2003 JEEP GRAND CHEROKEE 23 Body

ADJUSTABLE PEDAL SWITCH
REMOVAL
(1) Remove the steering column opening cover
(Fig. 2)(Refer to 23 - BODY/INSTRUMENT PANEL/
STEERING COLUMN OPENING COVER - REMOV-
AL).
(2) Disconnect the electrical connector from the
adjustable pedal switch.
(3) Remove the switch from the steering column
opening cover by squeezing the retaining clips
together and pushing the switch outwards (Fig. 3).
INSTALLATION
(1) Install the switch to the steering column open-
ing cover by pushing the switch inwards seating the
retaining clips to the steering column opening cover
(Fig. 3).
(2) Reconnect the electrical connector to the
adjustable pedal switch.
(3) Install the steering column opening cover (Fig.
2)(Refer to 23 - BODY/INSTRUMENT PANEL/
STEERING COLUMN OPENING COVER - INSTAL-
LATION).
BRAKE LINES
DESCRIPTION
Flexible rubber hose is used at both front brakes,
rear brakes and at the rear axle junction block. Dou-
ble walled steel tubing is used. Double inverted style
and ISO style flares are used on the brake lines.
DIAGNOSIS AND TESTING - BRAKE HOSES
AND LINES
Flexible rubber hose is used at both front and rear
brakes and at the rear axle junction block. Inspect
the hoses whenever the brake system is serviced, at
every engine oil change, or whenever the vehicle is in
for service.
Inspect the hoses for surface cracking, scuffing, or
worn spots. Replace any brake hose immediately if
the fabric casing of the hose is exposed due to cracks
or abrasions.
Also check brake hose installation. Faulty installa-
tion can result in kinked, twisted hoses, or contact
with the wheels and tires or other chassis compo-
nents. All of these conditions can lead to scuffing,
cracking and eventual failure.
The steel brake lines should be inspected periodi-
cally for evidence of corrosion, twists, kinks, leaks, or
other damage. Heavily corroded lines will eventually
rust through causing leaks. In any case, corroded or
damaged brake lines should be replaced.
Factory replacement brake lines and hoses are rec-
ommended to ensure quality, correct length and supe-
rior fatigue life. Care should be taken to make sure
that brake line and hose mating surfaces are clean
and free from nicks and burrs. Also remember that
right and left brake hoses are not interchangeable.
Use new copper gaskets at all caliper connections.
Be sure brake line connections are properly made
(not cross threaded) and tightened to recommended
torque.
Fig. 2 STEERING COLUMN OPENING COVER
REMOVAL/INSTALL
1 - INSTRUMENT PANEL TOP PAD
2 - STEERING COLUMN OPENING COVER
3 - SCREW (3)
Fig. 3 ADJUSTABLE PEDAL SWITCH
1 - RETAINING CLIPS
2 - ELECTRICAL CONNECTION
5 - 8 BRAKES - BASEWJ

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 with
reservoir, caliper seals, HCU and all hydraulic fluid
hoses.
SPECIFICATIONS
BRAKE FLUID
The brake fluid used in this vehicle must conform
to DOT 3 specifications and SAE J1703 standards.
No other type of brake fluid is recommended or
approved for usage in the vehicle brake system. Use
only Mopar brake fluid or an equivalent from a
tightly sealed container.
CAUTION: Never use reclaimed brake fluid or fluid
from an container which has been left open. An
open container of brake fluid will absorb moisture
from the air and contaminate the fluid.
CAUTION: Never use any type of a petroleum-based
fluid in the brake hydraulic system. Use of such
type fluids will result in seal damage of the vehicle
brake hydraulic system causing a failure of the
vehicle brake system. Petroleum based fluids would
be items such as engine oil, transmission fluid,
power steering fluid, etc.
FLUID RESERVOIR
REMOVAL
(1) Remove reservoir cap and remove fluid with a
cleansuction gun.
(2) Remove the wire connector from the brake fluid
level sensor.
(3) Insert the tool (Fig. 47) provided with the res-
ervoir to release the reservoir retaining tabs.
(4) Pull the reservoir straight up out of the cylin-
der.
(5) Remove and discard grommets from the cylin-
der body.
INSTALLATION
(1) Lubricate new grommets with clean brake
fluid. Install new grommets into the cylinder body.
CAUTION: Do not use tools to install the grommets.
Tools may cut, or tear the grommets. Install the
grommets using finger pressure only.(2) Start reservoir in grommets then press the res-
ervoir straight down to seat the reservoir into the
cylinder grommets.
CAUTION: Do not rock the reservoir during installa-
tion.
(3) Verify retaining tabs are seated.
(4) Install the wire connector to the brake fluid
level sensor.
(5) Fill master cylinder.
MASTER CYLINDER
DESCRIPTION
The master cylinder body is made of aluminum
and contains a primary and secondary piston assem-
bly. The cylinder body including the piston assem-
blies are not serviceable. If diagnosis indicates an
internal problem with the cylinder body, it must be
replaced as an assembly. The master cylinder has a
removable reservoir and fluid level indicator. The res-
ervoir, reservoir grommets, reservoir cap and fluid
level switch are the only replaceable parts on the
master cylinder.
Fig. 47 Release Tool
1 - RESERVOIR
2 - RELEASE TOOL
3 - RETAINING TABS
WJBRAKES - BASE 5 - 23
FLUID (Continued)

