brake rotor JEEP CHEROKEE 1988 Service Repair Manual
[x] Cancel search | Manufacturer: JEEP, Model Year: 1988, Model line: CHEROKEE, Model: JEEP CHEROKEE 1988Pages: 1378, PDF Size: 19.9 MB
Page 120 of 1378
or the vehicle manufacturer's recommended service interval and must be
documented.
Some conditions indicate that service or part replacement is
required because the part in question is no longer providing the
function for which it is intended, does not meet a vehicle
manufacturer's design specification or is missing.
Example:
An exhaust pipe has corroded severely and has a hole in it
through which exhaust gases are leaking. Replacement of the
exhaust pipe in this case is required due to functional
failure.
Example:
A brake rotor has been worn to the point where it measures
less than the vehicle manufacturer's discard specifications.
Replacement of the rotor is required because it does not meet
design specifications.
Some conditions indicate that a service or part replacement
is suggested because the part is close to the end of its useful life
or addresses a customer's need, convenience or request. If a
customer's vehicle has one of these conditions, the procedure may be
only to suggest service.
Example:
An exhaust pipe is rusted, corroded or weak, but no leaks are
present. In this case, the exhaust pipe has not failed.
However, there is evidence that the pipe may need replacement
in the near future. Replacement of the pipe may be suggested
for the customer's convenience in avoiding a future problem.
Example:
The customer desires improved ride and/or handling, but the
vehicle's shocks or struts have not failed. In this case,
replacement may be suggested to satisfy the customer's
wishes. In this case, replacement of the shocks or struts may
not be sold as a requirement.
A customer, of course, has the choice of whether or not a
shop will service his or her vehicle. He or she may decide not to
follow some of your suggestions. When a repair is required, a MAP shop
must refuse partial service on that system if, in the judgment of the
service provider, proceeding with the work could create or continue an
unsafe condition. When a procedure states that required or suggested
repair or replacement is recommended, the customer must be informed of
the generally acceptable repair/replacement options whether or not
performed by the shop.
When presenting suggested repairs to the customer, you must
present the facts, allowing the customer to draw their own conclusions
and make an informed decision about how to proceed.
The following reasons may be used for required and suggested
services. These codes are shown in the "Code" column of the MAP
Uniform Inspection & Communications Standards that follow:
Reasons to Require Repair or Replacement
A - Part no longer performs intended purpose
B - Part does not meet a design specification (regardless of
performance)
C - Part is missing
NOTE: When a repair is required, the shop must refuse partial
Page 196 of 1378
Brake switch is an input device mounted above the brake
pedal. When brake pedal is operated, brake switch delivers an input
signal to the TCM. The TCM uses input signal for controlling No. 3
valve body solenoid for torque converter lock-up.
NEUTRAL SAFETY SWITCH
NOTE: Neutral safety switch may be referred to as park/neutral
safety switch or gear select switch.
Neutral safety switch is an input device mounted on the
transmission manual valve shaft. Neutral safety switch delivers an
input signal to TCM, indicating transmission manual valve gear
position.
SPEED SENSOR
Speed sensor, mounted in adapter housing or extension
housing, is an input device consisting of speed sensor rotor and speed
sensor. Speed sensor rotor is mounted on transmission output shaft.
Input signal is delivered from speed sensor to TCM with each
revolution of transmission output shaft. The TCM uses input signal for
controlling transmission operation.
THROTTLE POSITION SENSOR (TPS)
The TPS, mounted on throttle body, determines throttle
position and delivers an input signal to TCM. The TCM uses input
signal for controlling transmission upshifts and torque converter
lock-up.
SELF-DIAGNOSTIC SYSTEM
DIAGNOSTIC PROCEDURE
When performing vehicle diagnosis:
* Ensure transmission fluid level is correct and fluid is
neither contaminated nor aerated.
* Ensure shift cable is properly adjusted. Refer to the
appropriate TRANSMISSION SERVICING - A/T article in
this section.
