brake fluid 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 90 of 1378
![JEEP CHEROKEE 1988 Service Repair Manual AB BREVIA TIO NS
1988 J e ep C hero ke e
GENERAL INFORMATION
COMMONLY USED ABBREVIATION
"A" ABBREVIATION TABLE
"A" ABBREVIATION TABLE \](/img/16/57037/w960_57037-89.png "JEEP CHEROKEE 1988 Service Repair Manual AB BREVIA TIO NS
1988 J e ep C hero ke e
GENERAL INFORMATION
COMMONLY USED ABBREVIATION
\"A\" ABBREVIATION TABLE
\"A\" ABBREVIATION TABLE \")
AB BREVIA TIO NS
1988 J e ep C hero ke e
GENERAL INFORMATION
COMMONLY USED ABBREVIATION
"A" ABBREVIATION TABLE
"A" ABBREVIATION TABLE \
\
\
\
\
\
\
ABBREVIATION DEFINITION
\
\b\
\
\
\
\
\
A Amperes
A/C Air Conditioning
A/T Automatic Transmission/Transaxle
AAP Auxiliary Accelerator Pump
AB Air Bleed
ABCV Air Bleed Control Valve
ABDC After Bottom Dead Center
ABRS Air Bag Restraint System
ABS Anti-Lock Brake System
AC Alternating Current
ACC A/C Clutch Compressor
ACCS A/C Cycling Switch
ACCUM Accumulator
ACCY Accessory
ACT Air Charge Temperature Sensor
ACV Thermactor Air Control Valve
ADJ Adjust or Adjustable
ADV Advance
AFS Airflow Sensor
AI Air Injection
AIR or A.I.R. Air Injection Reactor
AIS Air Injection System
ALCL Assembly Line Communications Link
ALDL Assembly Line Diagnostic Link
ARC Automatic Ride Control
ASCD Automatic Speed Control Device
ASCS Air Suction Control Solenoid
ASD Auto Shutdown
ASDM Air Bag System Diagnostic Module
ASV Air Suction Valve
ATC Automatic Temperature Control
ATDC After Top Dead Center
ATF Automatic Transmission Fluid
ATS Air Temperature Sensor
AXOD Automatic Transaxle Overdrive
Abs. Absolute
Accy. Accessory
Alt. Alternator or Altitude
Amp. Ampere
Assy. Assembly
Auto. Automatic
Aux. Auxiliary
Avg. Average
\
\
\
\
\
\
\
\f
"B" ABBREVIATION TABLE
"B" ABBREVIATION TABLE
Page 192 of 1378
\003
AN TI- L O CK B RAK E S A FE TY P R EC AU TIO NS
1988 J e ep C hero ke e
GENERAL INFORMATION
Anti-Lock Brake Safety Precautions
* PLEASE READ THIS FIRST *
This article is intended for general information purposes
only. This information may not apply to all makes and models. If
vehicle is equipped with Anti-Lock Brake System (ABS), refer to
appropriate ANTI-LOCK BRAKE SYSTEM article in the BRAKES section for
description, operation, depressurizing, testing, system bleeding,
trouble shooting and servicing of specific system.
WARNING: Failure to depressurize ABS could lead to physical injury.
ANTI-LOCK BRAKE SAFETY PRECAUTIONS
WARNING: Failure to depressurize ABS could lead to physical injury.
* NEVER open a bleeder valve or loosen a hydraulic line
while ABS is pressurized.
* NEVER disconnect or reconnect any electrical connectors
while ignition is on. Damage to ABS control unit may result.
* DO NOT attempt to bleed hyudarulic system without first
referring to the appropriate ANTI-LOCK BRAKE SYSTEM article
in the BRAKES section.
* Only use specially designed brake hoses/lines on ABS equipped
vehicles.
* DO NOT tap on speed sensor components (sensor, sensor rings).
Sensor rings must be pressed into hubs, NOT hammered into
hubs. Striking these components can cause demagnetization or
a loss of polarization, affecting the accuracy of the speed
signal returning to the ABS control unit.
* DO NOT mix tire sizes. Increasing the width, as long as tires
remain close to the original diameter, is acceptable. Rolling
diameter must be identical for all 4 tires. Some
manufacturers recommend tires of the same brand, style and
type. Failure to follow this precaution may cause inaccurate
wheel speed readings.
* DO NOT contaminate speed sensor components with grease. Only
use recommended coating, when system calls for an
anti-corrosion coating.
* When speed sensor components have been removed, ALWAYS check
sensor-to-ring air gaps when applicable. These specifications
can be found in each appropriate article.
* ONLY use rocommended brake fluids. DO NOT use silicone brake
fluids in an ABS equipped vehicle.
