2002 JEEP LIBERTY brake system

GROUP TAB LOCATOR
Introduction
0Lubrication & Maintenance
2Suspension
2SSuspension
3Differential & Driveline
5Brakes
5SBrakes
6Clutch
7Cooling
7SCooling
8AAudio
8BChime/Buzzer
8EElectronic Control Modules
8FEngine Systems
8GHeated Systems
8HHorn
8IIgnition Control
8JInstrument Cluster
8LLamps
8LSLamps
8MMessage Systems
8NPower Systems
8ORestraints
8PSpeed Control
8QVehicle Theft Security
8RWipers/Washers
8WWiring
9Engine
9SEngine
11Exhaust System
11SExhaust System
13Frame & Bumpers
14Fuel System
19Steering
21Transmission and Transfer Case
22Tires/Wheels
23Body
24Heating & Air Conditioning
25Emissions Control
Component and System Index
2.4L Gas Component and System Index
Service Manual Comment Forms
NOTE: For New Vehicle Preparation information, see the separate
publication, 81-170-00003.
NOTE: Group names with the suffix(S(indicate groups pertaining to the
the 2.4L Gas Supplement

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

SUSPENSION
TABLE OF CONTENTS
page page
SUSPENSION
DIAGNOSIS AND TESTING - SUSPENSION
AND STEERING SYSTEM................1WHEEL ALIGNMENT......................3
FRONT.................................7
REAR.................................16
SUSPENSION
DIAGNOSIS AND TESTING - SUSPENSION AND
STEERING SYSTEM
CONDITION POSSIBLE CAUSES CORRECTION
FRONT END NOISE 1. Loose or worn wheel bearings. 1. Replace wheel bearings.
2. Loose or worn steering or
suspension components.2. Tighten or replace components as
necessary.
EXCESSIVE PLAY IN
STEERING1. Loose or worn wheel bearings. 1. Replace wheel bearings.
2. Loose or worn steering or
suspension components.2. Tighten or replace components as
necessary.
3. Loose or worn steering gear. 3. Adjust or replace steering gear.
FRONT WHEELS SHIMMY 1. Loose or worn wheel bearings. 1. Replace wheel bearings.
2. Loose or worn steering or
suspension components.2. Tighten or replace components as
necessary.
3. Tires worn or out of balance. 3. Replace or balance tires.
4. Alignment. 4. Align vehicle to specifications.
VEHICLE INSTABILITY 1. Loose or worn wheel bearings. 1. Replace wheel bearings.
2. Loose or worn steering or
suspension components.2. Tighten or replace components as
necessary.
3. Tire pressure. 3. Adjust tire pressure.
4. Alignment. 4. Align vehicle to specifications.
EXCESSIVE STEERING
EFFORT1. Loose or worn steering gear. 1. Adjust or replace steering gear.
2. Power steering fluid low. 2. Add fluid and repair leak.
3. Column coupler binding. 3. Replace coupler.
4. Tire pressure. 4. Adjust tire pressure.
5. Alignment. 5. Align vehicle to specifications.
VEHICLE PULLS TO ONE
SIDE DURING BRAKING1. Uneven tire pressure. 1. Adjust tire pressure.
