Test Description

WARNING: This page is about a different car, the 2004 Pontiac Vibe. 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:

8: Lubricant leaks from non-brake system components may contaminate brake system components.

10: Disc brake rotor shields/backing plates that come in contact with disc brake rotors may cause brake system noise.

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 Pads Replacement - Front and/or Brake Pads Replacement - Rear , if equipped, in Disc Brakes. Lining thickness less than specifications Uneven or abnormal wear edge-to-edge or side-to-side Evidence of contamination from an external substance Looseness or damage to the pads or to the pad hardware 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 10
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 , if equipped, in Disc Brakes. Did you complete the inspection and replacement?	Go to Step 10	-
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 , if equipped, 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 , if equipped, in Disc Brakes. Binding or seized hardware Worn, damaged or missing hardware components Loose, bent, cracked, or damaged caliper mounting bracket Replace components as necessary. Refer to the following procedures in Disc Brakes: Brake Caliper Bracket Replacement - Front Disc Brake Hardware Replacement - Front Disc Brake Hardware Replacement - Rear , if equipped 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 , if equipped, in Disc Brakes. Did you complete the inspection and replacement?	Go to Step 12	-
8	Inspect the vehicle for an obvious source of a fluid leak. Repair as necessary. 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: Brake Caliper Overhaul - Front or Brake Caliper Replacement - Front in Disc Brakes Brake Caliper Overhaul - Rear or Brake Caliper Replacement - Rear , if equipped, in Disc Brakes Brake Hose Replacement - Front Brake Hose Replacement - Rear (Drum Brakes) or Brake Hose Replacement - Rear (Disc Brakes) Brake Pipe Replacement Did you find and correct the source of the leak causing contamination of the pads?	Go to Step 9	-
9	Clean the remaining disc brake system components in order 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 , if equipped, in Disc Brakes. Inspect the disc brake caliper mounting and the hardware for the following conditions. Refer to Disc Brake Mounting and Hardware Inspection - Front and/or Disc Brake Mounting and Hardware Inspection - Rear , if equipped, in Disc Brakes. Binding or seized hardware Distorted, worn, damaged or missing hardware components Replace the caliper hardware components as necessary. Refer to Disc Brake Hardware Replacement - Front and/or Disc Brake Hardware Replacement - Rear , if equipped, 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 , if equipped, in Disc Brakes. Did you complete the cleaning, inspection and replacement?	Go to Step 10	-
10	Visually inspect each of the disc brake rotor shields or backing plates, if equipped, for evidence of contact with the brake rotors. Are any of the brake rotor shields or backing plates contacting the brake rotors?	Go to Step 11	Go to Step 12
11	Repair or replace the disc brake rotor shields or backing plates as necessary. Refer to Disc Brake Splash Shield Replacement - Front and/or Disc Brake Backing Plate Replacement - Rear , if equipped, in Disc Brakes. Did you complete the repair or replacement?	Go to Step 12	-
12	Measure 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. 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. Measure 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 the 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. Does the brake rotor require REPLACEMENT?	Go to Step 19	Go to Step 20
19	IMPORTANT: Measure the assembled lateral runout (LRO) after replacing the brake rotor in order to ensure optimum performance of the disc brakes. Replace the brake rotor. Refer to Brake Rotor Replacement - Front or Brake Rotor Replacement - Rear , if equipped, in Disc Brakes.Did you complete the replacement?	Go to Step 20	-
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 assembled LRO exceed the maximum acceptable level?	Go to Step 21	Go to Step 22
21	Correct the brake rotor LRO. 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	-