Page 3721 of 4284

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 DISCHARGE (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.
STANDARD PROCEDURE - REFRIGERANT
SYSTEM EVACUATE
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).
If the refrigerant system has been open to the
atmosphere, it must be evacuated before the system
can be charged. If moisture and air enters the system
and becomes mixed with the refrigerant, the com-
pressor head pressure will rise above acceptable
operating levels. This will reduce the performance of
the air conditioner and damage the compressor.
Evacuating the refrigerant system will remove the
air and boil the moisture out of the system at near
room temperature. A R-134a refrigerant recovery/re-
cycling/charging station that meets SAE Standard
J2210 must be used to evacuate the refrigerant sys-
tem. See the operating instructions supplied by the
equipment manufacturer for proper care and use of
this equipment. To evacuate the refrigerant system,
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) Remove the caps from the refrigerant system
service ports and attach a manifold gauge set and a
R-134a refrigerant recovery/recycling/charging sta-
tion that meets SAE Standard J2210 to the refriger-
ant system.(2) Open both the suction and discharge valves
and start the charging station vacuum pump.
(3) When the suction gauge has read 88 kPa (26
in. Hg.) vacuum or greater for 45 minutes, close both
the suction and discharge valves and turn off the
vacuum pump. If the refrigerant system fails to
reach the specified vacuum, the system has a leak
that must be corrected. (Refer to 24 - HEATING &
AIR CONDITIONING/PLUMBING - FRONT/RE-
FRIGERANT - STANDARD PROCEDURE -
REFRIGERANT SYSTEM LEAKS).
(4) If the refrigerant system maintains the speci-
fied vacuum for thirty minutes, restart the vacuum
pump, open both the suction and discharge valves,
and evacuate the system for an additional ten min-
utes.
(5) Close both the suction and discharge valves,
and turn off the charging station vacuum pump.
(6) The refrigerant system is now ready to be
charged with R-134a refrigerant. (Refer to 24 -
HEATING & AIR CONDITIONING/PLUMBING -
FRONT/REFRIGERANT - STANDARD PROCE-
DURE - REFRIGERANT SYSTEM CHARGE).
STANDARD PROCEDURE - REFRIGERANT
RECOVERY
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).
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, whenever the refrigerant system must
be opened for service. See the operating instructions
supplied by the equipment manufacturer for the
proper care and use of this equipment.
REFRIGERANT OIL
DESCRIPTION
The refrigerant oil used in R-134a refrigerant sys-
tems is a synthetic-based, PolyAlkylene Glycol (PAG),
wax-free lubricant. Mineral-based R-12 refrigerant
oils are not compatible with PAG oils, and should
never be introduced to an R-134a refrigerant system.
There are different PAG oils available, and each con-
tains a different additive package. The 10S20H com-
pressor used in this vehicle are designed to use an
RSPLUMBING - FRONT24-91
REFRIGERANT (Continued)
Page 3722 of 4284