2. Worn brake components. 2. Repair brakes as necessary.
3. Air in brake line. 3. Repair as necessary.
KJSUSPENSION 2 - 1

BRAKES
TABLE OF CONTENTS
page page
BRAKES - BASE........................... 1BRAKES - ABS........................... 32
BRAKES - BASE
TABLE OF CONTENTS
page page
BRAKES - BASE
DESCRIPTION..........................2
WARNING.............................2
DIAGNOSIS AND TESTING - BASE BRAKE
SYSTEM.............................3
STANDARD PROCEDURE
STANDARD PROCEDURE - PRESSURE
BLEEDING............................5
STANDARD PROCEDURE - MANUAL
BLEEDING............................6
SPECIFICATIONS
BRAKE COMPONENTS..................6
TORQUE.............................7
SPECIAL TOOLS
BASE BRAKES........................7
BRAKE LINES
DESCRIPTION..........................8
DIAGNOSIS AND TESTING - BRAKE LINE
AND HOSES..........................8
STANDARD PROCEDURE
STANDARD PROCEDURE - DOUBLE
INVERTED FLARING....................8
STANDARD PROCEDURE - ISO FLARING . . . 8
REMOVAL
REMOVAL - FRONT HOSE...............9
REMOVAL - REAR BRAKE HOSE..........9
INSTALLATION
INSTALLATION - FRONT BRAKE HOSE....10
INSTALLATION - REAR BRAKE HOSE......10
BRAKE PADS / SHOES
DESCRIPTION - REAR DRUM BRAKE.......10
OPERATION - REAR DRUM BRAKE.........11
REMOVAL
REMOVAL - FRONT BRAKE PADS.........11
REMOVAL - DRUM BRAKE SHOES........11
INSTALLATION
INSTALLATION - FRONT BRAKE PADS.....11INSTALLATION - DRUM BRAKE SHOES....11
ADJUSTMENTS
ADJUSTMENT - REAR DRUM BRAKE......12
DISC BRAKE CALIPERS
DESCRIPTION.........................13
OPERATION...........................14
REMOVAL.............................14
DISASSEMBLY.........................14
CLEANING............................16
INSPECTION..........................16
ASSEMBLY............................16
INSTALLATION.........................17
DISC BRAKE CALIPER ADAPTER
REMOVAL.............................18
INSTALLATION.........................18
ROTORS
DIAGNOSIS AND TESTING - DISC BRAKE
ROTOR .............................18
STANDARD PROCEDURE - DISC BRAKE
ROTOR .............................19
REMOVAL.............................19
INSTALLATION.........................19
JUNCTION BLOCK
DESCRIPTION.........................20
OPERATION...........................20
DIAGNOSIS AND TESTING -
PROPORTIONING VALVE...............20
REMOVAL.............................20
INSTALLATION.........................20
PEDAL
DESCRIPTION.........................20
OPERATION...........................20
REMOVAL.............................20
INSTALLATION.........................20
POWER BRAKE BOOSTER
DESCRIPTION.........................21
OPERATION...........................21
KJBRAKES 5 - 1

CAUTION: Never use gasoline, kerosene, alcohol,
motor oil, transmission fluid, or any fluid containing
mineral oil to clean the system components. These
fluids damage rubber cups and seals. Use only
fresh brake fluid or Mopar brake cleaner to clean or
flush brake system components. These are the only
cleaning materials recommended. If system contam-
ination is suspected, check the fluid for dirt, discol-
oration, or separation into distinct layers. Also
check the reservoir cap seal for distortion. Drain
and flush the system with new brake fluid if con-
tamination is suspected.
CAUTION: Use Mopar brake fluid, or an equivalent
quality fluid meeting SAE/DOT standards J1703 and
DOT 3. Brake fluid must be clean and free of con-
taminants. Use fresh fluid from sealed containers
only to ensure proper antilock component opera-
tion.
CAUTION: Use Mopar multi-mileage or high temper-
ature grease to lubricate caliper slide surfaces,
drum brake pivot pins, and shoe contact points on
the backing plates. Use multi-mileage grease or GE
661 or Dow 111 silicone grease on caliper slide pins
to ensure proper operation.
DIAGNOSIS AND TESTING - BASE BRAKE
SYSTEM
Base brake components consist of the brake shoes,
calipers, wheel cylinders, brake drums, rotors, brake
lines, master cylinder, booster, and parking brake
components.
Brake diagnosis involves determining if the prob-
lem is related to a mechanical, hydraulic, or vacuum
operated component.
The first diagnosis step is the preliminary check.
PRELIMINARY BRAKE CHECK
(1) Check condition of tires and wheels. Damaged
wheels and worn, damaged, or underinflated tires
can cause pull, shudder, vibration, and a condition
similar to grab.
(2) If complaint was based on noise when braking,
check suspension components. Jounce front and rear
of vehicle and listen for noise that might be caused
by loose, worn or damaged suspension or steering
components.
