2004 DODGE TOWN AND COUNTRY low oil pressure

SERVICE PORT VALVE CORE
DESCRIPTION.........................94
REMOVAL.............................94
INSTALLATION.........................94SUCTION LINE
REMOVAL.............................94
INSTALLATION.........................95
PLUMBING - FRONT
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 an exhaust manifold.
OPERATION- REFRIGERANT LINES
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 are coupled with
other components of the HVAC system with either
O-rings or dual plane seals.
The refrigerant lines and hoses cannot be repaired
and, if faulty or damaged, they must be replaced.
WARNING
ENGINE COOLING SYSTEM
WARNING: THE ENGINE COOLING SYSTEM IS
DESIGNED TO DEVELOP INTERNAL PRESSURES
OF 97 TO 123 KILOPASCALS (14 TO 18 POUNDS
PER SQUARE INCH). DO NOT REMOVE OR
LOOSEN THE COOLANT PRESSURE CAP, CYLIN-
DER BLOCK DRAIN PLUGS, RADIATOR DRAIN,
RADIATOR HOSES, HEATER HOSES, OR HOSE
CLAMPS WHILE THE ENGINE COOLING SYSTEM ISHOT AND UNDER PRESSURE. FAILURE TO
OBSERVE THIS WARNING CAN RESULT IN SERI-
OUS BURNS FROM THE HEATED ENGINE COOL-
ANT. ALLOW THE VEHICLE TO COOL FOR A
MINIMUM OF 15 MINUTES BEFORE OPENING THE
COOLING SYSTEM FOR SERVICE.
A/C SYSTEM
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.
RSPLUMBING - FRONT24-65

CAUTION
A/C SYSTEM
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 and do not use R-12 equipment or parts
on the R-134a system. Damage to the system will
result.
R-12 refrigerant oil must not be mixed with R-134a
refrigerant oil. They are not compatible and damage
to the system will result.
Do not overcharge the refrigerant system. Over-
charging 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.
If equipped, do not remove the secondary retention
clip from any spring-lock coupler connection while
the refrigerant system is under pressure. Recover
the refrigerant before removing the secondary
retention clip. Open the fittings with caution, even
after the system has been discharged. Never open
or loosen a connection before recovering the refrig-
erant.
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 outside of the fittings thoroughly to pre-
vent contamination from entering the refrigerant
system. Immediately after disconnecting a compo-
nent from the refrigerant system, seal the open fit-
tings with a cap or plug.
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 must be
avoided.
CAUTION: The use of A/C system sealers may
result in damage to A/C refrigerant recovery/evacu-
ation/recharging equipment and/or A/C systems.
Many federal, state/provincial and local regulations
prohibit the recharge of A/C systems with known
leaks. DaimlerChrysler recommends the detection
of A/C system leaks through the use of approvedleak detectors and fluorescent leak detection dyes.
Vehicles found with A/C system sealers should be
treated as contaminated and replacement of the
entire A/C refrigerant system is recommended. A/C
systems found to be contaminated with A/C system
sealers, A/C stop-leak products or seal conditioners
voids the warranty for the A/C system.
DIAGNOSIS AND TESTING
DIAGNOSIS AND TESTING - REFRIGERANT
SYSTEM LEAKS
WARNING: R-134a SERVICE EQUIPMENT OR VEHI-
CLE A/C SYSTEM SHOULD NOT BE PRESSURE
TESTED OR LEAK TESTED WITH COMPRESSED
AIR. MIXTURE OF AIR and R-134a CAN BE COM-
BUSTIBLE AT ELEVATED PRESSURES. THESE MIX-
TURES ARE POTENTIALLY DANGEROUS AND MAY
RESULT IN FIRE OR EXPLOSION CAUSING INJURY
OR PROPERTY DAMAGE.