(2) Remove nut from pedal shaft.
(3) Slide pedal shaft out and remove brake pedal.
(4) Remove pedal bushings (Fig. 54) if they are to
be replaced.
REMOVAL - ADJUSTABLE PEDALS
NOTE: If possible put the pedals in the full forward
position.
(1) Disconnect the negative battery cable.
(2) Remove the cluster bezel (Refer to 23 - BODY/
INSTRUMENT PANEL/CLUSTER BEZEL - REMOV-
AL).
(3) Remove the steering column opening cover
(Refer to 23 - BODY/INSTRUMENT PANEL/STEER-
ING COLUMN OPENING COVER - REMOVAL).
(4) Disconnect the module electrical connector.
(5) Remove the brake light switch.
(6) Disconnect the booster rod clip (Fig. 53).
(7) Disconnect the accelerator cable from the
pedal.
(8) Lock the steering wheel into place.
(9) Remove the lower steering shaft pinch bolt
(Fig. 56).
(10) Separate the lower shaft coupler and push for-
ward (Fig. 56).
(11) Remove the two pedal bracket upper nuts
(Fig. 55).
(12) Remove the brake booster nuts (Fig. 56).
(13) Remove the accelerator pedal nuts (Fig. 57).(14) Remove the ICU mounting bracket nuts and
bolts and move the ICU and booster forward this will
allow enough clearance to remove the adjustable
pedal bracket from over the booster push rod.
(15) Remove the pedal from the vehicle (Fig. 56).
(16) Transfer the module if needed.
Fig. 54 Pedal Bushings
1 - BUSHING
2 - BUSHING
3 - SHAFT NUT
4 - PEDAL SHAFT
Fig. 55 UPPER MOUNTING NUTS
1 - UPPER MOUNTING STUDS
2 - ACCELERATOR MOUNTING STUDS
3 - UPPER MOUNTING NUT
4 - MOTOR
5 - ADJUSTABLE PEDAL BRACKET
Fig. 56 ADJUSTABLE PEDAL BRACKET
1 - BRAKE LIGHT SWITCH
2 - STEERING COLUMN
3 - ACCELERATOR PEDAL
4 - ADJUSTABLE PEDALS MOUNTING BRACKET
5 - BRAKE PEDAL
6 - MOTOR MOUNTING BRACKET
7 - BRAKE BOOSTER MOUNTING NUTS
(4)
WJBRAKES - BASE 5 - 27
PEDAL (Continued)

