Brake Systems: Shoes
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 |
|
NOTE:
Identify 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 | |
|
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 shoes that are tapered by design. Refer to specific vehicle application. If not normal, require correction of cause and replacement of shoes.
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| Thickness of one shoe is greater than opposite shoe in the same drum (uneven wear) | Replacement of friction material not suggested or required. Further inspection required. | |
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NOTE:
Uneven shoe thickness is normal on some vehicles. Refer to specific vehicle applications.
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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 |