(3) Inspect brake fluid level and condition. Note
that the brake reservoir fluid level will decrease in
proportion to normal lining wear.Also note that
brake fluid tends to darken over time. This is
normal and should not be mistaken for contam-
ination.(a) If fluid level is abnormally low, look for evi-
dence of leaks at calipers, wheel cylinders, brake
lines, and master cylinder.
(b) If fluid appears contaminated, drain out a
sample to examine. System will have to be flushed
if fluid is separated into layers, or contains a sub-
stance other than brake fluid. The system seals
and cups will also have to be replaced after flush-
ing. Use clean brake fluid to flush the system.
(4) Check parking brake operation. Verify free
movement and full release of cables and pedal. Also
note if vehicle was being operated with parking
brake partially applied.
(5) Check brake pedal operation. Verify that pedal
does not bind and has adequate free play. If pedal
lacks free play, check pedal and power booster for
being loose or for bind condition. Do not road test
until condition is corrected.
(6) Check booster vacuum check valve and hose.
(7) If components checked appear OK, road test
the vehicle.
ROAD TESTING
(1) If complaint involved low brake pedal, pump
pedal and note if it comes back up to normal height.
(2) Check brake pedal response with transmission
in Neutral and engine running. Pedal should remain
firm under constant foot pressure.
(3) During road test, make normal and firm brake
stops in 25-40 mph range. Note faulty brake opera-
tion such as low pedal, hard pedal, fade, pedal pulsa-
tion, pull, grab, drag, noise, etc.
(4) Attempt to stop the vehicle with the parking
brake only and note grab, drag, noise, etc.
PEDAL FALLS AWAY
A brake pedal that falls away under steady foot
pressure is generally the result of a system leak. The
leak point could be at a brake line, fitting, hose, or
caliper/wheel cylinder. If leakage is severe, fluid will
be evident at or around the leaking component.
Internal leakage (seal by-pass) in the master cylin-
der caused by worn or damaged piston cups, may
also be the problem cause.
An internal leak in the ABS or RWAL system may
also be the problem with no physical evidence.
LOW PEDAL
If a low pedal is experienced, pump the pedal sev-
eral times. If the pedal comes back up worn linings,
rotors, drums, or rear brakes out of adjustment are
the most likely causes. The proper course of action is
to inspect and replace all worn component and make
the proper adjustments.
KJBRAKES - BASE 5 - 3
BRAKES - BASE (Continued)

SPONGY PEDAL
A spongy pedal is most often caused by air in the
system. However, thin brake drums or substandard
brake lines and hoses can also cause a spongy pedal.
The proper course of action is to bleed the system,
and replace thin drums and substandard quality
brake hoses if suspected.
HARD PEDAL OR HIGH PEDAL EFFORT
A hard pedal or high pedal effort may be due to
lining that is water soaked, contaminated, glazed, or
badly worn. The power booster or check valve could
also be faulty.
PEDAL PULSATION
Pedal pulsation is caused by components that are
loose, or beyond tolerance limits.
The primary cause of pulsation are disc brake
rotors with excessive lateral runout or thickness vari-
ation, or out of round brake drums. Other causes are
loose wheel bearings or calipers and worn, damaged
tires.
NOTE: Some pedal pulsation may be felt during
ABS activation.
BRAKE DRAG
Brake drag occurs when the lining is in constant
contact with the rotor or drum. Drag can occur at one
wheel, all wheels, fronts only, or rears only.
Drag is a product of incomplete brake shoe release.
Drag can be minor or severe enough to overheat the
linings, rotors and drums.
Minor drag will usually cause slight surface char-
ring of the lining. It can also generate hard spots in
rotors and drums from the overheat-cool down pro-
cess. In most cases, the rotors, drums, wheels and
tires are quite warm to the touch after the vehicle is
stopped.
Severe drag can char the brake lining all the way
through. It can also distort and score rotors and
drums to the point of replacement. The wheels, tires
and brake components will be extremely hot. In
severe cases, the lining may generate smoke as it
chars from overheating.
Common causes of brake drag are:
²Seized or improperly adjusted parking brake
cables.
²Loose/worn wheel bearing.
²Seized caliper or wheel cylinder piston.
²Caliper binding on corroded bushings or rusted
slide surfaces.
²Loose caliper mounting.
