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 correctly. You will be directed by the appropriate Symptom table to go to other brake system diagnostic tables as appropriate.

Were you sent here from a Brake Symptom table?

Go to Step 2

Go to Diagnostic Starting Point - Hydraulic Brakes

Visually inspect the brake pads for the following conditions:

Refer to Brake Pad Inspection .

Did you find any conditions to indicate a concern with any of the front and/or rear brake pad?

Go to Step 3

Go to Step 12

Are any of the front and/or rear brake pads contaminated?

Go to Step 8

Go to Step 4

Are any of the front and/or rear brake pads worn unevenly?

Go to Step 7

Go to Step 5

Are any of the front and/or rear brake pads and/or brake pad hardware loose or damaged?

Go to Step 7

Go to Step 6

1. Remove and inspect the worn brake pads for glazing, looseness, heat spots or damage.
2. Replace the worn brake pads as a complete axle set. Refer to Front Disc Brake Pads Replacement and/or Rear Disc Brake Pads Replacement .

Did you complete the inspection and replacement?

Go to Step 12

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Notice: Support the brake caliper with heavy mechanic 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 brake calipers.

1. Remove the front and/or rear brake calipers, as appropriate, from the brake caliper anchor plates and support the brake calipers. Refer to Front Brake Rotor Replacement or Rear Brake Rotor Replacement .
2. Inspect the brake caliper anchor plate and the mounting/sliding hardware for the following conditions:

•	Binding or seized brake caliper slides

•	Worn, damaged or missing components

•	Loose, bent, cracked, or damaged brake caliper anchor plate

3. Replace components as required. Refer to the following procedures as required:

•	Front Brake Caliper Replacement .

•	Rear Brake Caliper Replacement .

4. Replace the unevenly-worn, loose or damaged brake pads as a complete axle set. Refer to Front Disc Brake Pads Replacement and/or Rear Disc Brake Pads Replacement .

Did you complete the inspection and replacement?

Go to Step 12

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1. Inspect the brake calipers, brake hoses and brake pipes for evidence of an external brake fluid leak.
2. Replace any components found to be leaking brake fluid. Refer to the following procedures as required:

•	Front Brake Caliper Overhaul or Front Brake Caliper Replacement .

•	Rear Brake Caliper Overhaul or Rear Brake Caliper Replacement .

•	Front Brake Hose Replacement .

•	Rear Brake Hose Replacement .

•	Brake Pipe Replacement Caution .

Did you find and correct the source of the leak causing contamination of the brake pads?

Go to Step 11

Go to Step 9

1. Inspect the wheel drive shaft outer seals for damage and evidence of a grease leak.
2. Replace any wheel drive shaft seal that is found to be leaking grease which may be the source of the contamination to the brake pads. Refer to Wheel Drive Shaft Outer Joint and Boot Replacement .

Did you find and correct the source of the leak causing contamination of the brake pads?

Go to Step 11

Go to Step 10

1. Clean the remaining disc brake system components to remove any traces of the contaminant.

Notice: Support the brake caliper with heavy mechanic 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 brake calipers.

2. Remove the front and/or rear brake calipers, as appropriate, from the brake caliper anchor plates and support the brake calipers. Refer to Front Brake Rotor Replacement and/or Rear Brake Rotor Replacement .
3. Inspect the brake caliper anchor plate/sliding hardware for the following conditions:

•	Binding or seized hardware

•	Distorted, worn, damaged or missing hardware components

4. Replace the brake calipers as required. Refer to Front Brake Caliper Replacement or Rear Brake Caliper Replacement .
5. Replace the contaminated brake pads as a complete axle set. Refer to Front Disc Brake Pads Replacement and/or Rear Disc Brake Pads Replacement .

Did you complete the cleaning, inspection and replacement?

Go to Step 11

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Visually inspect each of the rear disc brake disc shields/backing plates for evidence of contact with the brake discs.

Are any of the brake disc shields/backing plates contacting the brake discs?