ND-8 PAG refrigerant oil. Use only refrigerant oil of
this same type to service the refrigerant system.
OPERATION
After performing any refrigerant recovery or recy-
cling operation, always replenish the refrigerant sys-
tem with the same amount of the recommended
refrigerant oil as was removed. Too little refrigerant
oil can cause compressor damage, and too much can
reduce air conditioning system performance. PAG
refrigerant oil is much more hygroscopic than min-
eral oil, and will absorb any moisture it comes into
contact with, even moisture in the air. The PAG oil
container should always be kept tightly capped until
it is ready to be used. After use, recap the oil con-
tainer immediately to prevent moisture contamina-
tion.
STANDARD PROCEDURE - REFRIGERANT OIL
LEVEL
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).
When an air conditioning system is assembled at
the factory, all components except the compressor are
refrigerant oil free. After the refrigerant system has
been charged and operated, the refrigerant oil in the
compressor is dispersed throughout the refrigerant
system. The receiver/drier, evaporator, condenser, and
compressor will each retain a significant amount of
the needed refrigerant oil.
It is important to have the correct amount of oil in
the refrigerant system. This ensures proper lubrica-
tion of the compressor. Too little oil will result in
damage to the compressor. Too much oil will reduce
the cooling capacity of the air conditioning system.
It will not be necessary to check the oil level in the
compressor or to add oil, unless there has been an oil
loss. An oil loss may occur due to a rupture or leak
from a refrigerant line, a connector fitting, a compo-
nent, or a component seal. If a leak occurs, add 30
milliliters (1 fluid ounce) of refrigerant oil to the
refrigerant system after the repair has been made.
Refrigerant oil loss will be evident at the leak point
by the presence of a wet, shiny surface around the
leak.
Refrigerant oil must be added when an receiver/
drier, evaporator or condenser is replaced. See the
Refrigerant Oil Capacities chart for the proper
amount of refrigerant oil to add. When a compressoris replaced, the refrigerant oil must be drained from
the old compressor and measured. Drain all of the
refrigerant oil from the new compressor, then fill the
new compressor with the same amount of fresh new
refrigerant oil that was drained out of the old com-
pressor.
REFRIGERANT OIL CAPACITIES
Front A/C Front & Rear
A/C
COMPONENT ml fl oz ml fl oz
Compressor 150 5.0 220 7.4
Filter-Drier 30 1.0 30 1.0
Condenser 30 1.0 30 1.0
Front Evaporator 60 2.0 60 2.0
Rear Evap. (including
underbody lines)N/A N/A 60 2.0
Compressor Drain and measure the oil
from the old compressor -
See text above.
SUCTION LINE
REMOVAL
The front air conditioner suction line includes the
low side service port on a section of tubing located
near the compressor. On models equipped with the
optional rear air conditioner, the front air conditioner
suction line also includes a suction line hose and
tube extension that connects the front suction line to
the suction line for the rear air conditioner.
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 CONDI-
TIONING/PLUMBING - FRONT/REFRIGERANT -
STANDARD PROCEDURE - REFRIGERANT
RECOVERY).
(2) Disconnect and isolate the battery negative
cable.
(3) Remove the air cleaner top cover and snorkel
from the air cleaner housing located on the right side
of the engine compartment.
(4) Disconnect the drain tube from the wiper mod-
ule drain on the right side of the engine compart-
ment.
24 - 92 PLUMBING - FRONTRS
REFRIGERANT OIL (Continued)
Page 3723 of 4284

(5) Remove the nut that secures the suction line
fitting to the top of the compressor.
(6) Disconnect the suction line fitting from the
compressor suction port.
(7) Remove the seal from the suction line fitting
and discard.
(8) Install plugs in, or tape over the opened suc-
tion line fitting and the compressor suction port.
(9) Disengage the retainer that secures the suction
line routing clip to the filter-drier mounting bracket
on the side of the right front strut tower in the
engine compartment (Fig. 34).
(10) Remove the nut that secures the suction line
and liquid line fittings to the expansion valve.
(11) Disconnect the suction line and liquid line fit-
tings from the expansion valve.
(12) Remove the seals from the suction line and
liquid line fittings and discard.
(13) Install plugs in, or tape over the opened suc-
tion line and liquid line fittings and both expansion
valve ports.
(14) If the vehicle is equipped with the optional
rear air conditioner, go to Step 15. If the vehicle does
not have the optional rear air conditioner, go to Step
21.
(15) Raise and support the vehicle.(16) Cut the tie strap located just forward of the
connections between the underbody plumbing and
the engine compartment plumbing for the rear
heater and air conditioner (Fig. 35).
(17) Disconnect the suction line extension fitting
from the underbody suction line fitting for the rear
air conditioner.
(18) Remove the seal from the underbody suction
line fitting and discard.
(19) Install plugs in, or tape over the opened suc-
tion line fittings.
(20) Lower the vehicle.
(21) Remove the suction line from the engine com-
partment.
INSTALLATION
The front air conditioner suction line includes the
low side service port on a section of tubing located
near the compressor. On models equipped with the
optional rear air conditioner, the front air conditioner
suction line also includes a suction line hose and
tube extension that connects the front suction line to
the suction line for the rear air conditioner.
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).
Fig. 34 Suction Line
1 - EXPANSION VALVE
2 - SUCTION LINE EXTENSION (REAR A/C ONLY)
3 - NUT
4 - ROUTING CLIP
5 - SUCTION LINE
Fig. 35 Underbody Connections
1 - SUCTION LINE EXTENSION
2 - LIQUID LINE EXTENSION
3 - TIE STRAP
4- HEATER LINE EXTENSIONS
5 - UNDERBODY LINES
RSPLUMBING - FRONT24-93
SUCTION LINE (Continued)
Page 3724 of 4284