* Ensure battery is fully charged.
* Perform visual inspection, ensuring all electrical
connections at transmission, TCM, throttle position sensor,
neutral safety switch, speed sensor and brake switch are
clean and properly installed.
* Perform TEST 1A - VERIFICATION OF THE COMPLAINT under TROUBLE
SHOOTING CHARTS in this article.
* Repair diagnostic trouble codes in order displayed.
* Always perform TEST 2A - VERIFICATION TEST after repair is
completed. See TEST 2A - VERIFICATION TEST under TROUBLE
SHOOTING CHARTS in this article.
RETRIEVING DIAGNOSTIC TROUBLE CODES
NOTE: Manufacturer recommends using Chrysler's Diagnostic Readout
Box-II (DRB-II) with proper cartridge for system diagnosis.
Other after-market scan tools may be used for system
diagnosis. The following procedure is for DRB-II scan tool
usage. Use manufacturer's instruction for operating the
Page 282 of 1378
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* B RAK E S YSTE M U NIF O RM IN SPEC TIO N G UID ELIN ES *
1 988 J e ep C hero ke e
GENERAL INFORMATION
Brake Systems - Motorist Assurance Program
Standards For Automotive Repair
All Makes & Models
CONTENTS
OVERVIEW OF MOTORIST ASSURANCE PROGRAM
OVERVIEW OF SERVICE REQUIREMENTS AND SUGGESTIONS
ACCELEROMETERS (G SENSOR OR LATERAL)
ACCUMULATORS
ANCHOR PINS
ANTI-LOCK BRAKE SYSTEMS
BACKING PLATES
BRAKE FLUID
BRAKE FRICTION MATERIAL
BRAKE PADS
BRAKE PEDALS
BRAKE SHOES
BRAKE SHOE HARDWARE
BRAKE STOPLIGHT SWITCHES
BULB SOCKETS
BULBS AND LEDS
CALIPER HARDWARE
CALIPERS
CONTROLLERS
DIGITAL RATIO AXLE CONTROLLERS AND BUFFERS (DRAC AND DRAB)
DISABLE SWITCHES
DRUMS
ELECTRICAL PUMPS AND MOTORS
ELECTRONIC CONTROLLERS
FLUID
FLUID LEVEL SENSOR SWITCHES
FOUR WHEEL DRIVE SWITCHES
FRICTION MATERIAL
G SENSORS
HOSES
HYDRAULIC MODULATORS
HYDRO-BOOSTERS
HYDRO-ELECTRIC BOOSTERS (POWERMASTER)
IGNITION DISABLE SWITCHES
LATERAL ACCELERATION SWITCHES
LEDS
LENSES
MASTER CYLINDERS
MODULATORS
MOTORS
PARKING BRAKE SWITCHES
PARKING BRAKE SYSTEMS
PADS
PEDAL TRAVEL SWITCHES
PEDALS
POWERMASTER
PUMPS
PRESSURE DIFFERENTIAL SWITCHES
PRESSURE SWITCHES
RELAYS
ROTORS
SELF-ADJUSTING SYSTEMS
Page 284 of 1378
satisfied with a repair transaction, the Motorist Assurance Program
offers mediation and arbitration through MAP/BBB-CARE and other non-
profit organizations. MAP conducted pilot programs in twelve states
before announcing the program nationally in October, 1998. During the
pilots, participating repair shops demonstrated their adherence to the
Pledge and Standards and agreed to follow the UICS in communicating
the results of their inspection to their customers. To put some
"teeth" in the program, an accreditation requirement for shops was
initiated. The requirements are stringent, and a self-policing method
has been incorporated which includes the "mystery shopping" of
outlets.
