electrical JEEP LIBERTY 2002 KJ / 1.G Workshop Manual

JUMP STARTING
STANDARD PROCEDURE - JUMP STARTING
PROCEDURE
WARNING: REVIEW ALL SAFETY PRECAUTIONS
AND WARNINGS IN GROUP 8A, BATTERY/START-
ING/CHARGING SYSTEMS DIAGNOSTICS.
²DO NOT JUMP START A FROZEN BATTERY,
PERSONAL INJURY CAN RESULT.
²DO NOT JUMP START WHEN BATTERY INDI-
CATOR DOT IS YELLOW OR BRIGHT COLOR. BAT-
TERY CAN EXPLODE.
²DO NOT ALLOW JUMPER CABLE CLAMPS TO
TOUCH EACH OTHER WHEN CONNECTED TO A
BOOSTER SOURCE.
²DO NOT USE OPEN FLAME NEAR BATTERY.
²REMOVE METALLIC JEWELRY WORN ON
HANDS OR WRISTS TO AVOID INJURY BY ACCI-
DENTAL ARCHING OF BATTERY CURRENT.
²WHEN USING A HIGH OUTPUT BOOSTING
DEVICE, DO NOT ALLOW DISABLED VEHICLE'S
BATTERY TO EXCEED 16 VOLTS. PERSONAL
INJURY OR DAMAGE TO ELECTRICAL SYSTEM
CAN RESULT.
CAUTION: When using another vehicle as a
booster, do not allow vehicles to touch. Electrical
systems can be damaged on either vehicle.
TO JUMP START A DISABLED VEHICLE:
(1) Raise hood on disabled vehicle and visually
inspect engine compartment for:
²Generator drive belt condition and tension.
²Fuel fumes or leakage, correct if necessary.
²Frozen battery.
²Yellow or bright color test indicator, if equipped.
²Low battery fluid level.
CAUTION: If the cause of starting problem on dis-
abled vehicle is severe, damage to booster vehicle
charging system can result.
(2) When using another vehicle as a booster
source, turn off all accessories, place gear selector in
park or neutral, set park brake or equivalent and
operate engine at 1200 rpm.
(3) On disabled vehicle, place gear selector in park
or neutral and set park brake or equivalent. Turn
OFF all accessories.
(4) Connect jumper cables to booster battery. RED
clamp to positive terminal (+). BLACK clamp to neg-
ative terminal (-). DO NOT allow clamps at opposite
end of cables to touch, electrical arc will result (Fig.
5). Review all warnings in this procedure.(5) On disabled vehicle, connect RED jumper cable
clamp to battery positive (+) terminal. Connect
BLACK jumper cable clamp to the engine as close to
the ground cable connection as possible (Fig. 5).
CAUTION: Do not crank starter motor on disabled
vehicle for more than 15 seconds, starter will over-
heat and could fail.
(6) Allow battery in disabled vehicle to charge to
at least 12.4 volts (75% charge) before attempting to
start engine. If engine does not start within 15 sec-
onds, stop cranking engine and allow starter to cool
(15 min.), before cranking again.
DISCONNECT CABLE CLAMPS AS FOLLOWS:
²Disconnect BLACK cable clamp from engine
ground on disabled vehicle.
²When using a Booster vehicle, disconnect
BLACK cable clamp from battery negative terminal.
Disconnect RED cable clamp from battery positive
terminal.
²Disconnect RED cable clamp from battery posi-
tive terminal on disabled vehicle.
TOWING
STANDARD PROCEDURE - TOWING
A vehicle equipped with SAE approved wheel lift-
type towing equipment can be used to tow Jeep vehi-
cles. When towing a 4WD vehicle using a wheel-lift
Fig. 5 Jumper Cable Clamp Connections
1 - BOOSTER BATTERY
2 - NEGATIVE JUMPER CABLE
3 - ENGINE GROUND
4 - DO NOT ALLOW VEHICLES TO TOUCH
5 - BATTERY NEGATIVE CABLE
6 - DISCHARGED BATTERY
7 - POSITIVE JUMPER CABLE
0 - 6 LUBRICATION & MAINTENANCEKJ

BUSHINGS
REMOVAL - STABILIZER BAR BUSHINGS
(1) Raise vehicle on hoist.
