oil capacity JEEP GRAND CHEROKEE 2003 WJ / 2.G User Guide

SPARE TIRE
DESCRIPTION - SPARE / TEMPORARY TIRE
The temporary spare tire is designed for emer-
gency use only. The original tire should be repaired
or replaced at the first opportunity, then reinstalled.
Do not exceed speeds of 50 M.P.H. when using the
temporary spare tire. Refer to Owner's Manual for
complete details.
WHEELS
DESCRIPTION
The rim size is on the vehicle safety certification
label located on the drivers door shut face. The size
of the rim is determined by the drivetrain package.
Original equipment wheels/rims are designed for
operation up to the specified maximum vehicle capac-
ity.
All models use stamped steel, cast aluminum or
forged aluminum wheels. Every wheel has raised sec-
tions between the rim flanges and rim drop well
called safety humps (Fig. 18) .
Initial inflation of the tire forces the bead over
these raised sections. In case of rapid loss of air pres-
sure, the raised sections help hold the tire on the
wheel.
The wheel studs and nuts are designed for specific
applications. All aluminum and some steel wheels
have wheel stud nuts with an enlarged nose. This
enlarged nose is necessary to ensure proper retentionof the wheels. Do not use replacement studs or nuts
with a different design or lesser quality.
DIAGNOSIS AND TESTING - WHEEL
INSPECTION
Inspect wheels for:
²Excessive run out
²Dents or cracks
²Damaged wheel lug nut holes
²Air Leaks from any area or surface of the rim
NOTE: Do not attempt to repair a wheel by hammer-
ing, heating or welding.
If a wheel is damaged an original equipment
replacement wheel should be used. When obtaining
replacement wheels, they should be equivalent in
load carrying capacity. The diameter, width, offset,
pilot hole and bolt circle of the wheel should be the
same as the original wheel.
WARNING: FAILURE TO USE EQUIVALENT
REPLACEMENT WHEELS MAY ADVERSELY
AFFECT THE SAFETY AND HANDLING OF THE
VEHICLE. USED WHEELS ARE NOT RECOM-
MENDED. THE SERVICE HISTORY OF THE WHEEL
MAY HAVE INCLUDED SEVERE TREATMENT OR
VERY HIGH MILEAGE. THE RIM COULD FAIL WITH-
OUT WARNING.
STANDARD PROCEDURE - WHEEL
REPLACEMENT
The wheel studs and nuts are designed for specific
applications. They must be replaced with equivalent
parts. Do not use replacement parts of lesser quality
or a substitute design. All aluminum and some steel
wheels have wheel stud nuts which feature an
enlarged nose. This enlarged nose is necessary to
ensure proper retention of the aluminum wheels.
NOTE: Do not use chrome plated lug nuts with
chrome plated wheels.
Before installing the wheel, be sure to remove any
build up of corrosion on the wheel mounting surfaces.
Ensure wheels are installed with good metal-to-metal
contact. Improper installation could cause loosening
of wheel nuts. This could affect the safety and han-
dling of your vehicle.
To install the wheel, first position it properly on
the mounting surface. All wheel nuts should then be
tightened just snug. Gradually tighten them in
sequence to the proper torque specification.Never
use oil or grease on studs or nuts.
Wheels must be replaced if they have:
²Excessive runout
Fig. 18 Safety Rim
1 - FLANGE
2 - RIDGE
3 - WELL
22 - 10 TIRES/WHEELSWJ

gap should be between 0.35 to 0.65 millimeter (0.014
to 0.026 inch). If the proper air gap is not obtained,
add or subtract shims as needed until the desired air
gap is obtained.
(9) Install the compressor shaft bolt. Tighten the
bolt to 13 N´m (115 in. lbs.).
NOTE: The shims may compress after tightening
the shaft bolt. Check the air gap in four or more
places to verify the air gap is still correct. Spin the
pulley before performing a final check of the air
gap.
(10) To complete the installation, (Refer to 24 -
HEATING & AIR CONDITIONING/PLUMBING/A/C
COMPRESSOR - INSTALLATION)
A/C COMPRESSOR CLUTCH
RELAY
DESCRIPTION
The compressor clutch relay is a International
Standards Organization (ISO) micro-relay. The termi-
nal designations and functions are the same as a con-
ventional ISO relay. However, the micro-relay
terminal orientation (footprint) is different, the cur-
rent capacity is lower, and the relay case dimensions
are smaller than those of the conventional ISO relay.
OPERATION
The compressor clutch relay is a electromechanical
device that switches battery current to the compres-
sor clutch coil when the Powertrain Control Module
(PCM) grounds the coil side of the relay. The PCM
responds to inputs from the a/c compressor switch on
the a/c heater control panel, the Automatic Zone Con-
trol (AZC) control module (if the vehicle is so
equipped), the a/c fin probe, and the a/c high pres-
sure transducer. (Refer to 24 - HEATING & AIR
CONDITIONING/CONTROLS/A/C COMPRESSOR
CLUTCH RELAY - DIAGNOSIS AND TESTING)
The compressor clutch relay is located in the Power
Distribution Center (PDC) in the engine compart-
ment. Refer to the PDC label for relay identification
and location.
The compressor clutch relay cannot be repaired
and, if faulty or damaged, it must be replaced.
DIAGNOSIS AND TESTING - A/C COMPRESSOR
CLUTCH RELAY
For circuit descriptions and diagrams, refer to the
appropriate wiring information.