We welcome you to join us as we continue our outreach with
your support, both the automotive repair industry and your customers
will reap the benefits. Please visit MAP at our Internet site www.
motorist.org or contact us at:
1444 I Street, NW Suite 700
Washington, DC 20005
Phone (202) 712-9042 Fax (202) 216-9646
January 1999
MAP UNIFORM INSPECTION GENERAL GUIDELINES
OVERVIEW OF SERVICE REQUIREMENTS AND SUGGESTIONS
It is MAP policy that all exhaust, brake, steering,
suspension, wheel alignment, drive-line, engine performance and
maintenance, and heating, ventilation and air conditioning, and
electrical services be offered and performed under the standards and
procedures specified in these sections.
Before any service is performed on a vehicle, an inspection
of the appropriate system must be performed. The results of this
inspection must be explained to the customer and documented on an
inspection form. The condition of the vehicle and its components will
indicate what services/part replacements may be "Required" or
"Suggested". In addition, suggestions may be made to satisfy the
requests expressed by the customer.
When a component is suggested or required to be repaired or
replaced, the decision to repair or replace must be made in the
customer's best interest, and at his or her choice given the options
available.
This section lists the various parts and conditions that
indicate a required or suggested service or part replacement.
Although this list is extensive, it is not fully inclusive. In
addition to this list, a technician may make a suggestion. However,
any suggestions must be based on substantial and informed experience,
or the vehicle manufacturer's recommended service interval and must be
documented.
Some conditions indicate that service or part replacement is
required because the part in question is no longer providing the
function for which it is intended, does not meet a vehicle
manufacturer's design specification or is missing.
Example:
An exhaust pipe has corroded severely and has a hole in it
through which exhaust gases are leaking. Replacement of the
exhaust pipe in this case is required due to functional
failure.
Example:
A brake rotor has been worn to the point where it measures
less than the vehicle manufacturer's discard specifications.
Page 305 of 1378
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)
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
Page 321 of 1378
![JEEP CHEROKEE 1988 Service Repair Manual 1) Adjust rear brakes. Check cable for binds, kinks or frayed
condition. Replace cable (if necessary). Release parking brake. Loosen\
lock nuts at parking brake cable equalizer under vehicle](/img/16/57037/w960_57037-320.png "JEEP CHEROKEE 1988 Service Repair Manual 1) Adjust rear brakes. Check cable for binds, kinks or frayed
condition. Replace cable (if necessary). Release parking brake. Loosen\
lock nuts at parking brake cable equalizer under vehicle")
1) Adjust rear brakes. Check cable for binds, kinks or frayed
condition. Replace cable (if necessary). Release parking brake. Loosen\
lock nuts at parking brake cable equalizer under vehicle.
2) Tighten cables until wheels drag slightly when rotated by
hand. Loosen equalizer until wheels rotate freely and no drag is felt.
Tighten lock nuts and check operation of parking brake.
ROTOR SERVICING
RUNOUT
1) Measure rotor lateral runout by mounting a dial indicator
on support stand or steering spindle. Position indicator stylus so it
contacts center of rotor braking surface.
2) Zero indicator and turn rotor one revolution. Note
indicator reading. Runout must not exceed specification. See DISC
BRAKE ROTOR SPECIFICATIONS table. Refinish or replace rotor (if
necessary).
NOTE: Thickness of machined rotor must not be below minimum
thickness specification.
PARALLELISM
Measure rotor parallelism with a micrometer. Measure
thickness at 4 or more equally spaced points around rotor at
approximately 1" from edge of rotor. Variation must not exceed
specification. See DISC BRAKE ROTOR SPECIFICATIONS table. Refinish or
replace rotor (if necessary).
BRAKE SYSTEM BLEEDING
Hydraulic system bleeding is necessary any time air has been
introduced into system. Bleed brakes at all 4 wheels if master
cylinder lines have been disconnected or master cylinder has run dry.
Bleed brakes with vacuum bleeding equipment, pressure bleeding
equipment or by manually pumping brake pedal while using bleeder
tubes. Always bleed brake lines in sequence. See BLEEDING SEQUENCE
table.