AVOID BREATHING A/C REFRIGERANT AND LUBRI-
CANT VAPOR OR MIST. EXPOSURE MAY IRRITATE
EYES, NOSE AND THROAT. USE ONLY APPROVED
SERVICE EQUIPMENT MEETING SAE REQUIRE-
MENTS TO DISCHARGE R-134a SYSTEM. IF ACCI-
DENTAL SYSTEM DISCHARGE OCCURS,
VENTILATE WORK AREA BEFORE RESUMING SER-
VICE.
If the A/C system is not cooling properly, determine
if the refrigerant system is fully charged with R-134a
(Refer to 24 - HEATING & AIR CONDITIONING/
PLUMBING - FRONT/REFRIGERANT - DIAGNO-
SIS AND TESTING - REFRIGERANT SYSTEM
CHARGE LEVEL). If while performing this test A/C
liquid line pressure is less than 345 kPa (50 psi) pro-
ceed to System Empty procedure. If liquid line pres-
sure is greater than 345 kPa (50 psi) proceed to
System Low procedure. If the refrigerant system is
empty or low in refrigerant charge, a leak at any line
fitting or component seal is likely. A review of the fit-
tings, lines and components for oily residue is an
indication of the leak location.
To detect a leak in the refrigerant system, perform
one of the following procedures as indicated by the
results of the refrigerant system charge level test.
SYSTEM EMPTY
(1) Evacuate the refrigerant system to the lowest
degree of vacuum possible (approx. 28 in Hg.) (Refer
to 24 - HEATING & AIR CONDITIONING/PLUMB-
ING - FRONT/REFRIGERANT - STANDARD PRO-
CEDURE - REFRIGERANT SYSTEM EVACUATE).
Determine if the system holds a vacuum for 15 min-
utes. If vacuum is held, a leak is probably not
24 - 66 PLUMBING - FRONTRS
PLUMBING - FRONT (Continued)

present. If system will not maintain vacuum level,
proceed with this procedure.
(2) Prepare a 0.284 Kg. (10 oz.) refrigerant charge
to be injected into the system.
(3) Connect and dispense 0.284 Kg. (10 oz.) of
refrigerant into the evacuated refrigerant system
(Refer to 24 - HEATING & AIR CONDITIONING/
PLUMBING - FRONT/REFRIGERANT - STANDARD
PROCEDURE - REFRIGERANT SYSTEM
CHARGE).
(4) Proceed to the SYSTEM LOW procedures.
SYSTEM LOW
(1) Position the vehicle in a wind-free work area.
This will aid in detecting small leaks.
(2) Bring the refrigerant system up to operating
temperature and pressure. This is done by allowing
the engine to run for five minutes with the system
set to the following:
²Transaxle in Park
²Engine idling
²Rear A/C Off (if equipped)
²A/C controls set to 100 percent outside air
²Blower switch in the highest speed position
²A/C in the ON position
²Front windows open
CAUTION: A leak detector designed for R-12 refrig-
erant (only) will not detect leaks in a R-134a refrig-
erant system.
(3) Shut off the vehicle and wait 2 to 7 minutes.
Then use an Electronic Leak Detector that is
designed to detect R-134a type refrigerant and search
for leaks. Fittings, lines, or components that appear
to be oily usually indicates a refrigerant leak. To
inspect the evaporator core for leaks, insert the leak
detector probe into the drain tube opening or a heat
duct. A R-134a dye is available to aid in leak detec-
tion, use only DaimlerChrysler approved refrigerant
dye.
DIAGNOSIS AND TESTING - SYSTEM CHARGE
LEVEL TEST - GASOLINE ENGINES
WARNING: REFER TO THE APPLICABLE WARN-
INGS AND CAUTIONS FOR THIS SYSTEM BEFORE
PERFORMING THE FOLLOWING OPERATION (Refer
to 24 - HEATING & AIR CONDITIONING/PLUMBING -
FRONT - WARNING - A/C PLUMBING) and (Refer to
24 - HEATING & AIR CONDITIONING/PLUMBING -
FRONT - CAUTION - A/C PLUMBING).