The compressor clutch relay (Fig. 10) is located in
the Power Distribution Center (PDC). Refer to the
PDC label for relay identification and location.Remove the relay from the PDC to perform the fol-
lowing tests:
(1) A relay in the de-energized position should
have continuity between terminals 87A and 30, and
no continuity between terminals 87 and 30. If OK, go
to Step 2. If not OK, replace the faulty relay.
(2) Resistance between terminals 85 and 86 (elec-
tromagnet) should be 75   5 ohms. If OK, go to Step
3. If not OK, replace the faulty relay.
(3) Connect a battery to terminals 85 and 86.
There should now be continuity between terminals
30 and 87, and no continuity between terminals 87A
and 30. If OK, see the Relay Circuit Test procedure
in this group. If not OK, replace the faulty relay.
RELAY CIRCUIT TEST
For circuit descriptions and diagrams, refer to the
appropriate wiring information..
(1) The relay common feed terminal cavity (30) is
connected to fused battery feed. There should be bat-
tery voltage at the cavity for relay terminal 30 at all
times. If OK, go to Step 2. If not OK, repair the open
circuit to the fuse in the PDC as required.
(2) The relay normally closed terminal (87A) is not
used in this application. Go to Step 3.
(3) The relay normally open terminal cavity (87) is
connected to the compressor clutch coil. There should
be continuity between this cavity and the A/C com-
pressor clutch relay output circuit cavity of the com-
pressor clutch coil wire harness connector. If OK, go
to Step 4. If not OK, repair the open circuit as
required.
(4) The relay coil battery terminal (86) is con-
nected to the fused ignition switch output (run/start)
circuit. There should be battery voltage at the cavity
for relay terminal 86 with the ignition switch in the
On position. If OK, go to Step 5. If not OK, repair the
Fig. 10 A/C COMPRESSOR CLUTCH RELAY
30 - COMMON FEED
85 - COIL GROUND
86 - COIL BATTERY
87 - NORMALLY OPEN
87A - NORMALLY CLOSED
24 - 16 CONTROLSWJ
A/C COMPRESSOR CLUTCH (Continued)

PLUMBING
TABLE OF CONTENTS
page page
PLUMBING
DESCRIPTION - REFRIGERANT LINE.......52
OPERATION - REFRIGERANT LINE.........52
WARNING.............................52
CAUTION
CAUTION...........................53
REFRIGERANT HOSES/LINES/TUBES
PRECAUTIONS.......................53
DIAGNOSIS AND TESTING - REFRIGERANT
SYSTEM LEAKS......................54
STANDARD PROCEDURE
STANDARD PROCEDURE - REFRIGERANT
SYSTEM SERVICE EQUIPMENT..........54
STANDARD PROCEDURE - REFRIGERANT
RECOVERY..........................55
STANDARD PROCEDURE - REFRIGERANT
SYSTEM EVACUATE...................55
STANDARD PROCEDURE - REFRIGERANT
SYSTEM CHARGE.....................56
SPECIFICATIONS
CHARGE CAPACITY...................57
A/C COMPRESSOR
DESCRIPTION
DESCRIPTION - A/C COMPRESSOR.......57
DESCRIPTION - HIGH PRESSURE RELIEF
VALVE..............................57
OPERATION
OPERATION - A/C COMPRESSOR........57
OPERATION - HIGH PRESSURE RELIEF
VALVE..............................57
DIAGNOSIS AND TESTING - COMPRESSOR
NOISE..............................58
REMOVAL
REMOVAL...........................58
REMOVAL - 2.7L TURBO DIESEL.........60
INSTALLATION
INSTALLATION.......................61
INSTALLATION - 2.7L TURBO DIESEL......61
A/C CONDENSER
DESCRIPTION.........................62
OPERATION...........................62
REMOVAL.............................62
INSTALLATION.........................63
A/C DISCHARGE LINE
REMOVAL
REMOVAL - 2.7L TURBO DIESEL.........63
REMOVAL...........................64INSTALLATION
INSTALLATION - 2.7L TURBO DIESEL......64
INSTALLATION.......................65
A/C EXPANSION VALVE
DESCRIPTION.........................65
OPERATION...........................65
DIAGNOSIS AND TESTING - A/C EXPANSION
VALVE ..............................65
REMOVAL.............................66
INSTALLATION.........................66
LIQUID LINE
REMOVAL
REMOVAL...........................66
REMOVAL - 2.7L TURBO DIESEL.........66
INSTALLATION
INSTALLATION.......................66
INSTALLATION - 2.7L TURBO DIESEL......67
SUCTION LINE
REMOVAL
REMOVAL...........................67
REMOVAL - 2.7L TURBO DIESEL.........68
INSTALLATION
INSTALLATION.......................68
INSTALLATION - 2.7L TURBO DIESEL......69
A/C EVAPORATOR
DESCRIPTION.........................69
OPERATION...........................69
REMOVAL.............................69
INSTALLATION.........................70
HEATER CORE
DESCRIPTION.........................71
OPERATION...........................71
REMOVAL.............................71
INSTALLATION.........................71
RECEIVER / DRIER
DESCRIPTION.........................72
OPERATION...........................72
REMOVAL.............................73
INSTALLATION.........................73
REFRIGERANT
DESCRIPTION.........................75
OPERATION...........................75
REFRIGERANT OIL
DESCRIPTION.........................75
OPERATION...........................75
STANDARD PROCEDURE - REFRIGERANT
OIL LEVEL...........................75
WJPLUMBING 24 - 51

VISCOUS HEATER
DESCRIPTION
DESCRIPTION........................76
DESCRIPTION - VISCOUS HEATER
CLUTCH............................76
OPERATION
OPERATION - VISCOUS HEATER.........76
OPERATION - VISCOUS HEATER CLUTCH . . 76REMOVAL
REMOVAL - VISCOUS HEATER...........76
REMOVAL - VISCOUS HEATER CLUTCH . . . 76
INSTALLATION
INSTALLATION.......................78
INSTALLATION - VISCOUS HEATER
CLUTCH............................78
PLUMBING
DESCRIPTION - REFRIGERANT LINE
The refrigerant lines and hoses are used to carry
the refrigerant between the various air conditioning
system components. A barrier hose design with a
nylon tube, which is sandwiched between rubber lay-
ers, is used for the R-134a air conditioning system on
this vehicle. This nylon tube helps to further contain
the R-134a refrigerant, which has a smaller molecu-
lar structure than R-12 refrigerant. The ends of the
refrigerant hoses are made from lightweight alumi-
num or steel, and commonly use braze-less fittings.
