MODULATORS

See HYDRAULIC MODULATORS.

MOTORS

See ELECTRICAL PUMPS AND MOTORS.

PARKING BRAKE SWITCHES

See SWITCHES.

PARKING BRAKE SYSTEMS

NOTE: The parking brake is an integral part of the brake

system. It is important that the parking brake function properly when brake service is performed.

PARKING BRAKE SYSTEM INSPECTION

Condition Code Procedure
Attaching hardware
broken ................. A ... Require repair or replacement
of hardware.
Attaching hardware
missing ................ C .......... Require replacement of
hardware.
Attaching hardware not
functioning ............ A ... Require repair or replacement
of hardware.
Cable improperly
adjusted ............... B ....... Require cable adjustment.
Cable or individual
wires in the cable
are broken ............. A .... Require replacement of cable
assembly.
Cable sticking .......... A ...... Require cable lubrication.
Cable stuck inside conduit
and cannot be lubricated
so that parking brake
functions properly ..... A .... Require replacement of cable
assembly.
Inoperative (1) ......... A .......... Require replacement of
inoperative parts.
Parking brake
parts bent ............. B ... Require repair or replacement
of bent parts.
Parking brake
parts broken ........... A ... Require replacement of broken
parts.
Parking brake parts
missing ................ C .. Require replacement of missing
parts.
Threads damaged ......... A .. Require repair or replacement.
Threads stripped (threads
missing) ............... A ............ Require replacement.
(1) - Inoperative includes intermittent operation.

PADS

See FRICTION MATERIAL.

PEDAL TRAVEL SWITCHES

See SWITCHES.

PEDALS

See BRAKE PEDALS.

POWERMASTER

See HYDRO-BOOSTERS.

PUMPS

See ELECTRICAL PUMPS AND MOTORS.

PRESSURE DIFFERENTIAL SWITCHES

See SWITCHES.

PRESSURE SWITCHES

See SWITCHES.

RELAYS

NOTE: Copied from Electrical UIGs

RELAY INSPECTION

Condition Code Procedure
Attaching hardware
broken ................. A ... Require repair or replacement
of hardware.
Attaching hardware
missing ................ C .......... Require replacement of
hardware.
Attaching hardware not
functioning ............ A ... Require repair or replacement
of hardware.
Housing broken .......... A ............ Require replacement.
Housing cracked ......... 2 ............ Suggest replacement.
Inoperative (1) ......... A ............ Require replacement.
Missing ................. C ............ Require replacement.
Terminal broken ......... A .. Require repair or replacement.
Terminal burned,
affecting performance .. A ........... (2) Require repair or
replacement.
Terminal burned, not
affecting performance .. 2 .. Suggest repair or replacement.
Terminal corroded,
affecting performance .. A .. Require repair or replacement.
Terminal corroded, not
affecting performance .. 2 .. Suggest repair or replacement.
Terminal loose, affecting
performance ............ B .. Require repair or replacement.
Terminal loose, not
affecting performance .. 1 .. Suggest repair or replacement.
(1) - Inoperative includes intermittent operation or out of OEM
specification.
(2) - Determine cause and correct prior to repair or
replacement of part.

ROTORS

Determine the need to recondition based upon individual rotor conditions that follow. Friction material replacement does not require rotor reconditioning unless other justifications exist. DO NOT recondition new rotors unless they are being pressed or bolted onto an existing hub. It is not necessary to replace rotors in axle sets. However, when replacing or reconditioning a rotor due to the conditions that follow, you may suggest reconditioning of the other rotor on the same axle to eliminate uneven braking behavior.

Determine the need to replace based upon the individual rotor conditions that follow. Reconditioning is defined as machining and block sanding, or block sanding only. Block sanding is defined as using 120-150 grit sandpaper with moderate to heavy force for 60 seconds per side. Always wash rotors after servicing or before installing.

ROTOR INSPECTION

Condition Code Procedure
Corrosion affecting
structural integrity ... A ........ (1) Require replacement.
Cracked ................. B ............ Require replacement.
Hard spots .............. 2 ....... Suggest reconditioning or
replacement of rotor according
to OEM specifications.
Lateral runout (wobble)
exceeds OEM
specifications ......... B ............ Require re-indexing,
reconditioning, or replacement
according to specifications.
Measured thickness is less
than OEM discard
specifications ......... B ............ Require replacement.
Rotor thickness is less
than OEM "machine to"
specifications but thicker
than "discard at"
specifications, and the
rotor does not require
reconditioning ......... 1 ........ (2) Suggest replacement.
Rotor thickness will be
less than OEM "machine to"
specifications after
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.