(2) Remove the stabilizer bushing clamps.
(3) Remove the stabilizer bushings from the stabi-
lizer bar.
INSTALLATION - STABILIZER BAR BUSHINGS
(1) Install the stabilizer bushings to the stabilizer
bar.
(2) Install the stabilizer bushing clamps. Tighten
the nuts to 149 N´m (110 ft.lbs.).
(3) Lower the vehicle.
HUB / BEARING
REMOVAL
(1) Raise and support the vehicle.
(2) Remove the tire and wheel assembly.
(3) Remove the caliper adapter (Refer to 5 -
BRAKES/HYDRAULIC/MECHANICAL/DISC
BRAKE CALIPERS - REMOVAL).
CAUTION: Never allow the disc brake caliper to
hang from the brake hose. Damage to the brake
hose will result. Provide a suitable support to hang
the caliper securely.
(4) Remove the disc brake rotor (Refer to 5 -
BRAKES/HYDRAULIC/MECHANICAL/ROTORS -
REMOVAL).
(5) Remove the wheel speed sensor (Refer to 5 -
BRAKES/ELECTRICAL/FRONT WHEEL SPEED
SENSOR - REMOVAL).
(6) Remove the bracket securing the wheel speed
sensor wire.
(7) Remove the axle shaft nut. (if equipped with
four wheel drive)
(8) Remove the three mounting bolts for the hub/
bearing assembly.
(9) Remove the hub/bearing.
INSTALLATION
(1) Install the hub/bearing assembly to the vehicle.
(2) Install the three mounting bolts for the hub/
bearing. Tighten the bolt to 130 N´m (96 ft.lbs.).
(3) Install the axle shaft nut. Tighten the nut to
135 N´m (100 ft.lbs.). (if equipped with four wheel
drive)
(4) Install the bracket to the wheel speed sensor
wire.
(5) Install the wheel speed sensor to the hub.
Tighten the bolt to 13.5 N´m (10 ft.lbs.) (Refer to 5 -BRAKES/ELECTRICAL/FRONT WHEEL SPEED
SENSOR - INSTALLATION).
(6) Install the disc brake rotor (Refer to 5 -
BRAKES/HYDRAULIC/MECHANICAL/ROTORS -
INSTALLATION).
(7) Install the disc brake caliper adapter. Tighten
the nut to 135 N´m (100 ft.lbs.) (Refer to 5 -
BRAKES/HYDRAULIC/MECHANICAL/ROTORS -
INSTALLATION).
(8) Install the tire and wheel assembly. (Refer to
22 - TIRES/WHEELS/WHEELS - STANDARD PRO-
CEDURE).
KNUCKLE
REMOVAL
(1) Raise and support the vehicle.
(2) Remove the tire and wheel assembly.
(3) Remove the caliper adapter. (Refer to 5 -
BRAKES/HYDRAULIC/MECHANICAL/DISC
BRAKE CALIPER ADAPTER - REMOVAL).
CAUTION: Never allow the disc brake caliper to
hang from the brake hose. Damage to the brake
hose will result. Provide a suitable support to hang
the caliper securely.
(4) Remove the disc brake rotor. (Refer to 5 -
BRAKES/HYDRAULIC/MECHANICAL/ROTORS -
REMOVAL).
(5) Remove the wheel speed sensor. (Refer to 5 -
BRAKES/ELECTRICAL/FRONT WHEEL SPEED
SENSOR - REMOVAL).
(6) Remove the axle shaft nut. (if equipped with
four wheel drive)
(7) Remove the hub/bearing. (Refer to 2 - SUS-
PENSION/FRONT/HUB / BEARING - REMOVAL).
(8) Remove the outer tie rod end. (Refer to 19 -
STEERING/LINKAGE/TIE ROD END - REMOVAL).
(9) Remove the lower ball joint nut.
(10) Seperate the lower ball joint from the suspen-
sion arm using tool C±4150A.
(11) Remove the upper ball joint nut.