NOTE: The proper amount of R-134a refrigerant for
the refrigerant system in this model is:²Single or Dual Zone (Front Unit Only) - 0.96
kilograms (2.13 pounds or 34 ounces)
²Three Zone (Front and Rear Units) - 1.31 kilo-
grams (2.88 pounds or 46 ounces)
The procedure that follows should be used to deter-
mine whether the refrigerant system contains the
proper refrigerant charge. Symptoms of an improper
refrigerant charge (low) include: poor air conditioner
performance, fog emitted from the air conditioner
outlets, a hissing sound from the expansion valve/
evaporator area. There are two different methods
with which the refrigerant charge level may be
tested:
1. Using a DRBIIItscan tool, a thermocouple and
the Charge Determination Chart (Fig. 1). Refer to
the appropriate diagnostic information.
2. Using a manifold gauge set, a thermocouple and
the Charge Determination Chart (Fig. 1).
A temperature probe is required to measure liquid
line temperature. The clamp-on, Type K thermocou-
ple temperature probe used in this procedure is
available through the DaimlerChrysler Professional
Service Equipment (PSE) program. This probe (PSE
#66-324-0014 or #80PK-1A) is compatible with tem-
perature-measuring instruments that accept Type K
thermocouples, and have a miniature connector
input. Other temperature probes are available
through aftermarket sources; however, all references
in this procedure will reflect the use of the probe
made available through the PSE program.
In order to use the temperature probe, a digital
thermometer will also be required. If a digital ther-
mometer is not available, an adapter is available
through the PSE program that will convert any stan-
dard digital multimeter into a digital thermometer.
This adapter is designed to accept any standard Type
K thermocouple. If a digital multimeter is not avail-
able, this tool is also available through the PSE pro-
gram.
NOTE: When connecting the service equipment
couplings to the refrigerant system service ports,
be certain that the valve of each coupling is fully
closed. This will reduce the amount of effort
required to make the connection.
(1) Remove the caps from the refrigerant system
service ports and attach a manifold gauge set or a
R-134a refrigerant recovery/recycling/charging sta-
tion that meets SAE Standard J2210 to the refriger-
ant system.
(2) Attach a clamp-on thermocouple to the liquid
line. The thermocouple must be placed as close to the
A/C pressure transducer as possible to accurately
observe liquid line temperature.
(3) Bring the refrigerant system up to operating
temperature and pressure. This is done by allowing
RSPLUMBING - FRONT24-67
PLUMBING - FRONT (Continued)

tion that meets SAE Standard J2210 to the refriger-
ant system.
(2) Attach a clamp-on thermocouple to the liquid
line. The thermocouple must be placed as close to the
A/C pressure transducer as possible to accurately
observe liquid line temperature.
(3) Bring the refrigerant system up to operating
temperature and pressure. This is done by allowing
the engine to run at idle under the following condi-
tions for five minutes.
(a) Front windows are open.
(b) Transaxle in Park.
(c) Front heater-A/C controls set to outside air,
full cool, panel mode, blower high, and compressor
engaged.
(d) If the vehicle is so equipped, the rear heater-
A/C controls must be set to full cool and blower
high.
(4) Raise the liquid line (discharge) pressure to
about 1793 kPa (260 psi) by placing a piece of card-
board over part of the front side of the condenser. To
place the cardboard properly, remove the upper radi-
ator sight shield from the front fascia. Cover only
enough of the condenser to raise and maintain the
liquid line pressure at the specified level.
(5) Observe the liquid line (discharge) pressure
and liquid line temperature. Using the Charge Deter-
mination Chart (Fig. 2), determine whether the
refrigerant system is operating within the Proper
Charge Range.
(a) If the refrigerant system is operating in the
Undercharged area of the chart, add 0.057 kilo-
gram (0.125 pound or 2 ounces) of refrigerant to
the system.
(b) If the refrigerant system is operating in the
Overcharged area of the chart, reclaim 0.057 kilo-
gram (0.125 pound or 2 ounces) of refrigerant from
the system.
