2005 CHRYSLER CARAVAN oil pressure

REMOVAL
WARNING: ON VEHICLES EQUIPPED WITH AIR-
BAGS, DISABLE THE AIRBAG SYSTEM BEFORE
ATTEMPTING ANY STEERING WHEEL, STEERING
COLUMN, OR INSTRUMENT PANEL COMPONENT
DIAGNOSIS OR SERVICE. DISCONNECT AND ISO-
LATE THE BATTERY NEGATIVE (GROUND) CABLE,
THEN WAIT TWO MINUTES FOR THE AIRBAG SYS-
TEM CAPACITOR TO DISCHARGE BEFORE PER-
FORMING FURTHER DIAGNOSIS OR SERVICE. THIS
IS THE ONLY SURE WAY TO DISABLE THE AIRBAG
SYSTEM. FAILURE TO TAKE THE PROPER PRE-
CAUTIONS COULD RESULT IN ACCIDENTAL AIR-
BAG DEPLOYMENT AND POSSIBLE PERSONAL
INJURY.
(1) Remove the HVAC housing (Refer to 24 -
HEATING & AIR CONDITIONING/DISTRIBUTION/
HVAC HOUSING - REMOVAL).
(2) Disassemble the HVAC housing to access the
evaporator (Refer to 24 - HEATING & AIR CONDI-
TIONING/DISTRIBUTION/HVAC HOUSING - DIS-
ASSEMBLY).
(3) Carefully lift the evaporator and its foam wrap
out of the lower half of the HVAC housing as a unit
(Fig. 15). Be certain not to lose the clam shell type
rubber seal that is fitted to the evaporator inlet and
outlet tubes where they exit the HVAC housing.
INSTALLATION
NOTE: If the evaporator is being replaced, add 50
milliliters (1.7 fluid ounces) of refrigerant oil to the
refrigerant system. Use only refrigerant oil of the
type recommended for the A/C compressor in the
vehicle.
(1) Carefully lower the evaporator and its foam
wrap into the lower half of the HVAC housing as a
unit. Be certain that the clam shell type rubber seal
is fitted to the evaporator inlet and outlet tubes
where they exit the HVAC housing.
(2) Assemble the HVAC housing (Refer to 24 -
HEATING & AIR CONDITIONING/DISTRIBUTION/
HVAC HOUSING - ASSEMBLY).
(3) Install the HVAC housing (Refer to 24 - HEAT-
ING & AIR CONDITIONING/DISTRIBUTION/HVAC
HOUSING - INSTALLATION).
EXPANSION VALVE
DESCRIPTION
The front ªHº valve-type thermal expansion valve
(TXV) is located at the dash panel between the liquid
and suction lines, and the A/C evaporator. The
assembly consists of an aluminum H-valve body and
a thermal sensor. On RG models, the evaporator tem-
perature sensor is installed on the top of the expan-
sion valve.
OPERATION
High-pressure, low temperature liquid refrigerant
from the liquid line passes through the expansion
valve orifice, converting it into a low-pressure, low-
temperature mixture of liquid and gas before it
enters the evaporator coil. A mechanical sensor in the
expansion valve control head monitors the tempera-
ture and pressure of the refrigerant leaving the evap-
orator coil through the suction line, and adjusts the
orifice size at the liquid line to let the proper amount
of refrigerant into the evaporator coil to meet the
vehicle cooling requirements. Controlling the refriger-
ant flow through the A/C evaporator ensures that
none of the refrigerant leaving the evaporator is still
in a liquid state, which could damage the compressor.
The A/C expansion valve is a factory calibrated
unit and cannot be adjusted or repaired and, if faulty
or damaged, it must be replaced.
Fig. 15 HVAC Housing - LHD Shown, RHD Typical
1 - LOWER HVAC HOUSING
2 - UPPER HVAC HOUSING
3 - BLOWER MOTOR AND WHEEL
4 - A/C EVAPORATOR
RSPLUMBING - FRONT24-81
A/C EVAPORATOR (Continued)

(13) Install plugs in, or tape over the opened suc-
tion line and liquid line fittings and both expansion
valve ports.
(14) Remove the two screws that secure the A/C
expansion valve to the evaporator tube tapping plate.