Any kinks or sharp bends in the refrigerant plumb-
ing will reduce the capacity of the entire air condi-
tioning system. Kinks and sharp bends reduce the
flow of refrigerant in the system. A good rule for the
flexible hose refrigerant lines is to keep the radius of
all bends at least ten times the diameter of the hose.
In addition, the flexible hose refrigerant lines should
be routed so they are at least 80 millimeters (3
inches) from the exhaust manifold.
OPERATION - REFRIGERANT LINE
High pressures are produced in the refrigerant sys-
tem when the air conditioning compressor is operat-
ing. Extreme care must be exercised to make sure
that each of the refrigerant system connections is
pressure-tight and leak free. It is a good practice to
inspect all flexible hose refrigerant lines at least once
a year to make sure they are in good condition and
properly routed.
The refrigerant lines and hoses cannot be repaired
and, if faulty or damaged, they must be replaced.
WARNING
WARNING: THE AIR CONDITIONING SYSTEM CON-
TAINS REFRIGERANT UNDER HIGH PRESSURE.
SEVERE PERSONAL INJURY MAY RESULT FROM
IMPROPER SERVICE PROCEDURES. REPAIRS
SHOULD ONLY BE PERFORMED BY QUALIFIED
SERVICE PERSONNEL.
AVOID BREATHING THE REFRIGERANT AND
REFRIGERANT OIL VAPOR OR MIST. EXPOSURE
MAY IRRITATE THE EYES, NOSE, AND/OR THROAT.
WEAR EYE PROTECTION WHEN SERVICING THE
AIR CONDITIONING REFRIGERANT SYSTEM. SERI-
OUS EYE INJURY CAN RESULT FROM DIRECT
CONTACT WITH THE REFRIGERANT. IF EYE CON-
TACT OCCURS, SEEK MEDICAL ATTENTION IMME-
DIATELY.
DO NOT EXPOSE THE REFRIGERANT TO OPEN
FLAME. POISONOUS GAS IS CREATED WHEN
REFRIGERANT IS BURNED. AN ELECTRONIC LEAK
DETECTOR IS RECOMMENDED.
IF ACCIDENTAL SYSTEM DISCHARGE OCCURS,
VENTILATE THE WORK AREA BEFORE RESUMING
SERVICE. LARGE AMOUNTS OF REFRIGERANT
RELEASED IN A CLOSED WORK AREA WILL DIS-
PLACE THE OXYGEN AND CAUSE SUFFOCATION.
THE EVAPORATION RATE OF R-134a REFRIGER-
ANT AT AVERAGE TEMPERATURE AND ALTITUDE
IS EXTREMELY HIGH. AS A RESULT, ANYTHING
THAT COMES IN CONTACT WITH THE REFRIGER-
ANT WILL FREEZE. ALWAYS PROTECT THE SKIN
OR DELICATE OBJECTS FROM DIRECT CONTACT
WITH THE REFRIGERANT.
THE R-134a SERVICE EQUIPMENT OR THE VEHI-
CLE REFRIGERANT SYSTEM SHOULD NOT BE
PRESSURE TESTED OR LEAK TESTED WITH COM-
PRESSED AIR. SOME MIXTURES OF AIR AND
R-134a HAVE BEEN SHOWN TO BE COMBUSTIBLE
AT ELEVATED PRESSURES. THESE MIXTURES ARE
POTENTIALLY DANGEROUS, AND MAY RESULT IN
FIRE OR EXPLOSION CAUSING INJURY OR PROP-
ERTY DAMAGE.
24 - 52 PLUMBINGWJ

CAUTION
CAUTION
CAUTION: Liquid refrigerant is corrosive to metal
surfaces. Follow the operating instructions supplied
with the service equipment being used.
Never add R-12 to a refrigerant system designed to
use R-134a. Damage to the system will result.
R-12 refrigerant oil must not be mixed with R-134a
refrigerant oil. They are not compatible.
Do not use R-12 equipment or parts on the R-134a
system. Damage to the system will result.
Do not overcharge the refrigerant system. This will
cause excessive compressor head pressure and
can cause noise and system failure.
Recover the refrigerant before opening any fitting
or connection. Open the fittings with caution, even
after the system has been discharged. Never open
or loosen a connection before recovering the refrig-
erant.