(6) Recheck the system charge level following each
refrigerant adjustment. Continue this process until
the system readings are in the Proper Charge Range
area on the Charge Determination Chart (Fig. 2).
STANDARD PROCEDURE
STANDARD PROCEDURE - HANDLING TUBING
AND FITTINGS
CAUTION: The system must be completely empty
before opening any fitting or connection in the
refrigeration system. Open fittings with caution
even after the system has been emptied. If any
pressure is noticed as a fitting is loosened,
retighten fitting and evacuate the system again.
A good rule for the flexible hose lines is to keep theradius of all bends at least 10 times the diameter of
the hose. Sharper bends will reduce the flow of
refrigerant. The flexible hose lines should be routed
so they are at least 3 inches (80 mm) from the
exhaust manifold. Inspect all flexible hose lines to
make sure they are in good condition and properly
routed.
The use of correct wrenches when making connec-
tions is very important. Improper wrenches or
improper use of wrenches can damage the fittings.
The internal parts of the A/C system will remain sta-
ble as long as moisture-free refrigerant and refrig-
erant oil is used. Abnormal amounts of dirt,
moisture or air can upset the chemical stability.
This may cause operational troubles or even seri-
ous damage if present in more than very small
quantities. Before disconnecting a component,
clean the outside of the fittings thoroughly to pre-
vent contamination from entering the refrigerant
system.
When opening a refrigeration system, have every-
thing you will need to repair the system ready. This
will minimize the amount of time the system must
be opened. Cap or plug all lines and fittings as
soon as they are opened. This will help prevent the
entrance of dirt and moisture. All new lines and
components should be capped or sealed until they
are ready to be used. Before connecting a compo-
nent, clean the outside of the fittings thoroughly to
prevent contamination from entering the refrigerant
system.
All tools, including the refrigerant dispensing mani-
fold, the manifold gauge set, and test hoses should
be kept clean and dry.
Kinks in the refrigerant tubing or sharp bends in
the refrigerant hose lines will greatly reduce the
capacity of the entire system. High pressures are pro-
duced in the system when it is operating. Extreme
care must be exercised to make sure that all connec-
tions are pressure tight. Dirt and moisture can enter
the system when it is opened for repair or replace-
ment of lines or components. The refrigerant oil will
absorb moisture readily out of the air. This moisture
will convert into acids within a closed system.
STANDARD PROCEDURE - REFRIGERANT
SYSTEM SERVICE EQUIPMENT
WARNING: EYE PROTECTION MUST BE WORN
WHEN SERVICING AN AIR CONDITIONING REFRIG-
ERANT SYSTEM. TURN OFF (ROTATE CLOCKWISE)
ALL VALVES ON THE EQUIPMENT BEING USED
BEFORE CONNECTING TO, OR DISCONNECTING
FROM THE REFRIGERANT SYSTEM. FAILURE TO
OBSERVE THESE WARNINGS MAY RESULT IN PER-
SONAL INJURY.
24 - 70 PLUMBING - FRONTRS
PLUMBING - FRONT (Continued)

A R-134a refrigerant recovery/recycling/charging
station that meets SAE Standard J2210 must be
used to recover the refrigerant from an R-134a refrig-
erant system. Refer to the operating instructions sup-
plied by the equipment manufacturer for the proper
care and use of this equipment.
STANDARD PROCEDURE - REFRIGERANT
SYSTEM EVACUATE
NOTE: Special effort must be used to prevent mois-
ture from entering the A/C system oil. Moisture in
the oil is very difficult to remove and will cause a
reliability problem with the compressor.
If a compressor designed to use R-134a refrigerant
is left open to the atmosphere for an extended period
of time. It is recommended that the refrigerant oil be
drained and replaced with new oil or a new compres-
sor be used. This will eliminate the possibility of con-
taminating the refrigerant system.