(15) On RG models, disconnect the HVAC wire
harness connector from the evaporator temperature
sensor.
(16) Remove the A/C expansion valve from the
evaporator inlet and outlet tube fittings.
(17) Remove the seals from the evaporator inlet
and outlet tube fittings and discard.
(18) Install plugs in, or tape over the opened evap-
orator inlet and outlet tube fittings and both expan-
sion valve ports.
(19) On RG models, remove the evaporator tem-
perature sensor retainer and evaporator temperature
sensor from the A/C expansion valve, if required.
INSTALLATION
NOTE: Any grease removed with the evaporator
temperature sensor must be replaced. Failure to do
so could result in poor A/C performance.
(1) On RG models, install the evaporator tempera-
ture sensor and retainer onto the A/C expansion
valve, if removed.
(2) Remove the tape or plugs from the evaporator
inlet and outlet tube fittings and both ports on the
back of the A/C expansion valve.(3) Lubricate new rubber O-ring seals with clean
refrigerant oil and install them on the evaporator
inlet and outlet tube fittings.
(4) Position the A/C expansion valve onto the evap-
orator inlet and outlet tube fittings.
(5) Install the two screws that secure the A/C
expansion valve to the evaporator tube tapping plate
plate. Tighten the screws to 11 N´m (97 in. lbs.).
(6) On RG models, connect the HVAC wire harness
connector to the evaporator temperature sensor.
(7) Remove the tape or plugs from the front liquid
line rear section and suction line fittings for the
expansion valve and both ports on the front of the
expansion valve.
(8) Lubricate new rubber O-ring seals with clean
refrigerant oil and install them on the front liquid
line rear section and suction line fittings for the
expansion valve.
(9) Connect the liquid line and suction line fittings
to the expansion valve.
(10) Install the nut that secures the suction line
and liquid line fittings to the stud on the expansion
valve. Tighten the nut to 23 N´m (17 ft. lbs.).
(11) Remove the tape or plugs from the liquid line
rear section fitting and the receiver/drier outlet port.
(12) Lubricate a new rubber O-ring seal with clean
refrigerant oil and install it on the liquid line fitting.
(13) Connect the liquid line fitting to the receiver/
drier outlet port.
(14) Install the screw that secures the liquid line
fitting to the receiver/drier. Tighten the screw to 11
N´m (97 in. lbs.).
(15) Connect the wire harness connector to the A/C
pressure transducer.
(16) Connect the drain tube to the wiper module
drain on the right side of the engine compartment.
(17) Install the air cleaner housing.
(18) Reconnect the battery negative cable.
(19) Evacuate the refrigerant system (Refer to 24 -
HEATING & AIR CONDITIONING/PLUMBING -
FRONT/REFRIGERANT - STANDARD PROCE-
DURE - REFRIGERANT SYSTEM EVACUATE).
(20) Charge the refrigerant system (Refer to 24 -
HEATING & AIR CONDITIONING/PLUMBING -
FRONT/REFRIGERANT - STANDARD PROCE-
DURE - REFRIGERANT SYSTEM CHARGE).
HEATER CORE
DESCRIPTION
The heater core is located in the distribution hous-
ing, which is attached to the HVAC housing, behind
the instrument panel. It is a heat exchanger made of
rows of tubes and fins. One end of the core is fitted
with a molded plastic tank, which includes integral
Fig. 16 A/C Expansion Valve - LHD Shown, RHD
Typical
1 - A/C PRESSURE TRANSDUCER
2 - EVAPORATOR TEMPERATURE SENSOR (RG ONLY)
3 - A/C EXPANSION VALVE
4 - SUCTION LINE
5 - HIGH SIDE SERVICE PORT
6 - LIQUID LINE
RSPLUMBING - FRONT24-83
EXPANSION VALVE (Continued)

HEATER RETURN HOSE
REMOVAL
WARNING: REFER TO THE APPLICABLE WARN-
INGS AND CAUTIONS FOR THIS SYSTEM BEFORE
PERFORMING THE FOLLOWING OPERATION (Refer
to 24 - HEATING & AIR CONDITIONING/PLUMBING -
WARNING).
NOTE: The heater return tube is constructed from
formed steel tubing and rubber hoses. Depending
on application, the ends are secured to the heater
core, engine oil cooler or the engine by spring ten-
sion clamps.