The refrigerant system must always be evacuated
before charging.
Do not open the refrigerant system or uncap a
replacement component until you are ready to ser-
vice the system. This will prevent contamination in
the system.
Before disconnecting a component, clean the out-
side of the fittings thoroughly to prevent contami-
nation from entering the refrigerant system.
Immediately after disconnecting a component from
the refrigerant system, seal the open fittings with a
cap or plug.
Before connecting an open refrigerant fitting,
always install a new seal or gasket. Coat the fitting
and seal with clean refrigerant oil before connect-
ing.
Do not remove the sealing caps from a replacement
component until it is to be installed.
When installing a refrigerant line, avoid sharp
bends that may restrict refrigerant flow. Position the
refrigerant lines away from exhaust system compo-
nents or any sharp edges, which may damage the
line.
Tighten refrigerant fittings only to the specified
torque. The aluminum fittings used in the refriger-
ant system will not tolerate overtightening.
When disconnecting a refrigerant fitting, use a
wrench on both halves of the fitting. This will pre-
vent twisting of the refrigerant lines or tubes.
Refrigerant oil will absorb moisture from the atmo-
sphere if left uncapped. Do not open a container of
refrigerant oil until you are ready to use it. Replace
the cap on the oil container immediately after using.
Store refrigerant oil only in a clean, airtight, and
moisture-free container.Keep service tools and the work area clean. Con-
tamination of the refrigerant system through care-
less work habits must be avoided.REFRIGERANT HOSES/LINES/TUBES
PRECAUTIONS
Kinks or sharp bends in the refrigerant plumbing
will reduce the capacity of the entire system. High
pressures are produced in the system when it is oper-
ating. Extreme care must be exercised to make sure
that all refrigerant system connections are pressure
tight.
A good rule for the flexible hose refrigerant lines is
to keep the radius of all bends at least ten times the
diameter of the hose. Sharp bends will reduce the
flow of refrigerant. The flexible hose lines should be
routed so they are at least 80 millimeters (3 inches)
from the exhaust manifold. It is a good practice to
inspect all flexible refrigerant system hose lines at
least once a year to make sure they are in good con-
dition and properly routed.
There are two types of refrigerant fittings:
²All fittings with O-rings need to be coated with
refrigerant oil before installation. Use only O-rings
that are the correct size and approved for use with
R-134a refrigerant. Failure to do so may result in a
leak.
²Unified plumbing connections with gaskets can-
not be serviced with O-rings. The gaskets are not
reusable and new gaskets do not require lubrication
before installing.
Using the proper tools when making a refrigerant
plumbing connection is very important. Improper
tools or improper use of the tools can damage the
refrigerant fittings. Always use two wrenches when
loosening or tightening tube fittings. Use one wrench
to hold one side of the connection stationary, while
loosening or tightening the other side of the connec-
tion with a second wrench.
The refrigerant must be recovered completely from
the system before opening any fitting or connection.
Open the fittings with caution, even after the refrig-
erant has been recovered. If any pressure is noticed
as a fitting is loosened, tighten the fitting and
recover the refrigerant from the system again.
Do not discharge refrigerant into the atmosphere.
Use an R-134a refrigerant recovery/recycling device
that meets SAE Standard J2210.
The refrigerant system will remain chemically sta-
ble as long as pure, moisture-free R-134a refrigerant
and refrigerant oil is used. Dirt, moisture, or air can
upset this chemical stability. Operational troubles or
serious damage can occur if foreign material is
present in the refrigerant system.
When it is necessary to open the refrigerant sys-
tem, have everything needed to service the system
WJPLUMBING 24 - 53
PLUMBING (Continued)

(a) If the refrigerant system fails to reach the
specified vacuum, the system has a leak that must
be corrected. (Refer to 24 - HEATING & AIR CON-
DITIONING/PLUMBING - DIAGNOSIS AND
TESTING - REFRIGERANT SYSTEM LEAKS)
(b) If the refrigerant system maintains the spec-
ified vacuum for five minutes, restart the vacuum
pump, open the suction and discharge valves and
evacuate the system for an additional ten minutes.
(3) Close all of the valves, and turn off the charg-
ing station vacuum pump.
(4) The refrigerant system is now ready to be
charged with R-134a refrigerant. (Refer to 24 -
HEATING & AIR CONDITIONING/PLUMBING -
STANDARD PROCEDURE - REFRIGERANT SYS-
TEM CHARGE)
STANDARD PROCEDURE - REFRIGERANT
SYSTEM CHARGE
WARNING: REVIEW THE WARNINGS AND CAU-
TIONS IN THE FRONT OF THIS SECTION BEFORE
PERFORMING THE FOLLOWING OPERATION.
(Refer to 24 - HEATING & AIR CONDITIONING/
PLUMBING - WARNING) (Refer to 24 - HEATING &
AIR CONDITIONING/PLUMBING - CAUTION)
After the refrigerant system has been tested for
leaks and evacuated, a refrigerant charge can be
injected into the system. (Refer to 24 - HEATING &
AIR CONDITIONING/PLUMBING - SPECIFICA-
TIONS - CHARGE CAPACITY)
A R-134a refrigerant recovery/recycling/charging
station that meets SAE Standard J2210 must be
used to charge the refrigerant system with R-134a
refrigerant. Refer to the operating instructions sup-
plied by the equipment manufacturer for proper care
and use of this equipment.
