Friction Material
NOTE:
Original Equipment Manufacturer (OEM) specifications designate replacement at different thicknesses. It is required that friction material be matched in axle sets for consistent braking characteristics.
| Condition | Code | Procedure |
|---|---|---|
| Contaminated, for example, fluid that leaked from caliper, wheel cylinder, or axle seal | A | Require replacement |
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NOTE:
Identity and repair cause of contamination prior to replacing friction material.
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| Cracked (Cracked through) | B | Require replacement |
| Cracked (Surface cracking) | No service suggested or required. Further inspection may be necessary to determine cause | |
| Flaking or chunking | B | Require replacement |
| Glazed (shiny) | No service suggested or required | |
| Grooves or ridges | No service suggested or required | |
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NOTE:
When reconditioning or replacing drums or rotors, replacement of friction material may be suggested depending on the severity of the grooves or ridges.
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| Out of Adjustment | B | Require Adjustment or Repair |
| Permanently attached hardware bent | A | Require replacement |
| Permanently attached hardware broken | A | Require replacement |
| Permanently attached hardware loose | A | Require replacement |
| Permanently attached hardware missing | C | Require replacement |
| Permanently attached hardware seized | A | Require repair or replacement |
| Rivets loose | B | Require replacement |
| Separating from backing | B | Require replacement |
| Shoe table or web bent | B | Require replacement |
| Shoe table or web cracked | A | Require replacement |
| Shoe table or web worn, affecting performance | A | Require replacement |
| Tapered wear | B | Suggest replacement |
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NOTE:
Some vehicles use pads that are tapered by design. Refer to specific vehicle application. If not normal, require correction of cause and replacement of pads.
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| Thickness of one pad is greater than opposite pad in the same caliper (uneven wear) | Replacement of friction material not suggested or required. Further inspection required. | |
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NOTE:
Uneven pad thickness is normal on some vehicles. Refer to specific vehicle applications.
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| Wear indicator device (electronic) contacts rotor | B | Require replacement of appropriate parts |
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NOTE:
The pad-wear indicator light may come on due to other electrical problems.
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| Wear indicator device (mechanical) bent | Further inspection required | |
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NOTE:
Explain to the customer that the purpose of the wear indicator is to alert him or her to check for friction wear. Wear indicators may be bent or broken. Therefore, the friction material must be measured. The need for friction material replacement is determined based upon the conditions stated in this section. Periodic inspection is Suggested.
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| Wear indicator device (mechanical) broken | Further inspection required | |
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NOTE:
Explain to the customer that the purpose of the wear indicator is to alert him or her to check for friction wear. Wear indicators may be bent or broken. Therefore, the friction material must be measured.
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| Wear indicator device (mechanical) broken | Further inspection required | |
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NOTE:
The need for friction material replacement is determined based upon the conditions stated in this section. Periodic inspection is suggested.
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| Wear indicator device (mechanical) contacts rotor | Further inspection required | |
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NOTE:
Explain to the customer that the purpose of the wear indicator is to alert him or her to check for friction wear. Wear indicators may be bent or broken. Therefore, the friction material must be measured. The need for friction material replacement is determined based upon the conditions stated in this section. Periodic inspection is Suggested.
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| Worn close to minimum specifications | 1 | Suggest replacement |
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NOTE:
When the part appears to be close to the end of its useful life, replacement may be suggested.
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| Worn to, or below minimum specifications | B | Require replacement |