FRICTION MATERIAL
NOTE: Original Equipment Manufacturer (OEM) specifications
designate replacement at different thicknesses.
CAUTION: It is required that friction material be matched in axle
sets for consistent braking characteristics.
FRICTION MATERIAL INSPECTION
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Condition Code Procedure
Contaminated, for example,
fluid that leaked from
caliper, wheel cylinder,
or axle seal ........... A ........ ( 1) Require replacement.
Cracked through ......... B Require replacement.
Flaking or chunking ..... B Require replacement.
Glazed (shiny) .......... .. ........ No service suggested or
required.
Grooves or ridges ....... .. .... ( 2) No service suggested or
required.
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.
Surface cracking ........ .. ........ No service suggested or
required. Further inspection
may be necessary to determine
cause.
Tapered wear ............ B ........ ( 3) Suggest replacement.
Thickness of one pad is
greater than opposite pad
in the same caliper
(uneven wear) .......... .. .... ( 4) Replacement of friction
material not suggested or
required. Further inspection
required. See CALIPERS
and CALIPER HARDWARE.
Wear indicator device
(electronic) contacts
rotor .................. B ...... ( 5) Require replacement of
appropriate parts.
Wear indicator device
(mechanical) bent ....... .. .......... ( 6) Further inspection
required.
Wear indicator device
(mechanical) broken .... .. ......... ( 6) Further inspection
required.
reconditioning ......... B ........ (3) Require replacement.
Surface is rust-pitted .. B ....... Require reconditioning or
replacement of rotor according
to OEM specifications.
Surface is scored ....... B ... ( 4) Require reconditioning or
replacement of rotor according
to OEM specifications.
Thickness variation
(parallelism) exceeds OEM
specifications .......... B ....... Require reconditioning or
replacement of rotor according
to OEM specifications.
( 1) - Examples of severe corrosion are: composite plate
separated from friction surfaces and cooling fins
cracked or missing.
( 2) - Only applies to vehicles for which OEM "machine to"
specifications exist. If OEM does not supply "machine
to" specifications, the rotor may be worn to discard
specifications.
( 3) - If OEM does not supply "machine to" specifications,
you may machine to discard specifications.
( 4) - Scoring is defined as grooves or ridges in the friction
contact surface. Some vehicle manufacturers require
machining when scoring exceeds their allowable
specifications.
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SELF-ADJUSTING SYSTEMS
SELF-ADJUSTING SYSTEM INSPECTION \
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Condition Code Procedure
Bent .................... A ... Require repair or replacement
of bent part.
Broken .................. A ... Require repair or replacement
of broken part.
Inoperative ............. A ........... ( 1) Require repair or
replacement of inoperative
parts.
Missing ................. C .......... Require replacement of
missing part.
Star wheel does not turn
freely ................. A .. Require repair or replacement.
( 1) - Inoperative includes intermittent operation.
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SHOE HARDWARE
See BRAKE SHOE HARDWARE .
SHOES
See FRICTION MATERIAL .
SOCKETS
See BULB SOCKETS.
SPEED SENSORS (ELECTRONIC WHEEL AND VEHICLE)