PARTIAL CHARGE METHOD
WARNING: REVIEW THE WARNINGS AND CAU-
TIONS IN THE FRONT OF THIS SECTION BEFORE
PERFORMING THE FOLLOWING OPERATION.
(Refer to 24 - HEATING & AIR CONDITIONING/
PLUMBING - WARNING) (Refer to 24 - HEATING &
AIR CONDITIONING/PLUMBING - CAUTION)
The partial charge method is used to add a partial
charge to a refrigerant system that is low on refrig-
erant. To perform this procedure the evaporator inlet
and outlet tube temperatures are measured. The
temperature difference is measured with a tempera-
ture meter with one or two clamp-on thermocouple
probes. The difference between the evaporator inlet
and outlet tube temperatures will determine the
amount of refrigerant needed.Before adding a partial refrigerant charge, check
for refrigerant system leaks. (Refer to 24 - HEATING
& AIR CONDITIONING/PLUMBING - DIAGNOSIS
AND TESTING - REFRIGERANT SYSTEM LEAKS)
If a leak is found, make the necessary repairs before
attempting a full or partial refrigerant charge.
(1) Attach a manifold gauge set to the refrigerant
system service ports.
(2) Attach the two clamp-on thermocouple probes
to the inlet and outlet tubes of the evaporator coil.
²If a single thermocouple probe is used, attach
the probe to the evaporator inlet tube just before the
collar of the refrigerant line connector fitting. The
probe must make contact with the bottom surface of
the evaporator inlet tube.
²If dual thermocouple probes are used, attach
probe 1 to the evaporator inlet tube, and probe 2 to
the evaporator outlet tube. Attach both probes to the
evaporator tubes just before the collar of the refrig-
erant line connector fittings. The probes must make
contact with the bottom surfaces of the evaporator
inlet and outlet tubes.
(3) Open all of the windows or doors of the passen-
ger compartment.
(4) Set the A/C button on the A/C Heater controls
to the on position, the temperature control knob in
the full cool position, select Recirculation Mode, and
place the blower motor switch in the highest speed
position.
(5) Start the engine and hold the engine idle speed
at 1,000 rpm. Allow the engine to warm up to normal
operating temperature.
(6) The compressor clutch may cycle, depending
upon ambient temperature, humidity, and the refrig-
erant system charge level.
(7) Hold the engine idle speed at 1,000 rpm.
(8) Allow three to five minutes for the refrigerant
system to stabilize, then record the temperatures of
the evaporator inlet and outlet tubes.
²If a single probe is used, record the temperature
of the evaporator inlet tube. Then remove the probe
from the inlet tube and attach it to the evaporator
outlet tube just before the collar of the refrigerant
line connector fitting. The probe must make contact
with the bottom surface of the evaporator outlet tube.
Allow the thermocouple and meter time to stabilize,
then record the temperature of the evaporator outlet
tube. Subtract the inlet tube temperature reading
from the outlet tube temperature reading.
²If dual probes are used, record the temperatures
of both the evaporator inlet and outlet tubes. Then
subtract the inlet tube temperature reading from the
outlet tube temperature reading.
(9) If the measured temperature differential is
higher than 22É C to 26É C (40É F to 47É F), add 0.4
kilograms (14 ounces) of refrigerant.
24 - 56 PLUMBINGWJ
PLUMBING (Continued)

(10) Allow three to five minutes for the refrigerant
system to stabilize, then take a second set of thermo-
couple measurements. Record the temperature differ-
ence to determine if an additional charge is required.(11) Record the compressor discharge pressure. If
the reading is higher than the pressure shown in the
Compressor Discharge Pressure Chart, the system
could be overcharged. If the reading is equal to, or
lower, than the pressure shown in the chart, continue
with this procedure.
Compressor Discharge Pressure Chart
Ambient
Temperature16ÉC
(60ÉF)21ÉC
(70ÉF)27ÉC
(80ÉF)32ÉC
(90ÉF)38ÉC
(100ÉF)43ÉC
(110ÉF)
Compressor
Discharge
Pressure1378 kPa
(200 psi)1516 kPa
(220 psi)1723 kPa
(250psi)1930 kPa
(280 psi)2206 kPa
(320 psi)2413 kPa
(350 psi)
(12)EXAMPLE:The ambient temperature is 21É
C (70É F). The evaporator inlet tube temperature is
12É C (54É F) and the evaporator outlet tube temper-
ature is 10É C (50É F). Subtract the inlet tube tem-
perature from the outlet tube temperature. The
difference is -2É C (-4É F). With a -2É C (-4É F) tem-
perature differential at 21É C (70É F) ambient tem-
perature, the system is fully charged.
(13) Add enough refrigerant to bring the refriger-
ant system up to a full charge.
(14) Remove the jumper wire from the low pres-
sure cycling clutch switch wire harness connector
and plug the connector back into the switch.
SPECIFICATIONS
CHARGE CAPACITY
The R-134a refrigerant system charge capacity for
this vehicle is 0.765 kilograms (1.687 pounds/27
ounces).
A/C COMPRESSOR
DESCRIPTION
DESCRIPTION - A/C COMPRESSOR
The air conditioning system uses a Nippondenso
10PA17 ten cylinder, double-acting swash plate-type
compressor on all models. This compressor has a
fixed displacement of 170 cubic centimeters (10.374
cubic inches), and has both the suction and discharge
ports located on the cylinder head. A label identifying
the use of R-134a refrigerant is located on the com-
pressor.