If the refrigerant system has been open to the
atmosphere, it must be evacuated before the system
can be filled. Moisture and air mixed with the refrig-
erant will raise the compressor head pressure above
acceptable operating levels. This will reduce the per-
formance of the air conditioner and damage the com-
pressor. Moisture will boil at near room temperature
when exposed to vacuum. A R-134a refrigerant recov-
ery/recycling/charging station that meets SAE Stan-
dard J2210 must be used to evacuate the refrigerant
system. See the operating instructions supplied by
the equipment manufacturer for proper care and use
of this equipment. To evacuate the refrigerant sys-
tem, use the following procedure:
NOTE: When connecting the service equipment
couplings to the refrigerant system service ports,
be certain that the valve of each coupling is fully
closed. This will reduce the amount of effort
required to make the connection.
(1) Recover the refrigerant system (Refer to 24 -
HEATING & AIR CONDITIONING/PLUMBING -
STANDARD PROCEDURE).
(2) Connect a suitable charging station, refrigerant
recovery machine or a manifold gauge set with vac-
uum pump and refrigerant recovery equipment.
(3) Open the suction and discharge valves and
start the vacuum pump. The vacuum pump should
run a minimum of 45 minutes prior to charge to
eliminate all moisture in system. When the suction
gauge reads -88 kPa (-26 in. Hg) vacuum or greater
for 30 minutes, close all valves and turn off vacuum
pump. If the system fails to reach specified vacuum,
the refrigerant system likely has a leak that must be
corrected. If the refrigerant system maintains speci-fied vacuum for at least 30 minutes, start the vac-
uum pump, open the suction and discharge valves.
Then allow the system to evacuate an additional 10
minutes.
(4) Close all valves. Turn off and disconnect the
vacuum pump.
(5) Charge the refrigerant system (Refer to 24 -
HEATING & AIR CONDITIONING/PLUMBING -
STANDARD PROCEDURE).STANDARD PROCEDURE - REFRIGERANT
SYSTEM CHARGE
WARNING: REFER TO THE APPLICABLE WARN-
INGS AND CAUTIONS FOR THIS SYSTEM BEFORE
PERFORMING THE FOLLOWING OPERATION (Refer
to 24 - HEATING & AIR CONDITIONING/PLUMBING -
FRONT - WARNING - A/C PLUMBING) and (Refer to
24 - HEATING & AIR CONDITIONING/PLUMBING -
FRONT - CAUTION - A/C PLUMBING).
After all refrigerant system leaks have been
repaired and the refrigerant system has been evacu-
ated, a refrigerant charge can be injected into the
system. For the proper amount of the refrigerant
charge, refer to REFRIGERANT CHARGE CAPAC-
ITY. 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. See the operating instructions supplied
by the equipment manufacturer for proper care and
use of this equipment.
REFRIGERANT CHARGE CAPACITY
The R-134a refrigerant system charge capacity for
this vehicle is:
²Single or Dual Zone (Front Unit Only - with
2.5L Turbo Diesel)0.79 kilograms (1.75 pounds or
28 ounces)
²Single or Dual Zone (Front Unit Only)- 0.88
kilograms (1.94 pounds or 31 ounces)
²Three Zone (Front and Rear Units)- 1.21
kilograms (2.69 pounds or 43 ounces)
NOTE: Always refer to the underhood HVAC Speci-
fication Tag for the latest fill specification for the
vehicle being serviced.
24 - 72 PLUMBING - FRONTRS
PLUMBING - FRONT (Continued)

CHARGING PROCEDURE
CAUTION: A small amount of refrigerant oil is
removed from the A/C system each time the refrig-
erant system is recovered and evacuated. Before
charging the A/C system, you MUST replenish any
oil lost during the recovery process. Refer the
equipment manufacturer instructions for more infor-
mation.
(1) Evacuate the refrigerant system. (Refer to 24 -
HEATING & AIR CONDITIONING/PLUMBING -
FRONT/REFRIGERANT - STANDARD PROCE-
DURE - REFRIGERANT SYSTEM EVACUATE).
(2) A manifold gauge set and a R-134a refrigerant
recovery/recycling/charging station that meets SAE
Standard J2210 should still be connected to the
refrigerant system.