SELF-ADJUSTING SYSTEMS

SELF-ADJUSTING SYSTEM INSPECTION

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.

SHOE HARDWARE

See BRAKE SHOE HARDWARE.

SHOES

See FRICTION MATERIAL.

SOCKETS

See BULB SOCKETS.

SPEED SENSORS (ELECTRONIC WHEEL AND VEHICLE)

NOTE: Copied Vehicle Speed Sensors from Engine UIGs & added Air Gap incorrect, loose, and wire lead misrouted. For "contaminated" removed coolant & fuel examples from note.

SPEED SENSOR INSPECTION

Condition Code Procedure
Air gap incorrect ....... B ....... (1) Require adjustment or
replacement.
Attaching hardware
missing ................ C .......... Require replacement of
hardware.
Attaching hardware
threads damaged ........ A ... Require repair or replacement
of hardware.
Attaching hardware
threads stripped
(threads missing) ...... A .. Require repair or replacement
of hardware.
Connector broken ........ A .. Require repair or replacement.
Connector (Weatherpack
type) leaking ........... A .. Require repair or replacement.
Connector melted ........ A ........... (2) Require repair or
replacement.
Connector missing ....... C ............ Require replacement.
Contaminated ............ A ........... (3) Require repair or
replacement.
Inoperative ............. B ........... (4) Require repair or
replacement. Further
inspection required.
Lead routing incorrect .. B ..... Require rerouting according
to vehicle manufacturer’s
specifications.
Leaking ................. A .. Require repair or replacement.
Loose ................... A .. Require repair or replacement.
Missing ................. C ............ Require replacement.
Resistance out of
specification .......... B .. Require repair or replacement.
Sensor housing cracked .. 2 ............ Suggest replacement.
Terminal broken ......... A .. Require repair or replacement.
Terminal burned,
affecting performance .. A ........... (2) Require repair or
replacement.
Terminal burned, not
affecting performance .. 2 .. Suggest repair or replacement.
Terminal corroded,
affecting performance .. A .. Require repair or replacement.
Terminal corroded, not
affecting performance .. 2 .. Suggest repair or replacement.
Terminal loose,
affecting performance .. B .. Require repair or replacement.
Terminal loose, not
affecting performance .. 1 .. Suggest repair or replacement.
Threads damaged ......... A .. Require repair or replacement.
Threads stripped
(threads missing) ...... A ............ Require replacement.
Wire lead conductors
exposed ................ B .. Require repair or replacement.
Wire lead corroded ...... A .. Require repair or replacement.
Wire lead misrouted ..... B . Require re-routing according to
vehicle manufacturer’s
specifications.
Wire lead open .......... A .. Require repair or replacement.
Wire lead shorted ....... A .. Require repair or replacement.
(1) - If a sensor is not adjustable, further inspection is
required to identify and correct cause.
(2) - Determine cause and correct prior to repair or
replacement of part.
(3) - Determine source of contamination, such as metal
particles or water. Require repair or replacement.
(4) - Inoperative includes intermittent operation or out of OEM
specification. Some components may be serviceable; check
for accepted cleaning procedure.

STEEL BRAKE LINES

STEEL BRAKE LINE INSPECTION

Condition Code Procedure
Attaching hardware
broken ................. A ... Require repair or replacement
of hardware.
Attaching hardware
missing ................ C .......... Require replacement of
hardware.
Attaching hardware not
functioning ............ A ... Require repair or replacement
of hardware.
Corroded, affecting
structural integrity ... A ............ Require replacement.
Fitting incorrect (for
example, compression
fitting) ............... B ............ Require replacement.
Flare type incorrect .... B .. Require repair or replacement.
Leaking ................. A .. Require repair or replacement.
Line material incorrect
(copper, etc.) ......... B ............ Require replacement.
Restricted .............. A ............ Require replacement.
Routed incorrectly ...... B ..... Require routing correction.
Rust-pitted ............. 1 ............ Suggest replacement.
Threads damaged ......... A .. Require repair or replacement.
Threads stripped
(threads missing) ...... A ............ Require replacement.

STOPLIGHT SWITCHES

See BRAKE STOPLIGHT SWITCHES.

SWITCHES

NOTE: Copied from Electrical UIGs & added "float saturated" from old fluid level sensor switches.