DESCRIPTION - HIGH PRESSURE RELIEF
VALVE
A high pressure relief valve is located on the com-
pressor manifold, which is on the side of the com-
pressor. This mechanical valve is designed to vent
refrigerant from the system to protect against dam-
age to the compressor and other system components,
caused by condenser air flow restriction or an over-
charge of refrigerant.
OPERATION
OPERATION - A/C COMPRESSOR
The compressor is driven by the engine through an
electric clutch, drive pulley and belt arrangement.
The compressor is lubricated by refrigerant oil that is
circulated throughout the refrigerant system with the
refrigerant.
The compressor draws in low-pressure refrigerant
vapor from the evaporator through its suction port. It
then compresses the refrigerant into a high-pressure,
high-temperature refrigerant vapor, which is then
pumped to the condenser through the compressor dis-
charge port.
The compressor cannot be repaired. If faulty or
damaged, the entire compressor assembly must be
replaced. The compressor clutch, pulley, and coil, are
available for service.
OPERATION - HIGH PRESSURE RELIEF VALVE
The high pressure relief valve vents the system
when a discharge pressure of 3445 to 4135 kPa (500
to 600 psi) or above is reached. The valve closes
when a minimum discharge pressure of 2756 kPa
(400 psi) is reached.
WJPLUMBING 24 - 57
PLUMBING (Continued)

The high pressure relief valve vents only enough
refrigerant to reduce the system pressure, and then
re-seats itself. The majority of the refrigerant is con-
served in the system. If the valve vents refrigerant, it
does not mean that the valve is faulty.
The high pressure relief valve is a factory-cali-
brated unit. The valve cannot be adjusted or
repaired, and must not be removed or otherwise dis-
turbed. The valve is only serviced as a part of the
compressor assembly.
DIAGNOSIS AND TESTING - COMPRESSOR
NOISE
When investigating an air conditioning related
noise, you must first know the conditions under
which the noise occurs. These conditions include:
weather, vehicle speed, transmission in gear or neu-
tral, engine speed, engine temperature, and any
other special conditions. Noises that develop during
air conditioning operation can often be misleading.
For example: What sounds like a failed front bearing
or connecting rod, may be caused by loose bolts, nuts,
mounting brackets, or a loose compressor clutch
assembly.
Drive belts are speed sensitive. At different engine
speeds and depending upon belt tension, belts can
develop noises that are mistaken for a compressor
noise. Improper belt tension can cause a misleading
noise when the compressor clutch is engaged, which
may not occur when the compressor clutch is disen-
gaged. Check the serpentine drive belt condition and
tension as described in Cooling before beginning this
procedure.
(1) Select a quiet area for testing. Duplicate the
complaint conditions as much as possible. Switch the
compressor on and off several times to clearly iden-
tify the compressor noise. Listen to the compressor
while the clutch is engaged and disengaged. Probe
the compressor with an engine stethoscope or a long
screwdriver with the handle held to your ear to bet-
ter localize the source of the noise.
(2) Loosen all of the compressor mounting hard-
ware and retighten. Tighten the compressor clutch
mounting nut. Be certain that the clutch coil is
mounted securely to the compressor, and that the
clutch plate and pulley are properly aligned and have
the correct air gap. (Refer to 24 - HEATING & AIR
CONDITIONING/CONTROLS/A/C COMPRESSOR
CLUTCH - INSTALLATION)
(3) To duplicate a high-ambient temperature condi-
tion (high head pressure), restrict the air flow
through the condenser. Install a manifold gauge set
to be certain that the discharge pressure does not
exceed 2760 kPa (400 psi).
(4) Check the refrigerant system plumbing for
incorrect routing, rubbing or interference, which cancause unusual noises. Also check the refrigerant lines
for kinks or sharp bends that will restrict refrigerant
flow, which can cause noises. (Refer to 24 - HEAT-
ING & AIR CONDITIONING/PLUMBING - CAU-
TION - REFRIGERANT HOSES/LINES/TUBES
PRECAUTIONS)
(5) If the noise is from opening and closing of the
high pressure relief valve, reclaim, evacuate, and
recharge the refrigerant system. (Refer to 24 - HEAT-
ING & AIR CONDITIONING/PLUMBING - STAN-
DARD PROCEDURE - REFRIGERANT RECOVERY)
(Refer to 24 - HEATING & AIR CONDITIONING/
PLUMBING - STANDARD PROCEDURE - REFRIG-
ERANT SYSTEM EVACUATE) (Refer to 24 -
HEATING & AIR CONDITIONING/PLUMBING -
STANDARD PROCEDURE - REFRIGERANT SYS-
TEM CHARGE)If the high pressure relief valve still
does not seat properly, replace the a/c compressor.
(Refer to 24 - HEATING & AIR CONDITIONING/
PLUMBING/A/C COMPRESSOR - REMOVAL)
(6) If the noise is from liquid slugging on the suc-
tion line, check the refrigerant oil level and the
refrigerant system charge. (Refer to 24 - HEATING
& AIR CONDITIONING/PLUMBING/REFRIGER-
ANT OIL - STANDARD PROCEDURE) (Refer to 24 -
HEATING & AIR CONDITIONING/PLUMBING -
SPECIFICATIONS - CHARGE CAPACITY).
(7) If the noise continues, replace the compressor
and repeat Step 1.
REMOVAL
REMOVAL
The compressor may be removed and repositioned
without disconnecting the refrigerant lines or dis-
charging the refrigerant system. Discharging is not
necessary if servicing the compressor clutch or clutch
coil, the engine, the cylinder head, or the generator.