(3) Measure the proper amount of refrigerant and
heat it to 52É C (125É F) with the charging station.
See the operating instructions supplied by the equip-
ment manufacturer for proper use of this equipment.
(4) Open both the suction and discharge valves,
then open the charge valve to allow the heated
refrigerant to flow into the system.
(5) When the transfer of refrigerant has stopped,
close both the suction and discharge valves.
(6) If all of the refrigerant charge did not transfer
from the dispensing device, open all of the windows
in the vehicle and set the heater-air conditioner con-
trols so that the compressor is engaged and the
blower motor is operating at its lowest speed setting.
Run the engine at a steady high idle (about 1400
rpm). If the compressor will not engage, test the com-
pressor clutch control circuit and repair as required.
(7) Open the suction valve to allow the remaining
refrigerant to transfer to the refrigerant system.
WARNING: TAKE CARE NOT TO OPEN THE DIS-
CHARGE (HIGH PRESSURE) VALVE AT THIS TIME.
(8) Close the suction valve and test the system
performance. (Refer to 24 - HEATING & AIR CON-
DITIONING - STANDARD PROCEDURE - A/C PER-
FORMANCE TEST).
(9) Disconnect the charging station and manifold
gauge set from the refrigerant system service ports.
(10) Reinstall the caps onto the refrigerant system
service ports.
(11) Run the HVAC Control Cooldown test to ver-
ify proper operation(Refer to 24 - HEATING & AIR
CONDITIONING - DIAGNOSIS AND TESTING).A/C COMPRESSOR
DESCRIPTION
DESCRIPTION - A/C COMPRESSOR
Vehicles equipped with the 2.5L diesel, 3.3L and
3.8L gasoline engines use the Denso 10S20 A/C com-
pressor. Vehicles equipped with the 2.4L gasoline
engine use the Denso 10S17 A/C compressor. Both
A/C compressors include an integral high pressure
relief valve. The A/C compressor is secured to a
mounting bracket on the 2.4L gasoline engine and
directly to the cylinder block on the 2.5L diesel, 3.3L
and 3.8L gasoline engines.
DESCRIPTION - HIGH PRESSURE RELIEF
VALVE
A high pressure relief valve is located on the rear
of the A/C compressor. This mechanical valve is
designed to vent refrigerant from the A/C system to
protect against damage to the compressor and other
system components, caused by condenser air flow
restriction or an overcharge of refrigerant.
OPERATION
OPERATION - A/C COMPRESSOR
The A/C compressor is driven by the engine
through an electric clutch, drive pulley and belt
arrangement. The compressor is lubricated by refrig-
erant 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. The compressor
pumps the high-pressure refrigerant vapor to the
condenser through the compressor discharge port.
The compressor cannot be repaired. If faulty or
damaged, the entire compressor assembly must be
replaced. The compressor clutch, pulley and clutch
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.
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.
RSPLUMBING - FRONT24-73
PLUMBING - FRONT (Continued)

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 DIAGNOSIS
Excessive noise while the air conditioning compres-
sor is operating can be caused by loose compressor
mounts, a loose compressor clutch, or high operating
pressures in the refrigerant system. Verify compres-
sor drive belt condition, proper compressor mounting,
correct refrigerant charge level, and compressor head
pressure before compressor repair is performed.
With the close tolerances within the compressor, it
is possible to experience a temporary lockup. The
longer the compressor is inactive, the more likely the
condition is to occur. This condition is the result of
normal refrigerant migration within the refrigerant
system caused by ambient temperature changes. The
refrigerant migration may wash the refrigerant oil
out of the compressor.
NOTE: Prior to a vehicle being removed from ser-
vice or stored for more than two weeks, the com-
pressor should be operated to ensure adequate
refrigerant oil distribution throughout the system
components. Turn on the air conditioner for a min-
imum of five minutes with outside air and the high-
est blower speed selected.