STEEL BRAKE LINE INSPECTION

Condition Code Procedure
Attaching hardware
broken ................. A ... Require repair or replacement
of hardware.
Attaching hardware
missing ................ C .......... Require replacement of
hardware.
Attaching hardware not
functioning ............ A ... Require repair or replacement
of hardware.
Binding, affecting
performance ............ A .. Require repair or replacement.
Binding, not affecting
performance ............ 2 .. Suggest repair or replacement.
Broken .................. A .. Require repair or replacement.
Burned, affecting
performance ............ A ........... (1) Require repair or
replacement.
Burned, not affecting
performance ............ 2 ........... (1) Suggest repair or
replacement.
Cracked, affecting
performance ............ A .. Require repair or replacement.
Cracked, not affecting
performance ............ 1 .. Suggest repair or replacement.
Float saturated ......... A ............ Require replacement.
Leaking ................. A .. Require repair or replacement.
Malfunctioning .......... A ........... (2) Require repair or
replacement.
Melted, affecting
performance ............ A ........... (1) Require repair or
replacement.
Melted, not affecting
performance ............ 2 ........... (1) Suggest repair or
replacement.
Missing ................. C ............ Require replacement.
Out of adjustment ....... B .. Require repair or replacement.
Terminal broken ......... A .. Require repair or replacement.
Terminal burned, affecting
performance ............ A ........... (1) Require repair or
replacement.
Terminal burned, not
affecting performance .. 2 .. Suggest repair or replacement.
Terminal corroded,
affecting performance .. A .. Require repair or replacement.
Terminal corroded, not
affecting performance .. 2 .. Suggest repair or replacement.
Terminal loose, affecting
performance ............ B .. Require repair or replacement.
Terminal loose, not
affecting performance .. 1 .. Suggest repair or replacement.
Won’t return ............ A .. Require repair or replacement.
Worn .................... 1 ............ Suggest replacement.
(1) - Determine cause and correct prior to repair or
replacement of part.
(2) - Includes inoperative, intermittent operation, or failure to
perform all functions.

TIRES

Consult the vehicle owner’s manual or vehicle placard for correct size, speed ratings, and inflation pressure of the original tires.

TIRE INSPECTION

Condition Code Procedure
Tire diameter incorrect,
affecting ABS or TCS ... A ............ Require replacement.
Tire pressure incorrect,
affecting ABS or TCS ... A .. Require repair or replacement.
Tire size incorrect,
affecting ABS or TCS ... A ............ Require replacement.

TOOTHED RINGS (TONE WHEEL)

NOTE: Copied from Drivetrain UIGs.

If the toothed ring requires replacement and cannot be replaced as a separate component, replace the assembly of which the ring is a part.

TOOTHED RING INSPECTION

Condition Code Procedure
Alignment incorrect ..... B ............... Require repair or
replacement.
Bent .................... B ............ Require replacement.
Contaminated, affecting
performance ............. A ........ Require repair. Identify
and correct cause.
Cracked ................. B ............ Require replacement.
Loose ................... A ............. Require replacement
of worn parts.
Missing ................. C ............ Require replacement.
Number of teeth
incorrect .............. B ............ Require replacement.
Teeth broken ............ A ............ Require replacement.
Teeth damaged, affecting
performance ............ A ............ Require replacement.

VACUUM BOOSTERS

VACUUM BOOSTER INSPECTION

Condition Code Procedure
Applies too much assist
(oversensitive) ........ A ............ Require replacement.
Attaching hardware
broken ................. A ... Require repair or replacement
of hardware.
Attaching hardware
missing ................ C .......... Require replacement of
hardware.
Attaching hardware not
functioning ............ A ... Require repair or replacement
of hardware.
Auxiliary vacuum pump
inoperative ............ A ........... (1) Require repair or
replacement.
Check valve grommet
deteriorated, affecting
performance ............ A .. Require replacement of grommet.
Check valve grommet
deteriorated, not
affecting performance .. 1 . Suggest replacement of grommet.
Check valve inoperative . A ........... (2) Require repair or
replacement.
Check valve leaking ..... A .... Require replacement of check
valve.
Check valve missing ..... C .... Require replacement of check
valve.
Check valve noisy ....... 2 ............ Suggest replacement.
Connector broken ........ A .. Require repair or replacement.
Connector (Weatherpack
type) leaking .......... A .. Require repair or replacement.
Connector melted ........ A ........ (3) Require replacement.
Connector missing ....... C ............ Require replacement.
Leaking ................. A ............ Require replacement.
Terminal burned, affecting
performance ............ A ........... (3) Require repair or
replacement.
Terminal burned, not
affecting performance .. 2 .. Suggest repair or replacement.
Terminal corroded,
affecting performance .. A .. Require repair or replacement.
Terminal corroded, not
affecting performance .. 2 .. Suggest repair or replacement.
Terminal loose, affecting
performance ............ B .. Require repair or replacement.
Terminal loose, not
affecting performance .. 1 .. Suggest repair or replacement.
Threads damaged ......... A .. Require repair or replacement.
Threads stripped (threads
missing) ............... A ............ Require replacement.
Vacuum hose filter
leaking ................ A .. Require replacement of filter.
Vacuum hose filter
restricted ............. A .. Require replacement of filter.
Wire lead burned ........ A .. Require repair or replacement.
Wire lead conductors
exposed ................ B .. Require repair or replacement.
Wire lead open .......... A .. Require repair or replacement.
Wire lead shorted ....... A .. Require repair or replacement.
(1) - Inoperative includes intermittent operation or out of
OEM specification.
(2) - Inoperative includes intermittent operation.
(3) - Determine cause and correct prior to replacement of part.