WARNING: REVIEW THE WARNINGS AND CAU-
TIONS IN THE FRONT OF THIS SECTION BEFORE
PERFORMING THE FOLLOWING OPERATION.
(Refer to 24 - HEATING & AIR CONDITIONING/
PLUMBING - WARNING) (Refer to 24 - HEATING &
AIR CONDITIONING/PLUMBING - CAUTION)
(1) Recover the refrigerant from the system. (Refer
to 24 - HEATING & AIR CONDITIONING/PLUMB-
ING - STANDARD PROCEDURE - REFRIGERANT
RECOVERY)
(2) Disconnect and isolate the battery negative
cable.
(3) Remove the serpentine drive belt. Refer to
Cooling for the procedures.
(4) Unplug the compressor clutch coil wire harness
connector.
24 - 58 PLUMBINGWJ
A/C COMPRESSOR (Continued)

INSTALLATION
INSTALLATION
WARNING: REVIEW THE WARNINGS AND CAU-
TIONS IN THE FRONT OF THIS SECTION BEFORE
PERFORMING THE FOLLOWING OPERATION.
(Refer to 24 - HEATING & AIR CONDITIONING/
PLUMBING - WARNING) (Refer to 24 - HEATING &
AIR CONDITIONING/PLUMBING - CAUTION)
Any kinks or sharp bends in the refrigerant plumb-
ing will reduce the capacity of the entire air condi-
tioning system. Kinks and sharp bends reduce the
flow of refrigerant in the system. A good rule for the
flexible hose refrigerant lines is to keep the radius of
all bends at least ten times the diameter of the hose.
In addition, the flexible hose refrigerant lines should
be routed so they are at least 80 millimeters (3
inches) from the exhaust manifold.
High pressures are produced in the refrigerant sys-
tem when the air conditioning compressor is operat-
ing. Extreme care must be exercised to make sure
that each of the refrigerant system connections is
pressure-tight and leak free. It is a good practice to
inspect all flexible hose refrigerant lines at least once
a year to make sure they are in good condition and
properly routed.
NOTE: If a replacement compressor is being
installed, be certain to check the refrigerant oil
level. (Refer to 24 - HEATING & AIR CONDITIONING/
PLUMBING/REFRIGERANT OIL - STANDARD PRO-
CEDURE) Use only refrigerant oil of the type
recommended for the compressor in the vehicle.
(Refer to 24 - HEATING & AIR CONDITIONING/
PLUMBING/REFRIGERANT OIL - DESCRIPTION)
(1) Install the compressor. Tighten the 4.0L
mounting bolts fastening the compressor to the block
to 45-65 N´m (35-50 ft. lbs.). Tighten the mounting
bolts holding the rear brace to the compressor and
block to 40-55 N´m (30-40 ft. lbs.). Tighten the 4.7L
compressor front mounting screws to 45-65 N´m
(35-50 ft. lbs.), and the rear mounting screws to
35-45 N´m (25-35 ft. lbs.).
(2) Remove the tape or plugs from all of the
opened refrigerant line fittings. Install the suction
line and discharge line fittings to the manifold on the
compressor. Tighten the mounting bolts to 25.4 N´m
(225 in. lbs.).
(3) Install the serpentine drive belt. Refer to Cool-
ing for the procedures.
(4) Plug in the compressor clutch coil wire harness
connector.
(5) Connect the battery negative cable.(6) Evacuate the refrigerant system. (Refer to 24 -
HEATING & AIR CONDITIONING/PLUMBING -
STANDARD PROCEDURE - REFRIGERANT SYS-
TEM EVACUATE)
(7) Charge the refrigerant system. (Refer to 24 -
HEATING & AIR CONDITIONING/PLUMBING -
STANDARD PROCEDURE - REFRIGERANT SYS-
TEM CHARGE)
INSTALLATION - 2.7L TURBO DIESEL
CAUTION: Check the oil level before installing the
new compressor. (Refer to 24 - HEATING & AIR
CONDITIONING/PLUMBING/REFRIGERANT OIL -
STANDARD PROCEDURE)
WARNING: REVIEW THE WARNINGS AND CAU-
TIONS IN THE FRONT OF THIS SECTION BEFORE
PERFORMING THE FOLLOWING OPERATION.
(Refer to 24 - HEATING & AIR CONDITIONING/
PLUMBING - WARNING) (Refer to 24 - HEATING &
AIR CONDITIONING/PLUMBING - CAUTION)
Any kinks or sharp bends in the refrigerant plumb-
ing will reduce the capacity of the entire air condi-
tioning system. Kinks and sharp bends reduce the
flow of refrigerant in the system. A good rule for the
flexible hose refrigerant lines is to keep the radius of
all bends at least ten times the diameter of the hose.
In addition, the flexible hose refrigerant lines should
be routed so they are at least 80 millimeters (3
inches) from the exhaust manifold.
High pressures are produced in the refrigerant sys-
tem when the air conditioning compressor is operat-
ing. Extreme care must be exercised to make sure
that each of the refrigerant system connections is
pressure-tight and leak free. It is a good practice to
inspect all flexible hose refrigerant lines at least once
a year to make sure they are in good condition and
properly routed.
(1) Lift the compressor into position and install
the (4) mounting bolts. Torque the bolts to 41 N´m
(30 ft. lbs.).
