JEEP CHEROKEE 1988 Service Repair Manual
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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.
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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
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Condition Code Procedure
Bent .................... A ............ Require replacement.
Broken .................. A ........ ( 1) Require replacement.
Loose ................... B ... Require repair or replacement
of affected component.
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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.
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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
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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.
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WHEEL CYLINDERS
You are not required to replace or rebuild wheel cylinders in
axle sets. However, when rebuilding or replacing a wheel cylinder due
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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
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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 non-
repairable) ............ 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.
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(3) - Inspect for conditions related to wheel cylinder.
( 4) - Leaking is defined as a drop or more. Dampness is normal.
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WIRING HARNESSES
NOTE: Copied from Electrical UIGs.
WIRING HARNESS INSPECTION
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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.
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Page 316 of 1378
BRAK E S YSTE M
1988 J e ep C hero ke e
1988 BRAKES
Jeep - Brake System
Cherokee, Comanche, Grand Wagoneer, Wagoneer, Wrangler
DESCRIPTION
DISC BRAKES
Floating caliper disc brake assembly uses a single piston
caliper which "floats" on 2 bolts. As brake pedal is depressed,
hydraulic pressure is passed through a proportioning valve to brake
caliper piston.
This force is transmitted to inboard brake pad, forcing it
against braking surface of rotor. Pressure then moves outer caliper
housing and pad inward on caliper mounting bolts, thus forcing outer
pad against outer braking surface of rotor.
DRUM BRAKES
Self-centering type system uses primary and secondary brake
shoes with cable operated automatic adjusters. Brake shoe anchor is
located at upper end of shoes above wheel cylinder. Single double
acting brake cylinder is used.
MASTER CYLINDER - EXCEPT GRAND WAGONEER
The Delco Quick Take-Up master cylinder is used with systems
utilizing low drag calipers. Master cylinder includes a quick take-up
valve which delivers a large volume of fluid, at low pressure, upon
initial brake application.
MASTER CYLINDER - GRAND WAGONEER
Bendix and Delco-Moraine tandem dual piston master cylinders
are single casting type with front and rear pistons and a separate
reservoir and outlet for each piston. Primary piston is operated by
push rod connected to brake pedal. Secondary piston is operated by
primary piston.
ADJUSTMENTS
NOTE: For Hub, Bearing and Axle Shaft Removal, Installation and
Adjustment information, see appropriate DRIVE AXLES article.
DISC BRAKE PADS
Automatic adjustment is provided by outward relocation of
piston as lining wears.
DRUM BRAKE SHOES
1) Rear brake shoes adjust automatically as brakes are
applied while vehicle is operated in reverse. Drive vehicle in reverse
applying brakes firmly 10-15 times, between each reverse brake
application, drive vehicle forward and press brakes firmly.
2) Manual adjustment is required if shoes have been removed
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and reinstalled. Brake shoes can be manually adjusted by rotating
adjuster screw. Remove access slot cover.
3) Using a small blade screwdriver, push in on adjustment
lever to separate from adjustment screw. Turn adjustment screw until
brake drum is locked tight. Back screw off until wheel rotates freely.
If brake drum is to be removed, back off adjustment screw several
notches for adequate clearance.
HEIGHT SENSING PROPORTIONING VALVE - COMANCHE
NOTE: Anytime adjustment is required the lever bushing must be
replaced.
Adjustment must be made on a drive-on lift or a flat level
surface with vehicle at curb weight. Remove height sensing
proportioning valve shaft nut and washer. Disconnect valve lever and
remove spring. Remove and discard bushing.
Rotate valve shaft to permit installation and proper
alignment of valve adjusting gauge (J-35853-2).
NOTE: The gauge (J-35853-2) must be properly seated on the "D"
shape of the shaft and the lower mounting bolt of the valve.
See Fig. 2. Also, all linkage components, excluding the
spring, must be connected to the axle housing before
installation of bushing.
Place lever bushing in lever. Using bushing installation
tool (J-35853-1) press bushing along with lever onto valve shaft.
Remove lever and adjusting to (J-35853-2) then install the spring.
Install lever, washer and retaining nut. Tighten retaining nut to 100
Inch-lbs. (11 N.m). Connect spring to lever arm.
Fig. 1: Exploded View of Height Sensing Proportioning Valve
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Fig. 2: Front and Side View of Valve Shaft
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Fig. 3: Back View of Valve Shaft
PARKING BRAKE - EXCEPT GRAND WAGONEER
1) Adjust rear brakes. Check cable for binds, kinks or frayed
condition. Replace cable (if necessary). Apply and release parking
brake 5 times.
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2) On all models except Wrangler, place parking brake lever
in fifth notch. Raise vehicle. Using Adjustment Gauge (J-34651), apply\
a torque of 50-55 INCH lbs. (5-6 N.m). See Fig. 4.
3) Adjust nut on parking brake cable equalizer until pointer
is in Blue section of gauge. Apply and release parking brake cable 5
times. Check adjustment and readjust cable (if necessary).
Fig. 4: Parking Brake Adjustment (Except Grand Wagoneer)
Courtesy of American Motors/Jeep Corp.
PARKING BRAKE - GRAND WAGONEER