(1) Drain the engine cooling system (Refer to 7 -
COOLING - STANDARD PROCEDURE - COOLING
SYSTEM DRAIN).
(2) Using spring tension clamp pliers, compress
and slide the clamps off of each end of the hose being
removed (Fig. 23), (Fig. 24) or (Fig. 25).
CAUTION:
DO NOT apply excessive pressure on heater tubes
or connections when removing heater hoses.
Excessive pressure may damage or deform the
tubes/heater core, causing an engine coolant leak.
(3) Disconnect each hose end by carefully twisting
the hose back and forth on the tube or nipple, while
gently pulling it away from the end of the tube or
nipple.
NOTE:
Replacement of the heater return hoses will be
required if the hose ends are cut for removal.
(4) If necessary, carefully cut the hose end and
peel the hose off of the tube or nipple.
Fig. 23 Heater Return Hose - 2.4L Shown, 2.5L
Typical
1 - ENGINE OUTLET NIPPLE
2 - HEATER INLET HOSE
3 - HEATER CORE OUTLET
4 - HEATER CORE INLET
5 - SCREW
6 - HEATER TUBE
7 - HEATER RETURN HOSE
8 - ENGINE INLET NIPPLE
Fig. 24 Heater Return Hose - 3.3L/3.8L W/O Rear
Heater
1 - ENGINE OUTLET NIPPLE
2 - HEATER CORE OUTLET
3 - HEATER CORE INLET
4 - HEATER RETURN TUBE (TYPICAL)
24 - 88 PLUMBING - FRONTRS

(7) Lubricate a new rubber O-ring seal with clean
refrigerant oil and install it on the liquid line fitting.
(8) Reconnect the A/C liquid line to the receiver/
drier.
(9) Install the bolt that secures the A/C liquid line
to the receiver/drier. Tighten the bolt to 11 N´m (97
in. lbs.).
(10) If equipped, reinstall the A/C ground strap
eyelet terminal connector onto the weld stud on the
top of the right front strut tower (if equipped).
(11) If equipped, install the nut that secures the
A/C ground strap to the weld stud. Tighten the nut
to 12 N´m (106 in. lbs.)
(12) Install the A/C pressure transducer (Refer to
24 - HEATING & AIR CONDITIONING/CONTROLS
- FRONT/A/C PRESSURE TRANSDUCER - INSTAL-
LATION).
(13) Connect the drain tube to the wiper module
drain on the right side of the engine compartment.
(14) Install the air cleaner housing into the right
side of the engine compartment.
(15) On RHD models, install the liquid line into
the retaining bracket located at the top of the dash
panel.
(16) If the vehicle is equipped with the optional
rear heating-A/C system, go to Step 17. If the vehicle
does not have the optional rear heating-A/C system,
go to Step 23.
(17) Raise and support the vehicle.
(18) Remove the tape or plugs from the A/C liquid
line extension fitting and the underbody liquid line
fitting.
(19) Lubricate a new rubber O-ring seal with clean
refrigerant oil and install it on the underbody liquid
line fitting.
(20) Connect the A/C liquid line extension fitting
to the underbody liquid line fitting. Tighten the fit-
tings to 23 N´m (17 ft. lbs.).
(21) Install a new tie strap just forward of the con-
nections between the underbody plumbing and the
engine compartment plumbing for the rear heating-
A/C system.
(22) Lower the vehicle.
(23) Reconnect the negative battery cable.
(24) Evacuate the refrigerant system (Refer to 24 -
HEATING & AIR CONDITIONING/PLUMBING -
FRONT/REFRIGERANT - STANDARD PROCE-
DURE - REFRIGERANT SYSTEM EVACUATE).
(25) Charge the refrigerant system (Refer to 24 -
HEATING & AIR CONDITIONING/PLUMBING -
FRONT/REFRIGERANT - STANDARD PROCE-
DURE - REFRIGERANT SYSTEM CHARGE).RECEIVER / DRIER
DESCRIPTION
The receiver/drier is mounted in a bracket secured
to the right front strut tower in the engine compart-
ment. The receiver/drier is connected between the
front and rear sections of the liquid line between the
condenser outlet and the evaporator inlet. The receiv-
er/drier cannot be repaired. If the receiver/drier is
faulty or damaged, or if the refrigerant system has
been contaminated or left open to the atmosphere for
an indeterminable period or if the A/C compressor
has failed, it must be replaced.