Go to Step 12

Go to Step 13

Repair or replace the disc brake disc shields/backing plates as required. Refer to Rear Disc Brake Backing Plate Replacement .

Did you complete the repair or replacement?

Go to Step 13

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1. Inspect the thickness of each of the brake discs.

Important: Make the following determination AND ANSWER the question INDIVIDUALLY for EACH brake disc.

2. Make a determination for each brake disc if the brake disc can be REFINISHED and REMAIN ABOVE the minimum requirements.

Refer to Brake Rotor Thickness Measurement .

Does the brake disc meet the minimum requirements for REFINISHING?

Go to Step 14

Go to Step 17

Important: Perform the following inspection AND ANSWER the question INDIVIDUALLY for EACH brake disc.

Inspect each of the brake discs for thickness variation that exceeds the maximum acceptable level. Refer to Brake Rotor Thickness Variation Measurement .

Does the brake disc exhibit thickness variation that exceeds the maximum acceptable level?

Go to Step 16

Go to Step 15

1. Inspect each of the brake discs for the following surface and wear conditions:

Refer to Brake Rotor Surface and Wear Inspection .

•	Heavy rust and/or pitting

•	Cracks and/or heat spots

•	Too much blueing, discoloration

•	Deep or greater than desired scoring beyond maximum acceptable level

Important: Make the following determination AND ANSWER the question INDIVIDUALLY for EACH brake disc.

2. Make a determination for each brake disc if the brake disc requires refinishing based upon the results of the inspection.

If the brake disc exhibits any of the conditions listed previously, it requires refinishing.

Does the brake disc require REFINISHING?

Go to Step 16

Go to Step 21

1. Refinish the brake disc. Refer to Brake Rotor Refinishing .
2. Inspect the brake disc thickness. Refer to Brake Rotor Thickness Measurement .

Were you able to REFINISH the brake disc within the minimum requirements?

Go to Step 21

Go to Step 20

Is the brake disc at or below the DISCARD requirements?

Go to Step 20

Go to Step 18

Important: Perform the following inspection AND ANSWER the question INDIVIDUALLY for EACH brake disc.

Inspect each of the brake discs for thickness variation that exceeds the maximum acceptable level. Refer to Brake Rotor Thickness Variation Measurement .

Does the brake disc exhibit thickness variation that exceeds the maximum acceptable level?

Go to Step 20

Go to Step 19

1. Inspect each of the brake discs for the following surface and wear conditions:

Refer to Brake Rotor Surface and Wear Inspection .

•	Heavy rust and/or pitting

•	Cracks and/or heat spots

•	Too much blueing, discoloration

•	Deep or greater than desired scoring beyond maximum acceptable level

Important: Make the following determination AND ANSWER the question INDIVIDUALLY for EACH brake disc.

2. Make a determination for each brake disc if the brake disc requires replacement based upon the results of the inspection.

If the brake disc exhibits any of the conditions listed previously, it requires replacement.

Does the brake disc require REPLACEMENT?

Go to Step 20

Go to Step 21

Important: Whenever a brake disc is replaced, the assembled lateral runout (LRO) of the brake disc must be measured to make sure optimum performance of the disc brakes.

Replace the brake disc. Refer to Front Brake Rotor Replacement or Rear Brake Rotor Replacement .

Did you complete the replacement?

Go to Step 23

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Important: Perform the following inspection AND ANSWER the question INDIVIDUALLY for EACH brake disc.

Inspect each of the brake discs for assembled lateral runout (LRO) that exceeds the maximum acceptable level. Refer to Brake Rotor Assembled Lateral Runout Measurement .

Does the brake disc exhibit assembled LRO that exceeds the maximum acceptable level?

Go to Step 22

Go to Step 23

Correct the LRO for each brake disc that was determined to have LRO exceeding the maximum acceptable level. Refer to Brake Rotor Assembled Lateral Runout Correction .

Did you complete the operation?

Go to Step 23

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Install or connect components that were removed or disconnected during diagnosis.

Did you complete the operation?

Disc Brake System OK

Return to Symptom Table

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