(12) Seperate the upper ball joint from the knuckle
using tool C±4150A.
(13) Remove the knuckle from the vehicle.
INSTALLATION
(1) Install the knuckle to the vehicle.
(2) Install the upper ball joint nut. Tighten the nut
to 81 N´m (60 ft.lbs.).
(3) Install the lower ball joint nut. Tighten the nut
to 81 N´m (60 ft.lbs.).
(4) Install the outer tie rod end. (Refer to 19 -
STEERING/LINKAGE/TIE ROD END - INSTALLA-
TION).
KJFRONT 2 - 9

(5) Install the hub/bearing. (Refer to 2 - SUSPEN-
SION/FRONT/HUB / BEARING - INSTALLATION).
(6) Install the axle shaft nut. Tighten the nut to
135 N´m (96 ft.lbs.).(if equipped with four wheel
drive).
(7) Install the wheel speed sensor. (Refer to 5 -
BRAKES/ELECTRICAL/FRONT WHEEL SPEED
SENSOR - INSTALLATION).
(8) Install the disc brake rotor. (Refer to 5 -
BRAKES/HYDRAULIC/MECHANICAL/ROTORS -
INSTALLATION).
(9) Install the caliper adapter. (Refer to 5 -
BRAKES/HYDRAULIC/MECHANICAL/DISC
BRAKE CALIPER ADAPTER - INSTALLATION).
(10) Install the tire and wheel assembly. (Refer to
22 - TIRES/WHEELS/WHEELS - STANDARD PRO-
CEDURE).
(11) Perform the set toe procedure (Refer to 2 -
SUSPENSION/WHEEL ALIGNMENT - STANDARD
PROCEDURE).
LOWER BALL JOINT
DIAGNOSIS AND TESTING - LOWER BALL
JOINT
(1) Raise the vehicle on a drive-on hoist.
NOTE: If a drive-on hoist is not available, use
wooden blocks with jack stands to support the
lower control arm in the ball joint area. Place the
jack stands appropriately and lower the hoist plac-
ing weight on the lower control arm. The lower con-
trol arms should now be supporting the vehicle
weight.
(2) With the use of jack stands, lift the front end
off the hoist and position wooden blocks underneath
both lower control arms supporting the vehicles
weight.
(3) Remove the tire and wheel assembly.
(4) Attach a dial indicator to the base of the lower
control arm and align the dial indicator's contact
point with the direction of the stud axis, touch the
machined flat on the knuckle and zero the dial indi-
cator. (Fig. 2)
NOTE: Use care when applying the load to the
knuckle, so the parts are not damaged using care
not to tear the boot.
(5) From the front of the vehicle, insert a pry bar
to get it rested on the lower control arm and use
lever principle to push the knuckle up until the arm
of the dial indicator no longer moves.(6) Record the ball joint movement on each side of
the vehicle. The end play is acceptable with no more
than 1.5mm of end play back to back.LOWER CONTROL ARM
REMOVAL
(1) Raise and support the vehicle.
(2) Remove the tire and wheel assembly.
(3) Remove the lower clevis bracket bolt at the
lower control arm.
(4) Remove the stabilizer link bolt at the lower
control arm.
(5) Remove the lower ball joint nut.
(6) Separate the lower ball joint from the lower
control arm using tool C-4150A.
NOTE: Marking the lower control arm pivot bolts
front and rear will aid in the assembly procedure.
(7) Mark the lower control arm pivot bolts front
and rear.
(8) Remove the front cam/pivot bolt. (Fig. 3)
(9) Remove the rear cam/pivot bolt. (Fig. 3)
(10) Remove the lower control arm from the vehi-
cle.
INSTALLATION
(1) Install the lower control arm to the vehicle.
(2) Install the rear cam/pivot bolt.
(3) Install the front cam/pivot bolt.
(4) Install the lower ball joint nut. Tighten the nut
to 81 N´m (60 ft.lbs.)
Fig. 2 SUSPENSION IN THE CURB POSITION
1-PRYBAR
2 - BALL JOINT
3 - DIAL INDICATOR
4 - WOODEN BLOCK OR SUPPORT
5 - CLAMP
2 - 10 FRONTKJ
KNUCKLE (Continued)

REMOVAL - LEFT SIDE
(1) Raise and support the vehicle.
