? If so, Disc Brake System is okay. If not, return to SYMPTOMS - HYDRAULIC BRAKES  under TROUBLE SHOOTING.
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