Step
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Action
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Yes
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No
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DEFINITION: This diagnostic table is designed to diagnose ONLY the components of the DISC brake system in order to determine if the DISC brake system is operating properly. You will be directed by the appropriate Symptom table to go to other brake system diagnostic tables as appropriate.
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1
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Were you sent here from a Brake Symptom table?
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Go to
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Go to
Symptoms - Hydraulic Brakes
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2
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Visually inspect the disc brake pads for the following conditions:
Refer to
Brake Pad Inspection
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Lining thickness below specifications
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Uneven and/or abnormal wear - edge-to-edge and/or side-to-side
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Looseness or damage - including pad hardware
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Evidence of contamination from an external substance
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Did you find any conditions to indicate a concern with any of the front and/or rear disc brake pads?
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Go to
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Go to
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3
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Are any of the front and/or rear disc brake pads contaminated?
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Go to
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Go to
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4
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Are any of the front and/or rear disc brake pads worn unevenly?
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Go to
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Go to
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5
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Are any of the front and/or rear disc brake pads and/or pad hardware loose or damaged?
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Go to
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Go to
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6
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1.
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Remove and inspect the worn disc brake pads for glazing, looseness, heat spots or damage.
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Did you complete the inspection and replacement?
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Go to
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7
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1.
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Warning
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Suspend the brake caliper with a strong steel wire or similar. This applies every time the caliper is removed from its mounting with the brake hose is still attached. 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.
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Note
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Do NOT disconnect the hydraulic brake flex hoses from the calipers.
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Inspect the disc brake caliper mounting bracket and the mounting/sliding hardware for the following conditions:
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Binding or seized hardware
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Worn, damaged or missing hardware components
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Loose, bent, cracked, or damaged caliper mounting bracket
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3.
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Replace components as required. Refer to the following procedures, as required:
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Did you complete the inspection and replacement?
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Go to
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8
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1.
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Inspect the disc brake calipers, brake hoses and brake pipes for evidence of an external brake fluid leak.
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2.
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Replace any components found to be leaking brake fluid. Refer to the following procedures, as required:
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Did you find and correct the source of the leak causing contamination of the pads?
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Go to
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Go to
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1.
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Inspect the wheel drive shaft outer seals for damage and evidence of a grease leak.
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2.
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Replace any wheel drive shaft seal that is found to be leaking grease which may be the source of the contamination to the pads.
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Did you find and correct the source of the leak causing contamination of the pads?
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Go to
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Go to
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1.
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Inspect the automatic transmission cooling system lines, if equipped, for damage and evidence of an external fluid leak which may be the source of the contamination to the pads.
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2.
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Inspect the power steering system hoses for damage and evidence of an external fluid leak which may be the source of the contamination to the pads.
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3.
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Replace any components found to be leaking fluid which may be the source of the contamination to the pads.
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Did you find and correct the source of the leak causing contamination of the pads?
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Go to
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11
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1.
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Clean the remaining disc brake system components to remove any traces of the contaminant.
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Binding or seized hardware
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Distorted, worn, damaged or missing hardware components
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4.
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Replace the caliper mounting/sliding hardware components as required.
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Did you complete the cleaning, inspection and replacement?
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Go to
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Visually inspect each of the rear disc brake rotor shields/backing plates, if equipped, for evidence of contact with the brake rotors.
Are any of the brake rotor shields/backing plates contacting the brake rotors?
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Go to
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Go to
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13
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Repair or replace the disc brake rotor shields/backing plates as required. Refer to
Front Brake Shield Replacement (GNB)
Front Brake Shield Replacement (GNA)
or
Rear Brake Shield Replacement
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Did you complete the repair or replacement?
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Go to
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14
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1.
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Check the thickness of each of the disc brake rotors.
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2.
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Note
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Make the following determination AND ANSWER the question INDIVIDUALLY for EACH rotor.
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Make a determination for each brake rotor if the rotor can be REFINISHED and REMAIN ABOVE the minimum requirements.
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Refer to
Brake Rotor Thickness Measurement
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Does the disc brake rotor meet the minimum requirements for REFINISHING?
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Go to
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Go to
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Note
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Perform the following inspection AND ANSWER the question INDIVIDUALLY for EACH rotor.
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Inspect each of the disc brake rotors for thickness variation that exceeds the maximum acceptable level. Refer to
Brake Rotor Thickness Variation Measurement
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Does the brake rotor exhibit thickness variation that exceeds the maximum acceptable level?
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Go to
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Go to
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16
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Heavy rust and/or pitting
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Cracks and/or heat spots
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Excessive blueing discoloration
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Deep or excessive scoring beyond maximum acceptable level
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2.
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Note
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Make the following determination AND ANSWER the question INDIVIDUALLY for EACH rotor.
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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 conditions listed previously, it requires refinishing.
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Does the brake rotor require REFINISHING?
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Go to
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Go to
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17
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Were you able to REFINISH the brake rotor within the minimum requirements?
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Go to
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Go to
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18
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Is the brake rotor at or below the DISCARD requirements?
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Go to
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Go to
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Note
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Perform the following inspection AND ANSWER the question INDIVIDUALLY for EACH rotor.
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Inspect each of the disc brake rotors for thickness variation that exceeds the maximum acceptable level. Refer to
Brake Rotor Thickness Variation Measurement
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Does the brake rotor exhibit thickness variation that exceeds the maximum acceptable level?
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Go to
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Go to
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20
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Heavy rust and/or pitting
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Cracks and/or heat spots
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Excessive blueing discoloration
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Deep or excessive scoring beyond maximum acceptable level
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2.
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Note
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Make the following determination AND ANSWER the question INDIVIDUALLY for EACH rotor.
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Make a determination for each brake rotor if the rotor requires replacement based upon the results of the inspection.
If the brake rotor exhibits any of the conditions listed previously, it requires replacement.
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Does the brake rotor require REPLACEMENT?
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Go to
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Go to
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21
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Note
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Whenever a brake rotor is replaced, the assembled lateral runout (LRO) of the rotor must be measured to ensure optimum performance of the disc brakes.
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Replace the brake rotor. Refer to
Front Brake Rotor Replacement (J60, J61, J62)
or
Rear Brake Rotor Replacement (J60)
Rear Brake Rotor Replacement (J61, J62)
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Did you complete the replacement?
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Go to
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Note
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Perform the following inspection AND ANSWER the question INDIVIDUALLY for EACH rotor.
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Inspect each of the disc brake rotors for assembled LRO that exceeds the maximum acceptable level. Refer to
Brake Rotor Assembled Lateral Runout Measurement
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Does the brake rotor exhibit assembled LRO that exceeds the maximum acceptable level?
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Go to
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Go to
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23
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Correct the LRO for each brake rotor that was determined to have LRO exceeding the maximum acceptable level. Refer to
Brake Rotor Assembled Lateral Runout Measurement
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Did you complete the procedure?
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Go to
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24
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Install or connect any components that were removed or disconnected during diagnosis.
Did you complete the procedure?
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Disc Brake System OK
Return to Symptom Table
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