MASTER CYLINDER BLEEDING
Bench Bleeding
1) Master cylinder must be bled before installation to
prevent excessive amounts of air from entering the brake system,
creating poor brake operation.
2) Place master cylinder in soft-jawed vise. DO NOT tighten
vise enough to damage master cylinder. Install bleeder tubes in both
outlets of master cylinder. See Fig. 5.
Page 326 of 1378
Before bleeding system, exhaust all vacuum from power unit by
depressing brake pedal several times. Bleed master cylinder (if
equipped) with bleeder screws. Bleed slave cylinder on vehicles
equipped with remote mount power assist units. Bleed wheel cylinders
and calipers in sequence. See BLEEDING SEQUENCE table.
BLEEDING SEQUENCE TABLE
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Application Sequence
All Models ................................ RR, LR, RF, LF
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REMOVAL & INSTALLATION
DISC BRAKE CALIPER
Removal & Installation
Caliper removal and installation procedures are same as for
disc pad replacement. To remove caliper from vehicle, disconnect brake
line at caliper and cap hole to prevent contamination.
DISC BRAKE PADS
Removal
1) Drain 2/3 of brake fluid from master cylinder reservoir.
Raise vehicle and support with safety stands. Remove front wheel
assembly.
2) Place "C" clamp on caliper. Solid end of clamp should
contact back of caliper. Screw end should contact metal part of
outboard shoes.
3) Tighten "C" clamp until caliper forces piston to bottom of
bore. Remove both Allen head mounting bolts and lift caliper off
rotor. Support caliper out of the way.
4) On Grand Wagoneer, remove both brake pads from caliper.
Note spring position and support spring from inboard shoe. Remove
sleeves and bushings from caliper.
5) On all other models, hold anti-rattle clip against caliper
adapter and remove outer brake pad. Remove inner brake pad and anti-
rattle clip from caliper adapter.
Installation
1) To install, reverse removal procedure. On Grand Wagoneer,
lubricate new bushings, sleeves, bushing grooves, and small ends of
mounting bolts with silicone lubricant. Install rubber bushings in
caliper mounting ears.
2) On all other models, clean caliper mating surfaces on
adapter with a wire brush. Apply double sided adhesive tape to back
side of inner pad. Clean caliper piston surface. Lubricate caliper
mating surfaces on caliper adapter.
3) On all models, lubricate caliper mounting bolts using
brake corrosion lubricant and tighten mounting bolts. Add brake fluid
to reservoir. Apply brakes until brake pedal is firm. Check brake
fluid level.
DISC BRAKE ROTOR - WRANGLER
Removal
Raise and support vehicle. Remove front wheel and caliper.
Suspend caliper from frame or suspension. Remove rotor from hub.
Installation
Page 327 of 1378
Clean hub and rotor mating surfaces. To install, reverse
removal procedure.
NOTE: DO NOT disconnect brake hose from caliper unless caliper is
to be disassembled.
DISC BRAKE ROTOR - CHEROKEE, COMANCHE & WAGONEER
Removal
1) Raise and support vehicle. Remove front wheel and caliper.
Suspend caliper from frame or suspension. Remove cap, cotter pin, nut
retainer, adjusting nut and thrust washer from spindle.
2) Remove outer bearing from hub. Remove hub and rotor from
spindle. Remove hub and rotor seal. Remove inner bearing from hub.
Installation
1) Apply small amount of "EP" type waterproof wheel bearing
grease in hub cavity. Lubricate inner and outer bearings. Install
inner bearing and seal in rotor. Clean rotor surface (if necessary).
2) Install hub and rotor on spindle. Install outer bearing,
thrust washer and spindle nut. Tighten spindle nut to 17-25 ft. lbs.
(23-34 N.m) while rotating rotor to seat bearings. Loosen spindle nut
1/2 a turn and retighten an additional 19 INCH lbs (2 N.m). Reverse
removal procedure to complete installation.
