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 Step 2
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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 |
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 Step 3
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Go to Step 12
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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 Step 8
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Go to Step 4
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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 Step 7
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Go to Step 5
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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 Step 7
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Go to Step 6
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6
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1. |
Remove and inspect the worn disc brake pads for
glazing, looseness, heat spots or damage. |
Did you complete the inspection and replacement?
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Go to Step 12
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7
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Caution: 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.
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Note: |
Do NOT disconnect the hydraulic brake flex hoses
from the calipers. |
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1. |
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. |
Replace components as required. Refer to the
following procedures, as required: |
Did you complete the inspection and replacement?
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Go to Step 12
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8
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1. |
Inspect the disc brake calipers, brake hoses and
brake pipes for evidence of an external brake fluid leak. |
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2. |
Replace any components found to be leaking brake
fluid. Refer to the following procedures as required: |
Did you find and correct the source of the leak causing
contamination of the pads?
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Go to Step 11
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Go to Step 9
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9
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1. |
Inspect the wheel drive shaft outer seals for
damage and evidence of a grease leak. |
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2. |
Replace any wheel drive shaft seal that is found
to be leaking grease 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?
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Go to Step 11
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Go to Step 10
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10
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1. |
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. |
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. |
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?
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Go to Step 11
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11
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1. |
Clean the remaining disc brake system components
to remove any traces of the contaminant. |
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Caution: 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.
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Note: |
Do NOT disconnect the hydraulic brake flex hoses
from the calipers. |
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2. |
Remove the front and/or rear disc brake calipers,
as appropriate, from the mounting brackets and support the
calipers. Refer to and/or .
Front Brake Caliper Replacement |
• |
Binding or seized hardware |
• |
Distorted, worn, damaged or missing hardware
components |
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4. |
Replace the caliper mounting/sliding hardware
components as required. |
Did you complete the cleaning, inspection and replacement?
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Go to Step 12
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12
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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 Step 13
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Go to Step 14
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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 or
Rear Brake Shield Replacement .
Did you complete the repair or replacement?
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Go to Step 14
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14
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1. |
Check the thickness of each of the disc brake
rotors. |
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Note: |
Make the following determination AND ANSWER the
question INDIVIDUALLY for EACH rotor. |
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2. |
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 .
Does the disc brake rotor meet the minimum requirements for
REFINISHING?
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Go to Step 15
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Go to Step 18
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15
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Note: 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 .
Does the brake rotor exhibit thickness variation that exceeds the
maximum acceptable level?
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Go to Step 17
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Go to Step 16
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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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Note: |
Make the following determination AND ANSWER the
question INDIVIDUALLY for EACH rotor. |
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2. |
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?
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Go to Step 17
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Go to Step 22
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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 Step 22
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Go to Step 21
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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 Step 21
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Go to Step 19
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19
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Note: 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 .
Does the brake rotor exhibit thickness variation that exceeds the
maximum acceptable level?
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Go to Step 21
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Go to Step 20
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20
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• |
Heavy rust and/or pitting |
• |
Cracks and/or heat spots |
• |
Excessive blueing discoloration |
• |
Deep or excessive scoring beyond maximum
acceptable level |
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Note: |
Make the following determination AND ANSWER the
question INDIVIDUALLY for EACH rotor. |
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2. |
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?
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Go to Step 21
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Go to Step 22
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21
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Note: 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
Front Brake Rotor Replacement or
Rear Brake Rotor Replacement .
Did you complete the replacement?
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Go to Step 24
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22
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Note: Perform the following
inspection AND ANSWER the question INDIVIDUALLY for EACH rotor.
Inspect each of the disc brake rotors for assembled LRO that
exceeds the maximum acceptable level. Refer to
Brake Rotor Assembled Lateral Runout Measurement .
Does the brake rotor exhibit assembled LRO that exceeds the
maximum acceptable level?
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Go to Step 23
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Go to Step 24
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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 .
Did you complete the operation?
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Go to Step 24
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24
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Install or connect components that were removed or disconnected
during diagnosis.
Did you complete the operation?
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Disc Brake System OK
Return to Symptom Table
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