INSTALLATION
INSTALLATION - NON-ADJUSTABLE PEDAL
(1) Lubricate bushings, pedal shaft and pedal pin
with Mopar multi-mileage grease.
(2) Install bushings into pedal.
(3) Position pedal in bracket and install pedal
shaft in support and through pedal.
(4) Install new nut on pedal shaft and tighten to
27 N´m (20 ft. lbs.).
NOTE: Pedal shaft nut should not be reused.
(5) Install booster push rod on pedal pin and
install retainer clip on pedal pin.
(6) Check and adjust stop lamp switch if necessary.
INSTALLATION - ADJUSTABLE PEDALS
(1) Install the pedal to the vehicle (Fig. 56).
(2) Reposition the ICU and booster, Install the
ICU mounting bracket nuts and bolts.
28 N
(3) Install the brake booster nuts. Tighten to 28
N´m ( 21 ft. lbs.). (Fig. 56).
(4) Install the pedal bracket upper nuts. Tighten
to 12 N´m ( 9 ft. lbs.). (Fig. 56).
(5) Install the accelerator pedal nuts. Tighten to
28 N´m ( 21 ft. lbs.). (Fig. 57).
(6) Install the lower steering shaft coupler over the
shaft (Fig. 56).
(7) Install the lower steering shaft pinch bolt (Fig.
56).
(8) Unlock the steering wheel.
(9) Reconnect the accelerator cable to the pedal
(Fig. 56).(10) Reconnect the booster rod clip (Fig. 56).
(11) Install the brake light switch.
(12) Reconnect the module electrical connector.
(13) Install the steering column opening cover
(Refer to 23 - BODY/INSTRUMENT PANEL/STEER-
ING COLUMN OPENING COVER - INSTALLA-
TION).
(14) Install the cluster bezel (Refer to 23 - BODY/
INSTRUMENT PANEL/CLUSTER BEZEL -
INSTALLATION).
(15) Reconnect the negative battery cable.
PEDAL MOTOR
REMOVAL
(1) Disconnect the negative battery cable.
(2) Remove the cluster bezel (Refer to 23 - BODY/
INSTRUMENT PANEL/CLUSTER BEZEL - REMOV-
AL).
(3) Remove the steering column opening cover
(Refer to 23 - BODY/INSTRUMENT PANEL/STEER-
ING COLUMN OPENING COVER - REMOVAL).
(4) Remove the two mounting screws (Fig. 58).
(5) Disconnect the electrical connector (Fig. 58).
(6) Remove the adjustable pedal motor (Fig. 58).
INSTALLATION
(1) Install the adjustable pedal motor (Fig. 58).
(2) Reconnect the electrical connector (Fig. 58).
(3) Install the two mounting screws (Fig. 58).
(4) Install the steering column opening cover
(Refer to 23 - BODY/INSTRUMENT PANEL/STEER-
ING COLUMN OPENING COVER - INSTALLA-
TION).
Fig. 57 ACCELERATOR MOUNTING BRACKET
1 - ACCELERATOR MOUNTING NUTS
2 - ADJUSTABLE PEDALS BRACKET
3 - ACCELERATOR PEDAL
Fig. 58 ADJUSTABLE PEDALS MOTOR
1 - ELECTRICAL CONNECTOR
2 - PEDALS MOTOR
3 - MOUNTING SCREWS HOLES
5 - 28 BRAKES - BASEWJ
PEDAL (Continued)

(5) Install the cluster bezel (Refer to 23 - BODY/
INSTRUMENT PANEL/CLUSTER BEZEL -
INSTALLATION).
(6) Reconnect the negative battery cable.
POWER BRAKE BOOSTER
DESCRIPTION
The booster assembly consists of a housing divided
into separate chambers by two internal diaphragms.
The outer edge of each diaphragm is attached to the
booster housing.
Two push rods are used in the booster. The pri-
mary push rod connects the booster to the brake
pedal. The secondary push rod connects the booster
to the master cylinder to stroke the cylinder pistons.
OPERATION
The atmospheric inlet valve is opened and closed
by the primary push rod. Booster vacuum supply is
through a hose attached to an intake manifold fittingat one end and to the booster check valve at the
other. The vacuum check valve in the booster housing
is a one-way device that prevents vacuum leak back.
Power assist is generated by utilizing the pressure
differential between normal atmospheric pressure
and a vacuum. The vacuum needed for booster oper-
ation is taken directly from the engine intake mani-
fold. The entry point for atmospheric pressure is
through a filter and inlet valve at the rear of the
housing (Fig. 59) .
The chamber areas forward of the booster dia-
phragms are exposed to vacuum from the intake
manifold. The chamber areas to the rear of the dia-
phragms, are exposed to normal atmospheric pres-
sure of 101.3 kilopascals (14.7 pounds/square in.).
Brake pedal application causes the primary push
rod to open the atmospheric inlet valve. This exposes
the area behind the diaphragms to atmospheric pres-
sure. The resulting pressure differential provides the
extra apply force for power assist.
The booster check valve, check valve grommet and
booster seals are serviceable.
WJBRAKES - BASE 5 - 29
PEDAL MOTOR (Continued)