(2) Remove the left side tire and wheel assembly.
(3) Remove the upper ball joint nut.
(4) Separate the upper ball joint from the steering
knuckle using tool C-4150A.
(5) Lower the vehicle.
(6) Remove the battery (Refer to 8 - ELECTRI-
CAL/BATTERY SYSTEM/BATTERY - REMOVAL).
(7) Unclip the power center and move it to the side
out of the way.
(8) Remove the battery tray (Refer to 8 - ELEC-
TRICAL/BATTERY SYSTEM/TRAY - REMOVAL).
(9) Disconnect the battery temperature sensor
from the battery tray.
(10) Remove the upper control arm rear bolt by
using a ratchet and extension under the steering
shaft and positioned by the power steering reservoir.
(Fig. 10)
(11) Remove the upper control arm front bolt.
(12) Remove the upper control arm from the vehi-
cle.
INSTALLATION
INSTALLATION - RIGHT SIDE
(1) Install the upper control arm to the vehicle.
(2) Install the upper control arm front bolt.
Tighten the bolt to 122 N´m (90 ft.lbs.).
(3) Install the upper control arm rear bolt. Tighten
the bolt to 122 N´m (90 ft.lbs.).
(4) Install the cruise control servo mounting nuts.(5) Install the air box (Refer to 9 - ENGINE/AIR
INTAKE SYSTEM/AIR CLEANER ELEMENT -
INSTALLATION).
(6) Install the upper ball joint nut. Tighten the nut
to 81 N´m (60 ft.lbs.).
(7) Install the right side tire and wheel assembly.
(Refer to 22 - TIRES/WHEELS/WHEELS - STAN-
DARD PROCEDURE).
(8) Lower the vehicle.
(9) Set the toe and center the steering wheel
(Refer to 2 - SUSPENSION/WHEEL ALIGNMENT -
STANDARD PROCEDURE).
INSTALLATION - LEFT SIDE
(1) Install the upper control arm to the vehicle.
(2) Install the upper control arm front bolt (Fig.
11). Tighten the bolt to 122 N´m (90 ft.lbs.).
(3) Install the upper control arm rear bolt (Fig.
11). Tighten the bolt to 122 N´m (90 ft.lbs.).
(4) Reconnect the battery temperature sensor to
the battery tray.
(5) Install the battery tray (Refer to 8 - ELECTRI-
CAL/BATTERY SYSTEM/TRAY - INSTALLATION).
(6) Install the battery (Refer to 8 - ELECTRICAL/
BATTERY SYSTEM/BATTERY - INSTALLATION).
(7) Reclip and mount the power center.
(8) Install the upper ball joint nut (Fig. 11).
Tighten the nut to 81 N´m (60 ft.lbs.).
(9) Install the left side tire and wheel assembly.
(Refer to 22 - TIRES/WHEELS/WHEELS - STAN-
DARD PROCEDURE).
(10) Lower the vehicle.
(11) Set the toe and center the steering wheel
(Refer to 2 - SUSPENSION/WHEEL ALIGNMENT -
STANDARD PROCEDURE).
Fig. 10 REAR BOLT
1 - STEERING SHAFT
2 - REAR BOLT
3 - RATCHET WITH AN EXTENSION
Fig. 11 UPPER CONTROL ARM
KJFRONT 2 - 15
UPPER CONTROL ARM (Continued)

JUNCTION BLOCK
DESCRIPTION
The junction block and a rear brake proportioning
valve. The valve is not repairable and must be
replaced as an assembly if diagnosis indicates this is
necessary.
OPERATION
PROPORTIONING VALVE
The proportioning valve is used to balance front-
rear brake action at high decelerations. The valve
allows normal fluid flow during moderate braking.
The valve only controls fluid flow during high decel-
erations brake stops. If the primary brake hydraulic
circuit cannot build pressure a by-pass feature is
activated allowing full flow and pressure to the rear
brakes.