* When instlling transmittion devices (CB's, telephones, etc.)
on ABS equipped vehicles, DO NOT locate the antenna near the
ABS control unit (or any control unit).
* Disconnect all on-board computers, when using electric
welding equipment.
* DO NOT expose the ABS control unit to prolonged periods of
high heat (185
F/85 C for 2 hours is generally considered a
maximum limit).
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 277 of 1378
BRAK E S YSTE M B LE ED IN G
1988 J e ep C hero ke e
1988 BRAKES
Jeep - Brake System Bleeding
Cherokee, Comanche, Grand Wagoneer, Wagoneer, Wrangler
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. 1.
Fig. 1: Bleeding Master Cylinder
Courtesy of American Motors/Jeep Corp.
3) Fill master cylinder with clean brake fluid that meets DOT
3 specifications. Ensure that the end of bleeder tubes are submerged
Page 278 of 1378
in the brake fluid.
4) Using proper sized rod, apply and release master cylinder
until no air bubbles exist in brake fluid flow. Once all air bubbles
are gone from master cylinder secure cap and install.
5) Bleeder tubes should be left installed on master cylinder
until master cylinder in installed. Master cylinder must be bled at
brake lines and wheels after installation.
Bleeding On Vehicle
1) Install master cylinder on vehicle after bench bleeding.
Remove bleeder lines and install brake lines. DO NOT fully tighten
brake lines at this time.
2) Slowly force brake pedal to the floor and hold in this
position. Tighten brake lines and release brake pedal. Repeat
procedure until no air bubbles exist at brake lines. Remaining wheel
cylinder or calipers may be require bleeding.
HYDRAULIC CONTROL VALVES
Hold Off Valve
1) Prior to the pressure tank bleeding procedure, the hold
off valve incorporated in the combination valve must be correctly
positioned. This allows brake fluid to flow through the combination
valve to the entire brake system.
2) The valve stem of the hold off valve may be retained using
tools available from Chrysler Motors (C-4121) or General Motors
(J-23709) during bleeding procedure. See Figs. 2 and 3. Remove valve
retainer once brake bleeding procedure is complete.
CAUTION: DO NOT use rigid clamp to position valve stem. Damage to
the valve assembly may result causing brake failure.
Fig. 2: Positioning Hold Off Valve
Courtesy of American Motors/Jeep Corp.
Page 279 of 1378
Fig. 3: Positioning Hold Off Valve
Courtesy of American Motors/Jeep Corp.
VACUUM BLEEDING
Fill master cylinder. Install vacuum bleed equipment to first
bleeder valve to be serviced. Open bleeder valve 3/4-1 turn. Depress
vacuum pump and pull fluid into reservoir jar. Bleed each bleeder
valve in sequence. See BLEEDING SEQUENCE table.
PRESSURE BLEEDING
1) Clean master cylinder cap and surrounding area. Remove
cap. With pressure tank at least 1/2 full, connect to master cylinder
with adapters. Attach bleeder hose to first bleeder valve to be
serviced. See BLEEDING SEQUENCE table.
2) Place other end of hose in clean glass jar partially
filled with clean brake fluid so end of hose is submerged in fluid.
The hold off valve must be positioned properly before pressure
bleeding (if equipped). See HYDRAULIC CONTROL VALVES under BRAKE
SYSTEM BLEEDING in this article.
3) Open release valve on pressure bleeder. Follow equipment
manufacturer's pressure instructions or see PRESSURE BLEEDER SETTINGS
table. Open bleeder screw 3/4-1 turn and note fluid flow.
4) Close bleeder screw when fluid flowing is free of bubbles.
Repeat procedure on remaining wheels in proper sequence. Check brake
pedal operation after bleeding has been completed.
5) Remove pressure bleeding equipment and valve retainer from
hold off valve. Ensure that master cylinder is full of fluid.
PRESSURE BLEEDER SETTINGS TABLE
\
\
\
\
\
\
Application psi (kg/cm)
Page 280 of 1378
![JEEP CHEROKEE 1988 Service Repair Manual All Models ............................... 15-20 (1.1-1.4) \
\
\
\
\
\](/img/16/57037/w960_57037-279.png "JEEP CHEROKEE 1988 Service Repair Manual All Models ............................... 15-20 (1.1-1.4) \
\
\
\
\
\")
All Models ............................... 15-20 (1.1-1.4) \
\
\
\
\
\
MANUAL BLEEDING
NOTE: When bleeding disc brakes, air may tend to cling to caliper
walls. Lightly tap caliper, while bleeding, to aid in
removal of air.