²Drum brake shoes binding on worn/damaged
support plates.
²Mis-assembled components.²Long booster output rod.
If brake drag occurs at all wheels, the problem
may be related to a blocked master cylinder return
port, or faulty power booster (binds-does not release).
BRAKE FADE
Brake fade is usually a product of overheating
caused by brake drag. However, brake overheating
and resulting fade can also be caused by riding the
brake pedal, making repeated high deceleration stops
in a short time span, or constant braking on steep
mountain roads. Refer to the Brake Drag information
in this section for causes.
BRAKE PULL
Front brake pull condition could result from:
²Contaminated lining in one caliper
²Seized caliper piston
²Binding caliper
²Loose caliper
²Rusty caliper slide surfaces
²Improper brake shoes
²Damaged rotor
A worn, damaged wheel bearing or suspension
component are further causes of pull. A damaged
front tire (bruised, ply separation) can also cause
pull.
A common and frequently misdiagnosed pull condi-
tion is where direction of pull changes after a few
stops. The cause is a combination of brake drag fol-
lowed by fade at one of the brake units.
As the dragging brake overheats, efficiency is so
reduced that fade occurs. Since the opposite brake
unit is still functioning normally, its braking effect is
magnified. This causes pull to switch direction in
favor of the normally functioning brake unit.
An additional point when diagnosing a change in
pull condition concerns brake cool down. Remember
that pull will return to the original direction, if the
dragging brake unit is allowed to cool down (and is
not seriously damaged).
REAR BRAKE GRAB OR PULL
Rear grab or pull is usually caused by improperly
adjusted or seized parking brake cables, contami-
nated lining, bent or binding shoes and support
plates, or improperly assembled components. This is
particularly true when only one rear wheel is
involved. However, when both rear wheels are
affected, the master cylinder or proportioning valve
could be at fault.
5 - 4 BRAKES - BASEKJ
BRAKES - BASE (Continued)

BRAKES DO NOT HOLD AFTER DRIVING THROUGH DEEP
WATER PUDDLES
This condition is generally caused by water soaked
lining. If the lining is only wet, it can be dried by
driving with the brakes very lightly applied for a
mile or two. However, if the lining is both soaked and
dirt contaminated, cleaning and/or replacement will
be necessary.
BRAKE LINING CONTAMINATION
Brake lining contamination is mostly a product of
leaking calipers or wheel cylinders, worn seals, driv-
ing through deep water puddles, or lining that has
become covered with grease and grit during repair.
Contaminated lining should be replaced to avoid fur-
ther brake problems.
WHEEL AND TIRE PROBLEMS
Some conditions attributed to brake components
may actually be caused by a wheel or tire problem.
A damaged wheel can cause shudder, vibration and
pull. A worn or damaged tire can also cause pull.
Severely worn tires with very little tread left can
produce a grab-like condition as the tire loses and
recovers traction. Flat-spotted tires can cause vibra-
tion and generate shudder during brake operation. A
tire with internal damage such as a severe bruise,
cut, or ply separation can cause pull and vibration.
BRAKE NOISES
Some brake noise is common with rear drum
brakes and on some disc brakes during the first few
stops after a vehicle has been parked overnight or
stored. This is primarily due to the formation of trace
corrosion (light rust) on metal surfaces. This light
corrosion is typically cleared from the metal surfaces
after a few brake applications causing the noise to
subside.
BRAKE SQUEAK/SQUEAL
Brake squeak or squeal may be due to linings that
are wet or contaminated with brake fluid, grease, or
oil. Glazed linings and rotors with hard spots can
also contribute to squeak. Dirt and foreign material
embedded in the brake lining will also cause squeak/
squeal.
A very loud squeak or squeal is frequently a sign of
severely worn brake lining. If the lining has worn
through to the brake shoes in spots, metal-to-metal
contact occurs. If the condition is allowed to continue,
rotors and drums can become so scored that replace-
ment is necessary.
BRAKE CHATTER
Brake chatter is usually caused by loose or worn
components, or glazed/burnt lining. Rotors with hard
spots can also contribute to chatter. Additional causesof chatter are out-of-tolerance rotors, brake lining not
securely attached to the shoes, loose wheel bearings
and contaminated brake lining.