VACUUM HOSES

See HOSES.

VALVES

VALVE INSPECTION

Condition Code Procedure
Attaching hardware
broken ................. A ... Require repair or replacement
of hardware.
Attaching hardware
missing ................ C .......... Require replacement of
hardware.
Attaching hardware
not functioning ........ A ... Require repair or replacement
of hardware.
Leaking ................. B .. Require repair or replacement.
Linkage bent (rear
load valves) ........... A ... Require repair or replacement
of linkage.
Linkage broken (rear
load valves) ........... A ... Require repair or replacement
of linkage.
Linkage disconnected
(rear load valves) ..... C ... Require repair or replacement
of linkage.
Pressure out of
specification .......... B ...... Require adjustment. If not
possible, require replacement.
Seized .................. A ............ Require replacement.
Sticking ................ A .. Require repair or replacement.
Terminal burned,
affecting performance .. A ........... (1) Require repair or
replacement.
Terminal burned, not
affecting performance .. 2 .. Suggest repair or replacement.
Terminal corroded,
affecting performance .. A .. Require repair or replacement.
Terminal corroded, not
affecting performance .. 2 .. Suggest repair or replacement.
Terminal loose, affecting
performance ............ B .. Require repair or replacement.
Terminal loose, not
affecting performance .. 1 .. Suggest repair or replacement.
Threads damaged ......... A .. Require repair or replacement.
Threads stripped (threads
missing) ............... A ............ Require replacement.
Wire lead burned ........ A .. Require repair or replacement.
Wire lead conductors
exposed ................ B .. Require repair or replacement.
Wire lead open .......... A .. Require repair or replacement.
Wire lead shorted ....... A .. Require repair or replacement.
(1) - Determine cause and correct prior to repair or replacement
of part.

WHEEL ATTACHING HARDWARE

For conditions noted below, also check condition of wheel stud holes.

CAUTION: Proper lug nut torque is essential. Follow manufacturer’s torque specifications and tightening sequence. DO NOT lubricate threads unless specified by the vehicle manufacturer.

WHEEL ATTACHING HARDWARE INSPECTION

Condition Code Procedure
Bent .................... A ............ Require replacement.
Broken .................. A ........ (1) Require replacement.
Loose ................... B ... Require repair or replacement
of affected component.
Lug nut flats rounded ... A ..... Require replacement of nut.
Lug nut installed
backward ............... B ................. Require repair.
Lug nut mating surface
dished ................. A ..... Require replacement of nut.
Lug nut mating type
incorrect .............. B ..... Require replacement of nut.
Lug nut seized .......... A ...... Require replacement of nut
and/or stud.
Stud incorrect .......... B .... Require replacement of stud.
Threads damaged ......... A ... Require repair or replacement
of component with damaged
threads.
Threads stripped (threads
missing) ............... A .......... Require replacement of
component with stripped
threads.
(1) - Some manufacturers require replacement of all studs on
any wheel if two or more studs or nuts on the same wheel
are broken or missing.

WHEEL BEARINGS, RACES AND SEALS

NOTE: Grease seal replacement is required if seal is removed. You are not required to replace these components in axle sets. Determine the need to replace based upon the individual component conditions that follow.

WHEEL BEARINGS, RACES AND SEALS INSPECTION

Condition Code Procedure
Axle seal on drive axle
leaking ................ A . Require replacement of seal and
inspection of axle, bearing,
housing, and vent tube.
Bearing end-play exceeds
specifications ......... B .. Require adjustment of bearing,
if possible. If proper
adjustment cannot be obtained,
require replacement of bearing
assembly.
Bearing rollers, balls or
races are worn, pitted, or
feel rough when rotated as
an assembly ............ B .. Require replacement of bearing
assembly.
Seal leaking ............ A ...... (1) Require replacement of
seal and inspection of bearings.
Spindle worn ............ B .. Require replacement of spindle
and bearings.
(1) - Require inspection of mating and sealing surface and
repair or replace as necessary. Check vent. A plugged
vent may force fluid past the seal.