1) Fill master cylinder. Install bleeder hose to first
bleeder valve to be serviced. See BLEEDING SEQUENCE table. Submerge
other end of hose in clean glass jar partially filled with clean brake
fluid. See Fig. 4.
2) Open bleeder valve 3/4-1 turn. Depress brake pedal slowly
through full travel. Close bleeder valve and release pedal. Repeat
procedure until flow of fluid shows no signs of air bubbles.
NOTE: When bleeding brake system manually, ensure bleeder valve is
closed when brake pedal is released.
Fig. 4: Wheel Cylinder Bleeding Procedure
Courtesy of American Motors/Jeep Corp.
BLEEDING SEQUENCE
Page 282 of 1378
\003
* 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 287 of 1378
NOTE: Electro-magnetic interference (EMI) may be caused by
incorrect installation of accessories or components. EMI can
result in improper system operation.
BACKING PLATES
BACKING PLATE INSPECTION \
\
\
\
\
\
\
Condition Code Procedure
Anchor pin bent ......... B .. Require repair or replacement.
Anchor pin broken ....... A ............ Require replacement.
Anchor pin worn, affecting
structural integrity ... B ............ Require replacement.
Backing plate bent ...... B .. Require repair or replacement.
Backing plate broken .... A ............ Require replacement.
Backing plate cracked ... B .. Require repair or replacement.
Corroded, affecting
structural integrity .... A ............ Require replacement.
Loose ................... B .. Require repair or replacement.
Missing ................. C ............ Require replacement.
Shoe lands worn ......... A .. Require repair or replacement.
\
\
\
\
\
\
\
BRAKE FLUID
CAUTION: Most manufacturers prohibit the use of DOT 5 brake fluid
in a system equipped with ABS.
DOT 3, DOT 4, and DOT 5.1 brake fluids are clear or light
amber in color. DOT 5 brake fluid is violet in color. Correct fluid
required for the brake system is stamped on the master cylinder cover.
BRAKE FLUID INSPECTION
\
\
\
\
\
\
\
Condition Code Procedure
Beyond service interval . 3 .. Suggest flushing and refilling
with correct fluid.
Brake fluid type
incorrect .............. B .. Require flushing and refilling
with correct fluid.
Contaminated, for example,
fluid other than brake
fluid present .......... A or B ....... ( 1) Require service.
Hydraulic component ..... 3 .. Suggest flushing and refilling
overhaul or replacement with correct fluid.
Rubber master cylinder
cover gasket distorted
and gummy .............. A .......... ( 2) Require replacement
of gasket.
( 1) - If a fluid other than brake fluid is present in the brake
system which DOES affect the rubber parts, the required
service is to:
* Remove all components having rubber parts from the
system.
* Flush lines with denatured alcohol or brake cleaner
* Repair or replace all components having rubber parts
* Flush and fill with correct brake fluid. (Code A)
If a fluid other than brake fluid is present in the brake
Page 288 of 1378
system which DOES NOT affect the rubber parts, the required
service is to flush and fill with the correct brake fluid.
(Code B)
( 2) - This condition may indicate contaminated brake fluid.
\
\
\
\
\
\
\
BRAKE FRICTION MATERIAL
See FRICTION MATERIAL .
BRAKE PADS
See FRICTION MATERIAL .
BRAKE PEDALS
BRAKE PEDAL INSPECTION \
\
\
\
\
\
\
Condition Code Procedure
Bent, affecting
performance ............ A .. Require repair or replacement.
Broken .................. A .. Require repair or replacement.
Pedal pad missing ....... C .... Require replacement of pedal
pad.
Pedal pad worn .......... 1 ............ Suggest replacement.
Pivot bushings worn,
affecting performance .. A .... Require replacement of pivot
bushings.
\
\
\
\
\
\
\
BRAKE SHOES
See FRICTION MATERIAL .
BRAKE SHOE HARDWARE
See also SELF-ADJUSTING SYSTEMS .
BRAKE SHOE HARDWARE INSPECTION
\
\
\
\
\
\
\
Condition Code Procedure
Broken .................. A ............ Require replacement.
Distorted ............... A ............ Require replacement.
Missing ................. C ............ Require replacement.
Surfaces rust-pitted .... 1 ............ Suggest replacement.
Worn, affecting
performance ............ A ............ Require replacement.
\
\
\
\
\
\
\
BRAKE STOPLIGHT SWITCHES
BRAKE STOPLIGHT INSPECTION \
\
\
\
\
\
\
Condition Code Procedure
Bent .................... B ............ Require replacement.
Broken .................. A ............ Require replacement.
Connector broken ........ A .. Require repair or replacement.
Connector (Weatherpack
type) leaking .......... A .. Require repair or replacement.