OPERATION
The receiver/drier performs a filtering action to
prevent foreign material in the refrigerant from con-
taminating the expansion valve. Desiccant inside the
receiver/drier canister absorbs any moisture which
may have entered and become trapped within the
refrigerant system. In addition, during periods of
high demand air conditioner operation, the receiver/
drier acts as a reservoir to store surplus refrigerant.
Refrigerant enters the receiver/drier as a high-pres-
sure, low temperature liquid.
REMOVAL
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) Remove the air cleaner housing from the right
side of the engine compartment.
(3) Remove the bolt that secures the liquid line
front section fitting to the top of the receiver/drier
(Fig. 30).
(4) Disconnect the liquid line fitting from the
receiver/drier inlet port.
(5) Remove the O-ring seal from the liquid line fit-
ting and discard.
(6) Install plugs in, or tape over the opened liquid
line fitting and the receiver/drier inlet port.
24 - 92 PLUMBING - FRONTRS
LIQUID LINE (Continued)

(7) Remove the bolt that secures the liquid line
rear section fitting to the top of the receiver/drier.
(8) Disconnect the liquid line fitting from the
receiver/drier outlet port.
(9) Remove the seal from the liquid line fitting and
discard.
(10) Install plugs in, or tape over the opened liquid
line fitting and the receiver/drier outlet port.
(11) Remove the two nuts that secure the receiver/
drier mounting bracket to the weld studs on the side
of the right front strut tower.
(12) Remove the receiver/drier and mounting
bracket unit from the studs.
INSTALLATION
NOTE: If the receiver/drier is being replaced, add 25
milliliters (0.8 fluid ounce) of refrigerant oil to the
refrigerant system. Use only refrigerant oil of the
type recommended for the A/C compressor in the
vehicle.(1) Position the receiver/drier and mounting
bracket unit onto the weld studs on the side of the
right front strut tower.
(2) Install the two nuts that secure the receiver/
drier mounting bracket to the studs. Tighten the
nuts to 10 N´m (89 in. lbs.).
(3) Remove the tape or plugs from the liquid line
rear section fitting for the receiver/drier and the
receiver/drier outlet port.
(4) Lubricate a new rubber O-ring seal with clean
refrigerant oil and install it on the liquid line fitting.
(5) Reconnect the liquid line fitting to the receiver/
drier outlet port on the top of the receiver/drier.
(6) Install the bolt that secures the liquid line fit-
ting to the receiver/drier. Tighten the bolt to 11 N´m
(97 in. lbs.).
(7) Remove the tape or plugs from the liquid line
front section fitting for the receiver/drier and the
receiver/drier inlet port.
(8) Lubricate a new rubber O-ring seal with clean
refrigerant oil and install it on the liquid line fitting.
(9) Reconnect the liquid line fitting to the receiver/
drier inlet port on the top of the receiver/drier.
(10) Install the bolt that secures the liquid line fit-
ting to the receiver/drier. Tighten the bolt to 11 N´m
(97 in. lbs.).
(11) Reinstall the air cleaner housing into the
right side of the engine compartment.
(12) Evacuate the refrigerant system (Refer to 24 -
HEATING & AIR CONDITIONING/PLUMBING -
FRONT/REFRIGERANT - STANDARD PROCE-
DURE - REFRIGERANT SYSTEM EVACUATE).
(13) Charge the refrigerant system (Refer to 24 -
HEATING & AIR CONDITIONING/PLUMBING -
FRONT/REFRIGERANT - STANDARD PROCE-
DURE - REFRIGERANT SYSTEM CHARGE).
REFRIGERANT
DESCRIPTION
The refrigerant used in this air conditioning sys-
tem is a HydroFluoroCarbon (HFC), type R-134a.
Unlike R-12, which is a ChloroFluoroCarbon (CFC),
R-134a refrigerant does not contain ozone-depleting
chlorine. R-134a refrigerant is a non-toxic, non-flam-
mable, clear, and colorless liquefied gas. Even though
R-134a does not contain chlorine, it must be
reclaimed and recycled just like CFC-type refriger-
ants. This is because R-134a is a greenhouse gas and
can contribute to global warming.