CABLES
REMOVAL
REMOVAL - FRONT PARKING BRAKE CABLE
(1) Remove center console,(Refer to 23 - BODY/IN-
TERIOR/FLOOR CONSOLE - REMOVAL).
(2) Lift up rear seat and carpet covering the park-
ing brake cables.
(3) Place a screw driver through the front cable
eyelet (Fig. 66) and pry back on the front cable.
(4) Have an assistant pry down the lock out spring
through the hole in the side of the park brake lever
(Fig. 67) with a small screw driver. Then slowly
release the front cable.
NOTE: Their should be slack in the cable if the lock
out spring is engaged.
(5) Disengage front cable end from the equalizer
(Fig. 68).
(6) Disengage front cable end from the parking
brake lever.
(7) Remove the front carpet,(Refer to 23 - BODY/
INTERIOR/CARPETS AND FLOOR MATS -
REMOVAL).
(8) Remove front cable retainer nuts (Fig. 69) from
the floor pan.
Fig. 66 Front Cable Eyelet
1 - REAR CABLES
2 - FRONT CABLE EYELET
3 - FRONT CABLE
4 - EQUALIZER
Fig. 67 Lock Out Spring
1 - LOCK OUT SPRING
Fig. 68 Cable Equalizer
1 - EQUALIZER
2 - FRONT CABLE
Fig. 69 Front Parking Brake Cable
1 - RETAINER NUT
2 - FLOOR PAN
3 - FRONT CABLE
WJBRAKES - BASE 5 - 35

(9) Compress the cable retainers with a 13 mm
wrench (Fig. 70). Remove the cable from parking
brake lever bracket and equalizer bracket.
REMOVAL - REAR PARKING BRAKE CABLES
(1) Remove center console, (Refer to 23 - BODY/
INTERIOR/FLOOR CONSOLE - REMOVAL).
(2) Lift up rear seat and carpet covering the park-
ing brake cables.
(3) Place a screw driver through the front cable
eyelet (Fig. 71) and pry back on the front cable.(4) Have an assistant pry down the lock out spring
through the hole in the side of the park brake lever
(Fig. 72) with a small screw driver. Then slowly
release the front cable.
NOTE: Their should be slack in the cable if the lock
out spring is engaged.
(5) Disengage rear cables ends from the equalizer.
(6) Compress the cable retainers with a 13 mm
wrench (Fig. 73) and remove the cable from equalizer
bracket.
Fig. 70 Brake Lever Bracket
1 - FRONT CABLE
2 - WRENCH
Fig. 71 Front Cable Eyelet
1 - REAR CABLES
2 - FRONT CABLE EYELET
3 - FRONT CABLE
4 - EQUALIZER
Fig. 72 Lock Out Spring
1 - LOCK OUT SPRING
Fig. 73 Cable Retainers
1 - CABLE RETAINER
2 - WRENCH
3 - FRONT CABLE
4 - REAR CABLES
5 - 36 BRAKES - BASEWJ
CABLES (Continued)

(7) Raise and support the vehicle.
(8) Remove the wheel and tire assemblies.
(9) Remove the brake calipers, caliper anchors and
rotors.
(10) Remove the ABS sensor wiring harness (Fig.
74)from the rear brake cables.
(11) Remove the cable retainer bolts (Fig. 74) from
the rear spring pads.
(12) Pull the cables out of the upper suspension
arm brackets.
(13) Push the cable in and lift up the end of cable
with a small screw driver to disengage the cable from
the parking brake actuator (Fig. 75).
(14) Remove the cable from the vehicle.
INSTALLATION
INSTALLATION - FRONT PARKING BRAKE
CABLE
(1) Install thecable into the parking brake lever
bracket and equalizer bracket.
(2) Install the front cable to the floor pan and
install retainer nuts.
(3) Engage the front cable ends to the parking
brake lever and equalizer.
(4) Install the front carpet, (Refer to 23 - BODY/
INTERIOR/CARPETS AND FLOOR MATS -
INSTALLATION).
(5) Pull on the lever to release the lock out spring.
(6) Install the center console, (Refer to 23 - BODY/
INTERIOR/FLOOR CONSOLE - INSTALLATION).
(7) Fold down the rear carpet cover and rear seat.
INSTALLATION - REAR PARKING BRAKE
CABLES
(1) Install the cables through the caliper anchor
mount. Then push the end of cable strand in to
engage the cable end to the parking brake actuator.
(2) Feed the other end of the cables through the
body and into the equalizer bracket (Fig. 76).
Fig. 74 Left Rear Parking Brake Cable
1 - CABLE BRACKET
2 - UPPER SUSPENSION ARM
3 - PARKING BRAKE CABLE
4 - CABLE RETAINER
5 - ABS SENSOR WIRING
Fig. 75 Parking Brake
1 - CABLE END
2 - SCREW DRIVER
3 - PARKING BRAKE ACTUATOR
4 - BRAKE SHOES
Fig. 76 Equalizer Bracket
1 - EQUALIZER
2 - RIGHT REAR CABLE
3 - LEFT REAR CABLE
4 - FRONT CABLE
WJBRAKES - BASE 5 - 37
CABLES (Continued)