(2) Connect the compressor clutch electrical con-
nector.
(3) Install both refrigerant lines on the compressor.
Make certain the sealing 0-rings are free of tears and
well lubricated with R-134a refrigerant oil. Torque
the line retaining bolts to 22 N´m (200 in. lbs.).
(4) Install the front splash shield (if equipped).
(5) Lower the vehicle from the hoist.
(6) Install the accessory drive belt on the compres-
sor clutch. Refer to Cooling for the procedure.
(7) Evacuate the refrigerant system. (Refer to 24 -
HEATING & AIR CONDITIONING/PLUMBING -
WJPLUMBING 24 - 61
A/C COMPRESSOR (Continued)

(11) Remove the bolts that secure the upper con-
denser and transmission cooler.
(12) Carefully lift the condenser out of the vehicle.
INSTALLATION
WARNING: REVIEW THE WARNINGS AND CAU-
TIONS IN THE FRONT OF THIS SECTION BEFORE
PERFORMING THE FOLLOWING OPERATION.
(Refer to 24 - HEATING & AIR CONDITIONING/
PLUMBING - WARNING) (Refer to 24 - HEATING &
AIR CONDITIONING/PLUMBING - CAUTION)
Any kinks or sharp bends in the refrigerant plumb-
ing will reduce the capacity of the entire air condi-
tioning system. Kinks and sharp bends reduce the
flow of refrigerant in the system. A good rule for the
flexible hose refrigerant lines is to keep the radius of
all bends at least ten times the diameter of the hose.
In addition, the flexible hose refrigerant lines should
be routed so they are at least 80 millimeters (3
inches) from the exhaust manifold.
High pressures are produced in the refrigerant sys-
tem when the air conditioning compressor is operat-
ing. Extreme care must be exercised to make sure
that each of the refrigerant system connections is
pressure-tight and leak free. It is a good practice to
inspect all flexible hose refrigerant lines at least once
a year to make sure they are in good condition and
properly routed.
CAUTION: Before removing the condenser, note the
location of each of the radiator and condenser air
seals. These seals are used to direct air through the
condenser and radiator. The air seals must be rein-
stalled in their proper locations in order for the air
conditioning and engine cooling systems to per-
form as designed.
(1) Carefully position the condenser in the vehicle.
(2) Install the bolts that secure the upper con-
denser and transmission cooler.
(3) Remove the tape or plugs from the refrigerant
line fittings on the condenser inlet and the discharge
line. Connect the discharge line to the condenser
inlet. Tighten the retaining nut to 28 N´m (250 in.
lbs.).
(4) Remove the tape or plugs from the refrigerant
line fittings on the condenser outlet and the liquid
line. Connect the liquid line to the condenser outlet.
Tighten the retaining nut to 28 N´m (250 in. lbs.).
(5) Install the headlamp mounting module and
front fascia. Refer to Body for the procedure.
(6) Install the engine air filter inlet duct.
(7) Install the bolts that secure the radiator to the
upper crossmember.(8) Install the nuts that secure the hood latch and
brace to the upper crossmember.
(9) Install the headlamps in their mounts.
(10) Install the screws attaching the grille and
headlamp mounting module to the upper crossmem-
ber of the vehicle. Refer to Body for this and further
steps in the procedure.
(11) Evacuate and Recharge the refrigerant sys-
tem. (Refer to 24 - HEATING & AIR CONDITION-
ING/PLUMBING - STANDARD PROCEDURE -
REFRIGERANT SYSTEM EVACUATE) (Refer to 24 -
HEATING & AIR CONDITIONING/PLUMBING -
STANDARD PROCEDURE - REFRIGERANT SYS-
TEM CHARGE)
(12) Connect the battery negative cable.
NOTE: If the condenser is replaced, add 30 millili-
ters (1 fluid ounce) of refrigerant oil to the refriger-
ant system. Use only refrigerant oil of the type
recommended for the compressor in the vehicle.
(Refer to 24 - HEATING & AIR CONDITIONING/
PLUMBING/REFRIGERANT OIL - DESCRIPTION)
A/C DISCHARGE LINE
REMOVAL
REMOVAL - 2.7L TURBO DIESEL
WARNING: REVIEW THE WARNINGS AND CAU-
TIONS IN THE FRONT OF THIS SECTION BEFORE
PERFORMING THE FOLLOWING OPERATION.
(Refer to 24 - HEATING & AIR CONDITIONING/
PLUMBING - WARNING) (Refer to 24 - HEATING &
AIR CONDITIONING/PLUMBING - CAUTION)
(1) Disconnect and isolate the negative battery
cable.
(2) Recover the refrigerant system. (Refer to 24 -
HEATING & AIR CONDITIONING/PLUMBING -
STANDARD PROCEDURE - REFRIGERANT
RECOVERY)
(3) Remove both headlamps from the vehicle. Refer
to Lamps/Lighting for the procedure.
(4) Remove the a/c high pressure transducer(Refer
to 24 - HEATING & AIR CONDITIONING/CON-
TROLS/A/C PRESSURE TRANSDUCER - REMOV-
AL).
(5) Remove the front fascia from the vehicle. Refer
to Front Fascia for the procedure (Fig. 7).
(6) Remove the refrigerant line retaining fastener
from the condenser inlet fitting. Remove the line and
cap the condenser inlet tube to prevent contamina-
tion of the system.
WJPLUMBING 24 - 63
A/C CONDENSER (Continued)