Test Description

WARNING: This page is about a different car, the 2004 Chevrolet Corvette. However, it is still accessible from the selected car via links, so may be relevant.

The numbers below refer to the step numbers on the diagnostic table:

9: Lubricant leaks from non-brake system components may come in contact with and contaminate brake system components.
10: Lubricant leaks from non-brake system components may come in contact with and contaminate brake system components.

13: Disc brake rotor thickness variation that exceeds the maximum acceptable level can cause brake pulsation.

17: Disc brake rotor thickness variation that exceeds the maximum acceptable level can cause brake pulsation.

20: Disc brake rotor assembled lateral runout (LRO) that exceeds the maximum acceptable level can lead to thickness variation.

Disc Brake System Diagnosis

Step	Action	Yes	No
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.
1	Were you sent here from a Brake Symptom table?	Go to Step 2	Go to Diagnostic Starting Point - Hydraulic Brakes
2	Visually inspect the disc brake pads for the following conditions: Refer to Brake Pad Inspection in Disc Brakes. Lining thickness below specifications Uneven and/or abnormal wear - edge-to-edge and/or side-to-side Looseness or damage - including pad hardware Evidence of contamination from an external substance Did you find any conditions to indicate a concern with any of the front and/or rear disc brake pads?	Go to Step 3	Go to Step 12
3	Are any of the front and/or rear disc brake pads contaminated?	Go to Step 8	Go to Step 4
4	Are any of the front and/or rear disc brake pads worn unevenly?	Go to Step 7	Go to Step 5
5	Are any of the front and/or rear disc brake pads and/or pad hardware loose or damaged?	Go to Step 7	Go to Step 6
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. Refer to Brake Pads Replacement - Front and/or Brake Pads Replacement - Rear in Disc Brakes. Did you complete the inspection and replacement?	Go to Step 12	-
7	NOTE: 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. IMPORTANT: Do NOT disconnect the hydraulic brake flex hoses from the calipers. Remove the front and/or rear disc brake calipers, as appropriate, from the mounting brackets and support the calipers. Refer to Brake Caliper Replacement - Front and/or Brake Caliper Replacement - Rear in Disc Brakes. Inspect the disc brake caliper mounting bracket and the mounting/sliding hardware for the following conditions: Refer to Disc Brake Mounting and Hardware Inspection - Front and/or Disc Brake Mounting and Hardware Inspection - Rear in Disc Brakes. Binding or seized hardware Worn, damaged or missing hardware components Loose, bent, cracked, or damaged caliper mounting bracket Replace components as required. Refer to the following procedures in Disc Brakes, as required: Brake Caliper Bracket Replacement - Front Brake Caliper Bracket Replacement - Rear Disc Brake Hardware Replacement - Front Disc Brake Hardware Replacement - Rear Replace the unevenly-worn, loose or damaged disc brake pads as a complete axle set. Refer to Brake Pads Replacement - Front and/or Brake Pads Replacement - Rear in Disc Brakes. Did you complete the inspection and replacement?	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. Refer to the following procedures as required: Brake Caliper Overhaul - Front or Brake Caliper Replacement - Front in Disc Brakes Brake Caliper Overhaul - Rear or Brake Caliper Replacement - Rear in Disc Brakes Brake Hose Replacement - Front Brake Hose Replacement - Rear Brake Pipe Replacement Did you find and correct the source of the leak causing contamination of the pads?	Go to Step 11	Go to Step 9
9	Inspect the wheel drive shaft outer seals for damage and evidence of a grease leak. Replace any wheel drive shaft seal that is found to be leaking grease which may be the source of the contamination to the pads. Refer to Wheel Drive Shaft Outer Joint and Seal Replacement in Wheel Drive Shafts. Did you find and correct the source of the leak causing contamination of the pads?	Go to Step 11	Go to Step 10
10	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. 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. Replace any components found to be leaking fluid which may be the source of the contamination to the pads. Did you find and correct the source of the leak causing contamination of the pads?	Go to Step 11	-