DIAGNOSIS AND TESTING - PROPORTIONING
VALVE
The valve controls fluid flow. If fluid enters the
valve and does not exit the valve the combination
valve must be replaced.
REMOVAL
(1) Install prop rod on the brake pedal to keep
pressure on the brake system.
(2) Remove the brake lines from the junction
block.
(3) Remove mounting nuts and bolt and remove
the junction block (Fig. 31).
INSTALLATION
(1) Install the junction block on the mounting
studs.
(2) Install mounting nuts and bolt. Tighten to 14
N´m (125 in. lbs.).
(3) Install brake lines to the junction block and
tighten to 20 N´m (180 in. lbs.).
(4) Bleed ABS brake system (Refer to 5 - BRAKES
- STANDARD PROCEDURE).
PEDAL
DESCRIPTION
A suspended-type brake pedal is used, the pedal
pivots on a shaft mounted in the steering coloumn
support bracket. The bracket is attached to the dash
panel. The unit is serviced as an assembly, except for
the pedal pad.
OPERATION
The brake pedal is attached to the booster push
rod. When the pedal is depressed, the primary
booster push rod is depressed which move the booster
secondary rod. The booster secondary rod depress the
master cylinder piston.
REMOVAL
(1) Remove the knee blocker under the steering
column,(Refer to 23 - BODY/INSTRUMENT PANEL/
KNEE BLOCKER - REMOVAL).
(2) Remove the retainer clip securing the booster
push rod to pedal (Fig. 32).
(3) Remove the brake lamp switch,(Refer to 8 -
ELECTRICAL/LAMPS/LIGHTING - EXTERIOR/
BRAKE LAMP SWITCH - REMOVAL).
(4) Remove the nuts securing the pedal to the col-
umn bracket.
(5) Remove the pedal from the vehicle.
INSTALLATION
(1) Install the pedal into the vehicle.
(2) Install the nuts securing the pedal to the col-
umn bracket.
(3) Tighten the nuts to 22.6 N´m (200 in. lbs.).
(4) Lubricate the brake pedal pin and bushings
with Mopar multi-mileage grease.
(5) Install the booster push rod on the pedal pin
and install a new retainer clip (Fig. 32).
(6) Install the brake lamp switch,(Refer to 8 -
ELECTRICAL/LAMPS/LIGHTING - EXTERIOR/
BRAKE LAMP SWITCH - INSTALLATION).
(7) Install the knee blocker,(Refer to 23 - BODY/
INSTRUMENT PANEL/KNEE BLOCKER - INSTAL-
LATION).
Fig. 31 JUNCTION BLOCK
1 - JUNCTION BLOCK
2 - MOUNTING NUT
5 - 20 BRAKES - BASEKJ

(2) Attach bleed tubes to cylinder outlet ports.
Then position each tube end into reservoir (Fig. 40).
(3) Fill reservoir with fresh brake fluid.
(4) Press cylinder pistons inward with wood dowel.
Then release pistons and allow them to return underspring pressure. Continue bleeding operations until
air bubbles are no longer visible in fluid.
REMOVAL
(1) Siphon and drain the fluid from the reservoir.
(2) Remove the brake lines at the master cylinder.
(3) Disconnect the fluid level electrical connector
from the reservoir.
(4) Remove mounting nuts from the master cylin-
der.
(5) Remove master cylinder.
(6) Remove cylinder cover and drain the rest of the
fluid.
(7) If master cylinder reservoir requires service-
,(Refer to 5 - BRAKES/HYDRAULIC/MECHANICAL/
FLUID RESERVOIR - REMOVAL). (Fig. 41)
INSTALLATION
NOTE: If master cylinder is replaced, bleed cylinder
before installation.
(1) Clean cylinder mounting surface of brake
booster.
(2) Install master cylinder onto brake booster
studs.
(3) Install mounting nuts and tighten to 25 N´m
(220 in. lbs.).
(4) Connect the brake lines to the master cylinder
and tighten to 20 N´m (180 in. lbs.).
(5) Connect fluid level electrical connector to the
reservoir.
(6) Fill and bleed base brake system,(Refer to 5 -
BRAKES - STANDARD PROCEDURE).