DISC BRAKE ROTOR - GRAND WAGONEER
Removal
1) Raise vehicle and support with safety stands. Remove wheel
and caliper. On models without front hubs, remove rotor hub cap, drive
gear snap ring, drive gear, pressure spring and spring cup.
2) On models with front hubs, remove screws attaching hub
body to hub clutch and remove hub body from clutch. Remove large and
small retaining rings. Remove hub clutch from axle shaft.
3) On all models, remove wheel bearing outer and inner lock
nuts and retaining ring using Socket (J-6893-D). Remove rotor. Remove
wheel bearings from rotor.
Installation
1) Lubricate bearings with "EP" type waterproof wheel bearing
grease. Install bearings and seal in rotor. Install rotor and inner
lock nut. Inner lock nut has a locating peg on one side. When
installed, peg must face away from bearing.
2) Install wheel, but do not tighten lug nuts completely.
Tighten inner lock nut to 50 ft. lbs. (68 N.m) while rotating wheel.
Back of inner lock nut 1/6 turn (45-65 degrees).
3) Install retaining washer. Ensure that inner lock nut
locating peg is engaged with retaining washer. Install outer lock nut
and tighten to 50 ft. lbs. (68 N.m).
4) On models without front hubs, install pressure spring cup,
pressure spring, drive gear and snap ring. Coat rim of chrome hub
cover with Permatex No. 3 and install cap in rotor hub.
NOTE: Recessed side of spring cup faces outer bearing and flat
side faces pressure spring.
5) On models with front hubs, install hub clutch on axle.
Install large and small hub retaining rings. Install hub body on
clutch and tighten to 30 INCH lbs. (3 N.m). Reverse removal procedure
to complete installation.
DRUM BRAKE SHOES - EXCEPT GRAND WAGONEER
Page 370 of 1378
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DRIV E A XLE - F U LL F LO ATIN G
1988 J e ep C hero ke e
Drive Axles - Dana Full-Floating Axles
Jeep Front & Rear Drive Axles
DESCRIPTION
The axle assembly is an integral carrier type with hypoid
gear ring and pinion. Stamped steel cover is removable for inspection
and repair of differential. Vehicle loads are carried by axle
housings. Axle shafts of "full-floating" rear assemblies may be
removed without disturbing wheel bearings.
Drive pinion depth, pinion bearing preload and differential
side bearing preload are all set by shims.
See LOCKING HUB and 4WD STEERING KNUCKLE articles in this
section for removal and installation procedures for these front drive
axle component parts.
AXLE RATIO & IDENTIFICATION
A metal tag on axle is stamped with gear ratio, part numbers
and limited slip identification. To determine drive axle ratio, refer
to MODEL IDENTIFICATION BY RING GEAR SIZE table.
MODEL IDENTIFICATION BY RING GEAR SIZE
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Model Ring Gear Diameter
44 ....................................... 8.50"
60 ....................................... 9.75"
61 ....................................... 9.75"
70 ...................................... 10.50"
80 ...................................... 11.25"
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FRONT HUB, BEARING, SPINDLE & AXLE SHAFT R & I
FRONT HUB BEARING ADJUSTING SPECIFICATIONS \
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Application ( 1) Ft. Lbs. (N.m)
Adjusting Nut
Step 1 ............................... 50 (68)
Step 2 .......................... Back Off 20
Lock Nut ............................... 50 (68)
( 1) - While Rotating Hub.
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REMOVAL (CHEROKEE, COMANCHE & WAGONEER)
1) Raise and support vehicle. Remove tire and wheel assembly.
Remove disc brake caliper and support out of way.
2) Match mark disc rotor and hub and remove disc rotor.
Remove cotter pin, nut lock and axle hub nut. Remove hub-to-knuckle
bolts. Pull hub assembly off axle shaft. Pull axle shaft through
knuckle to remove. Inspect axle shaft "U" joint and shaft splines for
wear. Replace as necessary.
3) Press hub out of bearings. Remove seals and bearings.