Fig. 30 Reciever/Drier - LHD Shown, RHD Typical
1 - A/C GROUND STRAP (IF EQUIPPED)
2 - NUT (IF EQUIPPED)
3 - WELD STUD (IF EQUIPPED)
4 - A/C PRESSURE TRANSDUCER
5 - WELD STUD (2)
6 - A/C EXPANSION VALVE
7 - A/C LIQUID LINE (REAR SECTION)
8 - LIQUID LINE EXTENSION (REAR A/C ONLY)
9 - NUT (2)
10 - RECEIVER/DRIER
11 - ROUTING CLIP
12 - A/C LIQUID LINE (FRONT SECTION)
RSPLUMBING - FRONT24-93
RECEIVER / DRIER (Continued)

PLUMBING - REAR
TABLE OF CONTENTS
page page
A/C EVAPORATOR
DESCRIPTION.........................98
OPERATION...........................98
REMOVAL
REAR A/C EVAPORATOR...............98
REAR A/C EVAPORATOR LINE
EXTENSION.........................99
INSTALLATION
REAR A/C EVAPORATOR..............100
REAR A/C EVAPORATOR LINE
EXTENSION........................100
A/C EXPANSION VALVE
DESCRIPTION........................100
OPERATION..........................100
DIAGNOSIS AND TESTING
REAR A/C EXPANSION VALVE..........101
REMOVAL............................101
INSTALLATION........................101
HEATER CORE
DESCRIPTION........................102
OPERATION..........................102
STANDARD PROCEDURE
REAR HEATER CORE FILLING..........102REMOVAL............................103
INSTALLATION........................104
HEATER HOSES
REMOVAL............................104
INSTALLATION........................105
LIQUID LINE
REMOVAL............................105
INSTALLATION........................106
SUCTION LINE
REMOVAL............................106
INSTALLATION........................107
UNDERBODY LINES
DESCRIPTION........................108
OPERATION..........................108
REMOVAL
UNDERBODY HEATER TUBES..........109
UNDERBODY REFRIGERANT LINES......110
INSTALLATION
UNDERBODY HEATER TUBES..........112
UNDERBODY REFRIGERANT LINES......112
A/C EVAPORATOR
DESCRIPTION
The rear A/C evaporator is located in the rear
HVAC housing, behind the right rear wheel house.
The evaporator is positioned in the rear housing so
that all air that enters the housing must pass over
the fins of the evaporator coils before it is distributed
through the system ducts and outlets. However, air
passing over the evaporator fins will only be condi-
tioned when the compressor is engaged and circulat-
ing refrigerant through the evaporator tubes. The
rear HVAC housing must be removed from the vehi-
cle to access the A/C evaporator for service.
OPERATION
Refrigerant enters the rear evaporator from the
rear expansion valve as a low-temperature, low-pres-
sure liquid. As air flows over the fins of the evapora-
tor, the humidity in the air condenses on the fins,
and the heat from the air is absorbed by the refrig-
erant. Heat absorption causes the refrigerant to boil
and vaporize. The refrigerant becomes a low-pressure
gas when it leaves the evaporator.
REMOVAL
REAR A/C EVAPORATOR
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), (Refer to 24 -
HEATING & AIR CONDITIONING/PLUMBING -
FRONT - CAUTION - A/C PLUMBING), and (Refer to
24 - HEATING & AIR CONDITIONING/PLUMBING -
FRONT - WARNING - HEATER PLUMBING).
(1) Remove the rear HVAC housing from the vehi-
cle (Refer to 24 - HEATING & AIR CONDITIONING/
DISTRIBUTION/HVAC HOUSING - REMOVAL).
(2) Remove the rear evaporator line extension from
the expansion valve (Refer to 24 - HEATING & AIR
CONDITIONING/PLUMBING - REAR/EVAPORA-
TOR - REMOVAL - EVAPORATOR LINE EXTEN-
SION).
(3) Remove the rear expansion valve from the rear
evaporator (Refer to 24 - HEATING & AIR CONDI-
24 - 98 PLUMBING - REARRS

(9) Remove the evaporator line extension seal
plate from the expansion valve stud.
(10) Remove the evaporator line extension from
the expansion valve and the rear HVAC housing
base.