THUMP/CLUNK NOISE
Thumping or clunk noises during braking are fre-
quentlynotcaused by brake components. In many
cases, such noises are caused by loose or damaged
steering, suspension, or engine components. However,
calipers that bind on the slide surfaces can generate
a thump or clunk noise. In addition, worn out,
improperly adjusted, or improperly assembled rear
brake shoes can also produce a thump noise.
STANDARD PROCEDURE
STANDARD PROCEDURE - PRESSURE
BLEEDING
Use Mopar brake fluid, or an equivalent quality
fluid meeting SAE J1703-F and DOT 3 standards
only. Use fresh, clean fluid from a sealed container at
all times.
Do not pump the brake pedal at any time while
bleeding. Air in the system will be compressed into
small bubbles that are distributed throughout the
hydraulic system. This will make additional bleeding
operations necessary.
Do not allow the master cylinder to run out of fluid
during bleed operations. An empty cylinder will allow
additional air to be drawn into the system. Check the
cylinder fluid level frequently and add fluid as
needed.
Bleed only one brake component at a time in the
following sequence:
²Master Cylinder
²Combination Valve
²Right Rear Wheel
²Left Rear Wheel
²Right Front Wheel
²Left Front Wheel
Follow the manufacturers instructions carefully
when using pressure equipment. Do not exceed the
tank manufacturers pressure recommendations. Gen-
erally, a tank pressure of 15-20 psi is sufficient for
bleeding.
Fill the bleeder tank with recommended fluid and
purge air from the tank lines before bleeding.
Do not pressure bleed without a proper master cyl-
inder adapter. The wrong adapter can lead to leak-
age, or drawing air back into the system. Use
adapter provided with the equipment or Adapter
6921.
KJBRAKES - BASE 5 - 5
BRAKES - BASE (Continued)

STANDARD PROCEDURE - MANUAL BLEEDING
Use Mopar brake fluid, or an equivalent quality
fluid meeting SAE J1703-F and DOT 3 standards
only. Use fresh, clean fluid from a sealed container at
all times.
Do not pump the brake pedal at any time while
bleeding. Air in the system will be compressed into
small bubbles that are distributed throughout the
hydraulic system. This will make additional bleeding
operations necessary.
Do not allow the master cylinder to run out of fluid
during bleed operations. An empty cylinder will allow
additional air to be drawn into the system. Check the
cylinder fluid level frequently and add fluid as
needed.
Bleed only one brake component at a time in the
following sequence:
²Master Cylinder
²Combination Valve
²Right Rear Wheel
²Left Rear Wheel
²Right Front Wheel
²Left Front Wheel
(1) Remove reservoir filler caps and fill reservoir.
(2) If calipers, or wheel cylinders were overhauled,
open all caliper and wheel cylinder bleed screws.
Then close each bleed screw as fluid starts to drip
from it. Top off master cylinder reservoir once more
before proceeding.
(3) Attach one end of bleed hose to bleed screw
and insert opposite end in glass container partially
filled with brake fluid (Fig. 1). Be sure end of bleed
hose is immersed in fluid.
(4) Open up bleeder, then have a helper press
down the brake pedal. Once the pedal is down close
the bleeder. Repeat bleeding until fluid stream is
clear and free of bubbles. Then move to the next
wheel.
SPECIFICATIONS
BRAKE COMPONENTS
SPECIFICATIONS
DESCRIPTION SPECIFICATION
Disc Brake Rotor
VentilatedMax. Runout
0.12 mm (0.005 in.)
Disc Brake Rotor
VentilatedMax. Thickness Variation
0.013 mm (0.0005 in.)
Disc Brake Rotor
VentilatedMin. Thickness
22.7 mm (0.8937 in.)
Disc Brake Caliper Sliding
Brake Drum 9 in. or 10 in.
Brake Booster Dual Diaphragm
Fig. 1 Bleed Hose Setup
1 - BLEED HOSE
2 - FLUID CONTAINER PARTIALLY FILLED WITH FLUID
5 - 6 BRAKES - BASEKJ
BRAKES - BASE (Continued)