Fig. 38 Typical Booster Vacuum Test Connections
1 - TEE FITTING
2 - SHORT CONNECTING HOSE
3 - CHECK VALVE
4 - CHECK VALVE HOSE
5 - CLAMP TOOL
6 - INTAKE MANIFOLD
7 - VACUUM GAUGE
Fig. 39 TYPICAL - VACUUM CHECK VALVE AND
SEAL
1 - BOOSTER CHECK VALVE
2 - APPLY TEST VACUUM HERE
3 - VALVE SEAL
Fig. 40 MASTER - TYPICAL
1 - BLEEDING TUBES
2 - RESERVOIR
KJBRAKES - BASE 5 - 25
MASTER CYLINDER (Continued)

FLUID RESERVOIR
REMOVAL
(1) Install prop rod on brake pedal to keep pres-
sure on the brake system.
(2) Remove reservoir cap and siphon fluid into
drain container.
(3) Remove the electrical connector from the fluid
level switch in the reservoir.
(4) Remove the reservoir mounting bolt.
(5) Remove the reservoir from the master cylinder
by pulling upwards.
(6) Remove old grommets from cylinder body.
INSTALLATION
(1) Fill and bleed master cylinder on bench before
installation in vehicle.
CAUTION: Do not use any type of tool to install the
grommets. Tools may cut, or tear the grommets cre-
ating a leak problem after installation. Install the
grommets using finger pressure only.
(2) Lubricate new grommets with clean brake fluid
and Install new grommets in cylinder body. Use fin-
ger pressure to install and seat grommets.
(3) Start reservoir in grommets. Then rock reser-
voir back and forth while pressing downward to seat
it in grommets.
(4) Install the mounting bolt for the reservoir to
the master cylinder.
(5) Reconnect the electrical connector to the fluid
reservoir level switch.(6) Remove the prop rod from the vehicle.
(7) Fill and bleed base brake system,(Refer to 5 -
BRAKES - STANDARD PROCEDURE).
FLUID
DIAGNOSIS AND TESTING - BRAKE FLUID
CONTAMINATION
Indications of fluid contamination are swollen or
deteriorated rubber parts.
Swollen rubber parts indicate the presence of
petroleum in the brake fluid.
To test for contamination, put a small amount of
drained brake fluid in clear glass jar. If fluid sepa-
rates into layers, there is mineral oil or other fluid
contamination of the brake fluid.
If brake fluid is contaminated, drain and thor-
oughly flush system. Replace master cylinder, propor-
tioning valve, caliper seals, wheel cylinder seals,
Antilock Brakes hydraulic unit and all hydraulic
fluid hoses.
STANDARD PROCEDURES - MASTER
CYLINDER FLUID LEVEL
Always clean the master cylinder reservoir and cap
before adding fluid. This will prevent dirt from fall-
ing in the reservoir and contaminating the brake
fluid.
The reservoir has a ADD and a FULL mark on the
side (Fig. 42) fill to the FULL mark.
Fig. 41 MASTER CYLINDER
1 - FLUID RESERVOIR
2 - BOOSTER
3 - FLUID LEVEL SWITCH
4 - MASTER CYLINDER
5 - FLUID LEVEL MARKS
Fig. 42 TYPICAL - MASTER CYLINDER FLUID
LEVEL
1 - FLUID LEVEL MARKS
2 - RESERVOIR
5 - 26 BRAKES - BASEKJ
MASTER CYLINDER (Continued)

(3) Push the cables thru the floor and seat the
grommets.
(4) Reconnect the two cables to the front mount.
(5) Install the cable saddle bracket (Fig. 47).
(6) Lay the carpet back down in the rear.
(7) Install the rear seat (Refer to 23 - BODY/
SEATS/SEAT - INSTALLATION).
(8) Remove the lock out device on the lever.
(9) Test the parking brake.
LEVER
REMOVAL
The center floor console must be removed to service
the parking brake lever,(Refer to 23 - BODY/INTERI-
OR/FLOOR CONSOLE - REMOVAL) .
(1) Lock out the parking brakes (Refer to 5 -
BRAKES/PARKING BRAKE - ADJUSTMENTS).