BELT NOISE
If the compressor drive belt slips at initial start-up,
it does not necessarily mean the compressor has
failed. The following procedure can be used to iden-
tify a compressor drive belt noise problem.
A. Start the vehicle and run at idle.
B. Turn the air conditioner On and listen for belt
squeal.
C. If belt squeal is heard, turn the air conditioner
Off immediately.
If the belt squeal stops when the air conditioner is
turned Off, perform the following repair procedures.
(1) Using an appropriate sized oil filter wrench or
a strap wrench, grasp the outer diameter of the com-
pressor clutch hub. While facing the compressor,
rotate the hub clockwise, then counterclockwise. If
the hub rotates, proceed to the next step. If the hub
will not rotate, the compressor is internally damaged,
and must be replaced.
(2) Turn the hub clockwise five complete revolu-
tions and remove the tool.
(3) Start the vehicle and run at idle.(4) Turn the air conditioner On. Observe the com-
pressor and the system for normal operation, noting
cooling performance and noise levels. Operate for five
minutes before turning the air conditioner Off. If
acceptable cooling performance is observed during
compressor operation, the compressor does not need
to be replaced.
(5) Inspect the drive belt for wear, damage, and
proper tension. (Refer to 7 - COOLING/ACCESSORY
DRIVE/DRIVE BELTS - DIAGNOSIS AND TEST-
ING).
REMOVAL
REMOVAL - COMPRESSOR
WARNING: REFER TO THE APPLICABLE WARN-
INGS AND CAUTIONS FOR THIS SYSTEM BEFORE
PERFORMING THE FOLLOWING OPERATION (Refer
to 24 - HEATING & AIR CONDITIONING/PLUMBING -
FRONT - WARNING - A/C PLUMBING) and (Refer to
24 - HEATING & AIR CONDITIONING/PLUMBING -
FRONT - CAUTION - A/C PLUMBING).
(1) Recover the refrigerant from the refrigerant
system (Refer to 24 - HEATING & AIR CONDITION-
ING/PLUMBING - FRONT/REFRIGERANT - STAN-
DARD PROCEDURE - REFRIGERANT
RECOVERY).
(2) Disconnect and isolate the battery negative
cable.
(3) Remove the nut that secures the suction line
fitting to the top of the compressor.
(4) Disconnect the suction line fitting from the
compressor suction port.
(5) Remove the O-ring seal and gasket from the
suction line fitting and discard.
(6) Install plugs in, or tape over the opened suc-
tion line fitting and the compressor suction port.
(7) Remove the nut that secures the discharge line
fitting to the top of the compressor.
(8) Disconnect the discharge line fitting from the
compressor discharge port.
(9) Remove the O-ring seal and gasket from the
discharge line fitting and discard.
(10) Install plugs in, or tape over the opened dis-
charge line fitting and the compressor discharge port.
(11) Raise and support the vehicle.
(12) Remove the serpentine accessory drive belt
from the front of the engine (Refer to 7 - COOLING/
ACCESSORY DRIVE/DRIVE BELTS).
(13) Disconnect the engine wire harness connector
from the compressor clutch coil pigtail wire connector
on the top of the compressor (Fig. 5) or (Fig. 6).
(14) On models with the 3.3L and 3.8L engines,
disengage the retainer on the engine wire harness
24 - 74 PLUMBING - FRONTRS
A/C COMPRESSOR (Continued)

INSTALLATION
INSTALLATION
NOTE: If a replacement A/C compressor is being
installed, be certain to check the refrigerant oil level
(Refer to 24 - HEATING & AIR CONDITIONING/
PLUMBING - FRONT/REFRIGERANT OIL - STAN-
DARD PROCEDURE - REFRIGERANT OIL LEVEL).
Use only refrigerant oil of the type recommended
for the compressor in the vehicle.
NOTE: The filter/drier should always be replaced
when the compressor is replaced. This will remove
any contaminants including moisture from the sys-
tem.
(1) Position the A/C compressor into the engine
compartment.