(11) Remove the seals from the evaporator line
extension fittings and discard.
(12) Install plugs in, or tape over the opened evap-
orator line extension fittings and both expansion
valve ports.
INSTALLATION
REAR A/C EVAPORATOR
NOTE: If the rear A/C evaporator is being replaced,
add 50 milliliters (1.7 fluid ounces) of refrigerant oil
to the refrigerant system. Use only refrigerant oil of
the type recommended for the A/C compressor in
the vehicle.
(1) Carefully lower the rear A/C evaporator and its
foam wrap into the lower half of the rear HVAC
housing.
(2) Position the upper half of the rear HVAC hous-
ing onto the lower half.
(3) Install the three metal spring clips that secure
the upper half of the rear HVAC housing to the lower
half.
(4) Install the three screws that secure the upper
half of the rear HVAC housing to the lower half.
Tighten the screws to 2 N´m (17 in. lbs.).
(5) Install the rubber grommet that seals the evap-
orator inlet and outlet tubes to the rear HVAC hous-
ing near the expansion valve.
(6) Reinstall the rear expansion valve onto the
rear A/C evaporator (Refer to 24 - HEATING & AIR
CONDITIONING/PLUMBING - REAR/EXPANSION
VALVE - INSTALLATION).
(7) Reinstall the rear evaporator extension line
onto the expansion valve (Refer to 24 - HEATING &
AIR CONDITIONING/PLUMBING - REAR/EVAPO-
RATOR - INSTALLATION - EVAPORATOR EXTEN-
SION LINE).
(8) Reinstall the rear HVAC housing into the vehi-
cle (Refer to 24 - HEATING & AIR CONDITIONING/
DISTRIBUTION - REAR/REAR HEATER-A/C
HOUSING - INSTALLATION).
REAR A/C EVAPORATOR LINE EXTENSION
(1) Remove the tape or plugs from the evaporator
line extension fittings and both expansion valve
ports.
(2) Lubricate new rubber O-ring seals with clean
refrigerant oil and install them on the evaporator
line extension fittings.(3) Position the evaporator line extension to the
expansion valve and the rear HVAC housing base.
(4) Position the evaporator line extension seal
plate over the expansion valve stud.
(5) Install the nut that secures the evaporator line
extension seal plate to the expansion valve stud.
Tighten the nut to 23 N´m (17 ft. lbs.).
(6) Position the expansion valve bracket over the
expansion valve stud.
(7) Install the two screws that secure the expan-
sion valve bracket to the lower rear HVAC housing.
Tighten the screws to 2 N´m (17 in. lbs.).
(8) Install the nut that secures the expansion
valve bracket to the expansion valve stud. Tighten
the nut to 23 N´m (17 ft. lbs.).
(9) Carefully restore the expansion valve foam
insulator wrap back around the expansion valve.
(10) Position the plate that captures and seals the
evaporator line extension onto the rear HVAC hous-
ing base.
(11) Install the screw that secures the capture
plate to the base of the rear HVAC housing. Tighten
the screw to 2 N´m (17 in. lbs.).
(12) Install the rear HVAC housing into the vehi-
cle (Refer to 24 - HEATING & AIR CONDITIONING/
DISTRIBUTION/HVAC HOUSING -
INSTALLATION).
A/C EXPANSION VALVE
DESCRIPTION
The rear ªHº valve-type thermal expansion valve
(TXV) is located at the rear of the rear HVAC hous-
ing between the evaporator line extension and the
evaporator coil. High-pressure, low temperature liq-
uid refrigerant from the liquid line passes through
the expansion valve orifice, converting it into a low-
pressure, low-temperature mixture of liquid and gas
before it enters the evaporator coil.
OPERATION
A mechanical sensor in the expansion valve control
head monitors the temperature and pressure of the
refrigerant leaving the evaporator coil through the
suction line, and adjusts the orifice size at the liquid
line to let the proper amount of refrigerant into the
evaporator coil to meet the vehicle cooling require-
ments. Controlling the refrigerant flow through the
evaporator ensures that none of the refrigerant leav-
ing the evaporator is still in a liquid state, which
could damage the compressor.
The rear A/C expansion valve cannot be adjusted
or repaired and, if faulty or damaged, it must be
replaced.