(2) Disengage the front cables from the equalizer
(Fig. 49).
(3) Disconnect the parking brake lamp switch wire
(Fig. 49).
(4) Remove the parking brake lever assembly
mounting bolts (Fig. 50).
(5) Remove the lever assembly.
INSTALLATION
(1) Install the parking brake lever assembly.
(2) Install the parking brake lever assembly to the
mounting bolts. Tighten (Fig. 50).
Install the center floor console, (Refer to 23 -
BODY/INTERIOR/FLOOR CONSOLE - INSTALLA-
TION).
(3) Engage the front cables to the equalizer (Fig.
49).(4) Reconnect the parking brake lamp switch wire
(Fig. 49).
(5) If installing a new parking brake lever remove
the pin that come on the lever when shipped.
(6) If you are reinstalling the original park brake
lever remove the lock out device at this time.
(7) Test the parking brake lever. (Fig. 50).
Fig. 48 CABLE FRONT MOUNT
1 - RETAINER CLIPS
2 - CABLES
Fig. 49 PARKING BRAKE LEVER
1 - PARK BRAKE LEVER ASSEMBLY
2 - EQUALIZER
Fig. 50 LEVER MOUNT
1 - ELECTRICAL CONNECTOR
2 - PARK BRAKE LEVER ASSEMBLY
3 - CABLE
KJBRAKES - BASE 5 - 31
CABLES (Continued)

BRAKES - ABS
TABLE OF CONTENTS
page page
BRAKES - ABS
DESCRIPTION.........................32
OPERATION...........................32
DIAGNOSIS AND TESTING - ANTILOCK
BRAKING SYSTEM....................33
STANDARD PROCEDURE - ABS BRAKE
BLEEDING...........................33
SPECIFICATIONS.......................33
ELECTRICAL
DESCRIPTION.........................34
OPERATION...........................34FRONT WHEEL SPEED SENSOR
REMOVAL.............................34
INSTALLATION.........................34
REAR WHEEL SPEED SENSOR
REMOVAL.............................35
INSTALLATION.........................35
HCU (HYDRAULIC CONTROL UNIT)
DESCRIPTION.........................35
OPERATION...........................35
REMOVAL.............................36
INSTALLATION.........................36
BRAKES - ABS
DESCRIPTION
ANTILOCK BRAKING SYSTEM
The purpose of the antilock system is to prevent
wheel lockup during periods of high wheel slip. Pre-
venting lockup helps maintain vehicle braking action
and steering control.
The antilock CAB activates the system whenever
sensor signals indicate periods of high wheel slip.
High wheel slip can be described as the point where
wheel rotation begins approaching 20 to 30 percent of
actual vehicle speed during braking. Periods of high
wheel slip occur when brake stops involve high pedal
pressure and rate of vehicle deceleration.
Battery voltage is supplied to the CAB ignition ter-
minal when the ignition switch is turned to Run posi-
tion. The CAB performs a system initialization
procedure at this point. Initialization consists of a
static and dynamic self check of system electrical
components.
The static check occurs after the ignition switch is
turned to Run position. The dynamic check occurs
when vehicle road speed reaches approximately 30
kph (18 mph). During the dynamic check, the CAB
briefly cycles the pump and solenoids to verify oper-
ation.
If an ABS component exhibits a fault during ini-
tialization, the CAB illuminates the amber warning
light and registers a fault code in the microprocessor
memory.
ELECTRONIC BRAKE DISTRIBUTION
The electronic brake distribution (EBD) functions
like a rear proportioning valve. The EBD system usesthe ABS system to control the slip of the rear wheels
in partial braking range. The braking force of the
rear wheels is controlled electronically by using the
inlet and outlet valves located in the HCU.
OPERATION
ANTILOCK BRAKING SYSTEM
During normal braking, the master cylinder, power
booster and wheel brake units all function as they
would in a vehicle without ABS. The HCU compo-
nents are not activated.
During antilock braking fluid pressure is modu-
lated according to wheel speed, degree of slip and
rate of deceleration. A sensor at each wheel converts
wheel speed into electrical signals. These signals are
transmitted to the CAB for processing and determi-
nation of wheel slip and deceleration rate.