11	Clean the remaining disc brake system components to remove any traces of the contaminant. NOTE: 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. IMPORTANT: Do NOT disconnect the hydraulic brake flex hoses from the calipers. Remove the front and/or rear disc brake calipers, as appropriate, from the mounting brackets and support the calipers. Refer to Brake Caliper Replacement - Front and/or Brake Caliper Replacement - Rear in Disc Brakes. Inspect the disc brake caliper mounting/sliding hardware for the following conditions: Refer to Disc Brake Mounting and Hardware Inspection - Front and/or Disc Brake Mounting and Hardware Inspection - Rear in Disc Brakes. Binding or seized hardware Distorted, worn, damaged or missing hardware components Replace the caliper mounting/sliding hardware components as required. Refer to Disc Brake Hardware Replacement - Front and/or Disc Brake Hardware Replacement - Rear in Disc Brakes. Replace the contaminated disc brake pads as a complete axle set. Refer to Brake Pads Replacement - Front and/or Brake Pads Replacement - Rear in Disc Brakes. Did you complete the cleaning, inspection and replacement?	Go to Step 12	-
12	Check the thickness of each of the disc brake rotors. IMPORTANT: Make the following determination AND ANSWER the question INDIVIDUALLY for EACH rotor. Make a determination for each brake rotor if the rotor can be REFINISHED and REMAIN ABOVE the minimum requirements. Refer to Brake Rotor Thickness Measurement in Disc Brakes.Does the disc brake rotor meet the minimum requirements for REFINISHING?	Go to Step 13	Go to Step 16
13	IMPORTANT: Perform the following inspection AND ANSWER the question INDIVIDUALLY for EACH rotor. Inspect each of the disc brake rotors for thickness variation that exceeds the maximum acceptable level. Refer to Brake Rotor Thickness Variation Measurement in Disc Brakes.Does the brake rotor exhibit thickness variation that exceeds the maximum acceptable level?	Go to Step 15	Go to Step 14
14	Inspect each of the disc brake rotors for the following surface and wear conditions: Refer to Brake Rotor Surface and Wear Inspection in Disc Brakes. Heavy rust and/or pitting Cracks and/or heat spots Excessive blueing discoloration Deep or excessive scoring beyond maximum acceptable level IMPORTANT: Make the following determination AND ANSWER the question INDIVIDUALLY for EACH rotor. 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. Does the brake rotor require REFINISHING?	Go to Step 15	Go to Step 20
15	Refinish the brake rotor. Refer to Brake Rotor Refinishing in Disc Brakes. Inspect the brake rotor thickness. Refer to Brake Rotor Thickness Measurement in Disc Brakes. Were you able to REFINISH the brake rotor within the minimum requirements?	Go to Step 20	Go to Step 19
16	Is the brake rotor at or below the DISCARD requirements?	Go to Step 19	Go to Step 17
17	IMPORTANT: Perform the following inspection AND ANSWER the question INDIVIDUALLY for EACH rotor. Inspect each of the disc brake rotors for thickness variation that exceeds the maximum acceptable level. Refer to Brake Rotor Thickness Variation Measurement in Disc Brakes.Does the brake rotor exhibit thickness variation that exceeds the maximum acceptable level?	Go to Step 19	Go to Step 18
18	Inspect each of the disc brake rotors for the following surface and wear conditions: Refer to Brake Rotor Surface and Wear Inspection in Disc Brakes. Heavy rust and/or pitting Cracks and/or heat spots Excessive blueing discoloration Deep or excessive scoring beyond maximum acceptable level IMPORTANT: Make the following determination AND ANSWER the question INDIVIDUALLY for EACH rotor. 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. Does the brake rotor require REPLACEMENT?	Go to Step 19	Go to Step 20
19	IMPORTANT: 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. Replace the brake rotor. Refer to Brake Rotor Replacement - Front or Brake Rotor Replacement - Rear in Disc Brakes.Did you complete the replacement?	Go to Step 22	-
20	IMPORTANT: Perform the following inspection AND ANSWER the question INDIVIDUALLY for EACH rotor. Inspect each of the disc brake rotors for assembled lateral runout (LRO) that exceeds the maximum acceptable level. Refer to Brake Rotor Assembled Lateral Runout (LRO) Measurement in Disc Brakes.Does the brake rotor exhibit assembled LRO that exceeds the maximum acceptable level?	Go to Step 21	Go to Step 22
21	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 (LRO) Correction in Disc Brakes. Did you complete the operation?	Go to Step 22	-
22	Install or connect components that were removed or disconnected during diagnosis. Did you complete the operation?	Disc Brake System OK Return to Symptom Table	-