24 - 100 PLUMBING - REARRS
A/C EVAPORATOR (Continued)

DIAGNOSIS AND TESTING
REAR A/C EXPANSION VALVE
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 expansion valve should only be tested
following testing of the compressor.
NOTE: Liquid CO
2is required to test the expansion
valve. This material is available from most welding
supply facilities. Liquid CO
2is also available from
companies which service and sell fire extinguish-
ers.
When testing the expansion valve, the work area
and the vehicle temperature must be 21É to 27É C
(70É to 85É F). To test the expansion valve:
(1) Connect a charging station or manifold gauge
set to the refrigerant system service ports. Verify the
refrigerant charge level.
(2) Close all doors, windows and vents to the pas-
senger compartment.
(3) Set the heater-air conditioner controls so that
the compressor is operating, the temperature control
is in the highest temperature position, the mode door
is directing the output to the floor outlets, and the
blower is operating at the highest speed setting.
(4) Start the engine and allow it to idle at 1000
rpm. After the engine has reached normal operating
temperature, allow the passenger compartment to
heat up. This will create the need for maximum
refrigerant flow into the evaporator.
(5) If the refrigerant charge is sufficient, the dis-
charge (high pressure) gauge should read 965 to 1655
kPa (140 to 240 psi). The suction (low pressure)
gauge should read 140 kPa to 207 kPa (20 psi to 30
psi). If OK, go to Step 6. If not OK, replace the faulty
expansion valve.
WARNING: PROTECT THE SKIN AND EYES FROM
EXPOSURE TO LIQUID CO
2. PERSONAL INJURY
CAN RESULT.
(6)
If the suction (low pressure) gauge reads within
the specified range, freeze the expansion valve control
head for 30 seconds using liquid CO
2or another suit-
able super-cold material.Do not spray R-134a or
R-12 refrigerant on the expansion valve controlhead for this test.
The suction (low pressure) gauge
reading should drop by 10 psi. If OK, go to Step 7 If
not OK, replace the faulty expansion valve.
(7) Allow the expansion valve control head to thaw.
The suction (low pressure) gauge reading should sta-
bilize at 140 kPa to 240 kPa (20 psi to 30 psi). If not
OK, replace the faulty expansion valve.
(8) When expansion valve testing is complete, test
the overall air conditioner performance (Refer to 24 -
HEATING & AIR CONDITIONING - DIAGNOSIS
AND TESTING - A/C PERFORMANCE TEST).
Remove all test equipment before returning the vehi-
cle to service.
REMOVAL
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), (Refer to 24 -
HEATING & AIR CONDITIONING/PLUMBING -
FRONT - CAUTION - A/C PLUMBING), and (Refer to
24 - HEATING & AIR CONDITIONING/PLUMBING -
FRONT - WARNING - HEATER PLUMBING).
(1) Remove the rear HVAC housing from the vehi-
cle (Refer to 24 - HEATING & AIR CONDITIONING/
DISTRIBUTION/HVAC HOUSING - REMOVAL).
(2) Carefully remove the foam insulator wrap from
the rear expansion valve.
(3) Remove the rear evaporator line extension from
the expansion valve (Refer to 24 - HEATING & AIR
CONDITIONING/PLUMBING - REAR/EVAPORA-
TOR - REMOVAL - EVAPORATOR LINE EXTEN-
SION).
(4) Remove the two screws that secure the expan-
sion valve to the evaporator tube sealing plate.
(5) Remove the expansion valve from the evapora-
tor tubes.
(6) Remove the seals from the evaporator tube fit-
tings and discard.
(7) Install plugs in, or tape over the opened evap-
orator tube fittings and both expansion valve ports.
INSTALLATION
(1) Remove the tape or plugs from the rear A/C
evaporator tube fittings and both expansion valve
ports.
(2) Lubricate new rubber O-ring seals with clean
refrigerant oil and install them on the rear evapora-
tor tube fittings.
(3) Position the expansion valve onto the evapora-
tor tubes.
(4) Install the two screws that secure the rear A/C
expansion valve to the evaporator tube sealing plate.
Tighten the screws to 11 N´m (97 in. lbs.).
RSPLUMBING - REAR24 - 101
A/C EXPANSION VALVE (Continued)