The ABS system has three fluid pressure control
channels. The front brakes are controlled separately
and the rear brakes in tandem. A speed sensor input
signal indicating a high slip condition activates the
CAB antilock program. Two solenoid valves are used
in each antilock control channel. The valves are all
located within the HCU valve body and work in pairs
to either increase, hold, or decrease apply pressure as
needed in the individual control channels. The sole-
noid valves are not static during antilock braking.
They are cycled continuously to modulate pressure.
Solenoid cycle time in antilock mode can be mea-
sured in milliseconds.
ELECTRONIC BRAKE DISTRIBUTION
Upon entry into EBD the inlet valve for the rear
brake circuit is switched on so that the fluid supply
from the master cylinder is shut off. In order to
decrease the rear brake pressure the outlet valve for
5 - 32 BRAKES - ABSKJ

the rear brake circuit is pulsed. This allows fluid to
enter the low pressure accumulator (LPA) in the
HCU resulting in a drop in fluid pressure to the rear
brakes. In order to increase the rear brake pressure
the outlet valve is switched off and the inlet valve is
pulsed. This increases the pressure to the rear
brakes. This will continue until the required slip dif-
ference is obtained. At the end of EBD braking (no
brake application) the fluid in the LPA drains back to
the master cylinder by switching on the outlet valve
and draining through the inlet valve check valve. At
the same time the inlet valve is switched on to pre-
vent a hydraulic short circiut in case of another
brake application.The EBD will remain functional
during many ABS fault modes. If the red and amber
warning lamps are illuminated the EBD may have a
fault.
DIAGNOSIS AND TESTING - ANTILOCK
BRAKING SYSTEM
The ABS brake system performs several self-tests
every time the ignition switch is turned on and the
vehicle is driven. The CAB monitors the systems
input and output circuits to verify the system is oper-
ating correctly. If the on board diagnostic system
senses that a circuit is malfunctioning the system
will set a trouble code in its memory.
NOTE: An audible noise may be heard during the
self-test. This noise should be considered normal.NOTE: The MDS or DRB III scan tool is used to
diagnose the ABS system. For additional informa-
tion refer to the Electrical, Electronic Control Mod-
ules section. For test procedures refer to the
Chassis Diagnostic Manual.
STANDARD PROCEDURE - ABS BRAKE
BLEEDING
ABS system bleeding requires conventional bleed-
ing methods plus use of the DRB scan tool. The pro-
cedure involves performing a base brake bleeding,
followed by use of the scan tool to cycle and bleed the
HCU pump and solenoids. A second base brake bleed-
ing procedure is then required to remove any air
remaining in the system.
(1) Perform base brake bleeding,(Refer to 5 -
BRAKES - STANDARD PROCEDURE) OR (Refer to
5 - BRAKES - STANDARD PROCEDURE).
(2) Connect scan tool to the Data Link Connector.
(3) Select ANTILOCK BRAKES, followed by MIS-
CELLANEOUS, then ABS BRAKES. Follow the
instructions displayed. When scan tool displays TEST
COMPLETE, disconnect scan tool and proceed.
(4) Perform base brake bleeding a second time,(Re-
fer to 5 - BRAKES - STANDARD PROCEDURE) OR
(Refer to 5 - BRAKES - STANDARD PROCEDURE).
(5) Top off master cylinder fluid level and verify
proper brake operation before moving vehicle.
SPECIFICATIONS
TORQUE SPECIFICATIONS
DESCRIPTION N´m Ft. Lbs. In. Lbs.
Hydraulic Control
Unit/Controller Antilock
Brakes Mounting Nuts14.1 Ð 125
Hydraulic Control
Unit/Controller Antilock
Brakes Brake Lines20.3 Ð 180
Controller Antilock Brakes
Mounting Screws1.8 Ð 16
Wheel Speed Sensors
Front Mounting Bolt12 Ð 132
Wheel Speed Sensor
Rear Mounting Bolt9Ð80
KJBRAKES - ABS 5 - 33
BRAKES - ABS (Continued)