WHEEL CYLINDERS

You are not required to replace or rebuild wheel cylinders in axle sets. However, when rebuilding or replacing a wheel cylinder due to the conditions that follow, you may suggest rebuilding or replacement of the other wheel cylinder (on the same axle) for preventive maintenance, for example, the part is close to the end of its useful life. Determine the need to rebuild or replace based upon the individual wheel cylinder conditions that follow.

WHEEL CYLINDER INSPECTION

Condition Code Procedure
Attaching hardware bent . B ..... Require replacement of bent
parts.
Attaching hardware
broken ................. A ... Require repair or replacement
of hardware.
Attaching hardware
corroded, affecting
structural integrity ... A . Require replacement of corroded
parts.
Attaching hardware
loose .................. A .. Require repair or replacement.
Attaching hardware
missing ................ C .......... Require replacement of
hardware.
Attaching hardware not
functioning ............ A ... Require repair or replacement
of hardware.
Bleeder port damaged (if
non-repairable) ........ A ............ Require replacement.
Bleeder screw broken off
in wheel cylinder (if nonrepairable)
............ A ........ (1) Require replacement.
Bleeder screw plugged ... A ........... (1) Require repair or
replacement of bleeder screw.
Bleeder screw seized .... A ........ (2) Require replacement.
Bore corroded (pitted) .. B ............ Require replacement.
Bore grooved ............ A ............ Require replacement.
Bore oversized .......... B ............ Require replacement.
Dust boot missing ....... C ..... Require replacement of dust
boot.
Dust boot torn .......... A . (3) Require replacement of dust
boot.
Leaking ................. A ....... (4) Require rebuilding or
replacement.
Piston corroded, affecting
performance ............ B ... Require replacement of piston
and rebuilding or replacement
of wheel cylinder.
Piston finish worn off .. B ... Require replacement of piston
and rebuilding or replacement
of wheel cylinder.
Piston stuck in bore .... A .... Require replacement of wheel
cylinder.
Loose ................... B .. Require repair or replacement.
Threads damaged ......... A .. Require repair or replacement.
Threads stripped (threads
missing) ............... A ............ Require replacement.
(1) - Only required if the hydraulic system must be opened.
(2) - Seized is defined as bleeder screw that cannot be removed
after a practical attempt at removing. Only required if
the hydraulic system must be opened.
(3) - Inspect for conditions related to wheel cylinder.
(4) - Leaking is defined as a drop or more. Dampness is normal.

WIRING HARNESSES

NOTE: Copied from Electrical UIGs.

WIRING HARNESS INSPECTION

Condition Code Procedure
Application incorrect ... B .. Require repair or replacement.
Attaching hardware
broken ................. A ... Require repair or replacement
of hardware.
Attaching hardware
missing ................ C .......... Require replacement of
hardware.
Attaching hardware not
functioning ............ A ... Require repair or replacement
of hardware.
Connector broken ........ A .. Require repair or replacement.
Connector (Weatherpack
type) leaking .......... A .. Require repair or replacement.
Connector melted ........ A ........... (1) Require repair or
replacement.
Connector missing ....... C ............ Require replacement.
Insulation damaged,
conductors exposed ..... A .. Require repair or replacement.
Insulation damaged,
conductors not exposed . 1 ............ Suggest replacement.
Open .................... A .. Require repair or replacement.
Protective shield
(conduit) melted ....... 2 ........... (1) Suggest repair or
replacement.
Protective shield
(conduit) missing ...... 2 .. Suggest repair or replacement.
Resistance (voltage drop)
out of specification ... A .. Require repair or replacement.
Routed incorrectly ...... B ................. Require repair.
Secured incorrectly ..... B ................. Require repair.
Shorted ................. A .. Require repair or replacement.
Terminal broken ......... A .. Require repair or replacement.
Terminal burned, affecting
performance ............ A ........... (1) Require repair or
replacement.
Terminal burned, not
affecting performance .. 2 .. Suggest repair or replacement.
Terminal corroded,
affecting performance .. A .. Require repair or replacement.
Terminal corroded, not
affecting performance .. 2 .. Suggest repair or replacement.
Terminal loose, affecting
performance ............ B .. Require repair or replacement.
Terminal loose, not
affecting performance .. 1 .. Suggest repair or replacement.
Voltage drop out of
specification .......... A .. Require repair or replacement.
(1) - Determine cause and correct prior to repair or
replacement of part.