(2) On models with the 2.4L and 2.5L engine,
loosely install the four bolts that secure the compres-
sor to the mounting bracket on the engine (2.4L), or
the cylinder block (2.5L). Tighten the bolts to 28 N´m
(21 ft. lbs.).
(3) On models with the 3.3L and 3.8L engines,
loosely install the two bolts and two nuts that secure
the compressor to the engine. Tighten each of the fas-
teners using the following sequence to 54 N´m (40 ft.
lbs.).
²The upper nut at the front of the compressor.
²The lower nut at the front of the compressor.
²The upper bolt at the rear of the compressor.
²The lower bolt at the rear of the compressor.
(4) On models with the 3.3L and 3.8L engines,
engage the retainer on the engine wire harness com-
pressor clutch coil take out to the bracket on the top
of the compressor.
(5) Connect the engine wire harness connector to
the compressor clutch coil pigtail wire connector on
the top of the compressor.
(6) Reinstall the serpentine accessory drive belt
(Refer to 7 - COOLING/ACCESSORY DRIVE/DRIVE
BELTS).
(7) Lower the vehicle.
(8) Remove the tape or plugs from the compressor
discharge port and the discharge line fitting.
(9) Lubricate a new rubber O-ring seal with clean
refrigerant oil and install it on the discharge line fit-
ting.
(10) Install a new gasket and reconnect the dis-
charge line fitting to the compressor discharge port.
(11) Install the nut that secures the discharge line
fitting to the compressor. Tighten the nut to 23 N´m
(17 ft. lbs.).
(12) Remove the tape or plugs from the compressor
suction port and the suction line fitting.(13) Lubricate a new rubber O-ring seal with clean
refrigerant oil and install it on the suction line fit-
ting.
(14) Install a new gasket and reconnect the suc-
tion line fitting to the compressor suction port.
(15) Install the nut that secures the suction line
fitting to the compressor. Tighten the nut to 23 N´m
(17 ft. lbs.).
(16) Reconnect the battery negative cable.
(17) Evacuate the refrigerant system (Refer to 24 -
HEATING & AIR CONDITIONING/PLUMBING -
FRONT/REFRIGERANT - STANDARD PROCE-
DURE - REFRIGERANT SYSTEM EVACUATE).
(18) Charge the refrigerant system (Refer to 24 -
HEATING & AIR CONDITIONING/PLUMBING -
FRONT/REFRIGERANT - STANDARD PROCE-
DURE - REFRIGERANT SYSTEM CHARGE).
INSTALLATION - A/C COMPRESSOR
MOUNTING BRACKET - 2.4L ENGINE
(1) Position the compressor mounting bracket onto
the engine.
(2) Install the four bolts that secure the compres-
sor mounting bracket to the engine. Tighten the bolts
to 54 N´m (40 ft. lbs.).
(3) Reinstall the A/C compressor onto the mount-
ing bracket (Refer to 24 - HEATING & AIR CONDI-
TIONING/PLUMBING/COMPRESSOR -
INSTALLATION).
A/C CONDENSER
DESCRIPTION
The A/C condenser is integral to a cooling module
which includes the radiator, the electric cooling fan,
the fan shroud, air seals and an automatic transmis-
sion oil cooler. The cooling module is located in the
air flow in the front of the engine compartment
behind the radiator grille. The A/C condenser is a
heat exchanger that allows the high-pressure refrig-
erant gas being discharged from the compressor to
give up its heat to the air passing over the condenser
fins. The A/C condenser may be removed from the
cooling module for service without removing the cool-
ing module from the vehicle.
OPERATION
When the refrigerant gas gives up its heat, it con-
denses. When the refrigerant leaves the condenser, it
has become a high-pressure liquid refrigerant. The
volume of air flowing over the condenser fins is crit-
ical to the proper cooling performance of the air con-
ditioning system. Therefore, it is important that
there are no objects placed in front of the radiator
grille openings in the front of the vehicle or foreign
24 - 76 PLUMBING - FRONTRS
A/C COMPRESSOR (Continued)