(1) Position the suction line into the engine com-
partment (Fig. 34).
(2) Remove the tape or plugs from the suction line
and liquid line fittings and both expansion valve
ports.
(3) Lubricate new rubber O-ring seals with clean
refrigerant oil and install them on the suction line
and liquid line fittings.
(4) Reconnect the liquid line and suction line fit-
tings to the expansion valve.
(5) Install and tighten the nut that secures the
suction line and liquid line fittings to the expansion
valve. Tighten the nut to 23 N´m (17 ft. lbs.).
(6) Engage the retainer that secures the suction
line routing clip to the filter-drier mounting bracket
on the side of the right front strut tower in the
engine compartment.
(7) Remove the tape or plugs from the compressor
suction port and the suction line fitting.
(8) Lubricate a new rubber O-ring seal with clean
refrigerant oil and install it on the suction line fit-
ting.
(9) Reconnect the suction line fitting to the com-
pressor suction port.
(10) Install and tighten the nut that secures the
suction line fitting to the compressor. Tighten the nut
to 23 N´m (17 ft. lbs.).
(11) Reconnect the drain tube to the wiper module
drain on the right side of the engine compartment.
(12) Reinstall the air cleaner top cover and snorkel
onto the air cleaner housing located on the right side
of the engine compartment.
(13) Reconnect the battery negative cable.
(14) If the vehicle is equipped with the optional
rear air conditioner, go to Step 15. If the vehicle does
not have the optional rear air conditioner, go to Step
21.
(15) Raise and support the vehicle.
(16) Remove the tape or plugs from the suction
line extension fitting and the underbody suction line
fitting (Fig. 35).
(17) Lubricate a new rubber O-ring seal with clean
refrigerant oil and install it on the underbody suction
line fitting.
(18) Reconnect the suction line extension fitting to
the underbody suction line fitting. Tighten the fit-
tings to 23 N´m (17 ft. lbs.).
(19) Install a new tie strap just forward of the con-
nections between the underbody plumbing and the
engine compartment plumbing for the rear heater
and air conditioner.
(20) Lower the vehicle.
(21) Evacuate the refrigerant system. (Refer to 24
- HEATING & AIR CONDITIONING/PLUMBING -
FRONT/REFRIGERANT - STANDARD PROCE-
DURE - REFRIGERANT SYSTEM EVACUATE).(22) Charge the refrigerant system. (Refer to 24 -
HEATING & AIR CONDITIONING/PLUMBING -
FRONT/REFRIGERANT - STANDARD PROCE-
DURE - REFRIGERANT SYSTEM CHARGE).
SERVICE PORTS
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) Remove the protective cap from the A/C service
port (Fig. 36).
(2) Recover the refrigerant from the refrigerant
system. (Refer to 24 - HEATING & AIR CONDI-
TIONING/PLUMBING - FRONT/REFRIGERANT -
STANDARD PROCEDURE - REFRIGERANT
RECOVERY).
(3) Using a standard Schrader-type valve core tool,
remove the valve core from the A/C service port.
(4) Install a plug in or tape over the opened A/C
service port.
Fig. 36 A/C Service Port - Typical
1 - RIGHT FRONT STRUT TOWER
2 - CONNECTOR
3 - A/C PRESSURE TRANSDUCER
4 - RIGHT WIPER MODULE DRAIN TUBE
5 - HIGH SIDE SERVICE PORT
6 - LIQUID LINE
24 - 94 PLUMBING - FRONTRS
SUCTION LINE (Continued)
Page 3725 of 4284

INSTALLATION
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) Lubricate the A/C service port valve core with
clean refrigerant oil prior to installation. Use only
refrigerant oil of the type recommended for the com-
pressor in the vehicle.
(2) Remove the tape or plug from the A/C service
port.
(3) Using a standard Schrader-type valve core tool,
install and tighten the replacement valve core into
the A/C service port.CAUTION: A valve core that is not fully seated in
the A/C service port can result in damage to the
valve during refrigerant system evacuation and
charge. Such damage may result in a loss of sys-
tem refrigerant while uncoupling the charge adapt-
ers.
(4) Evacuate the refrigerant system. (Refer to 24 -
HEATING & AIR CONDITIONING/PLUMBING -
FRONT/REFRIGERANT - STANDARD PROCE-
DURE - REFRIGERANT SYSTEM EVACUATE).
(5) Charge the refrigerant system. (Refer to 24 -
HEATING & AIR CONDITIONING/PLUMBING -
FRONT/REFRIGERANT - STANDARD PROCE-
DURE - REFRIGERANT SYSTEM CHARGE).
(6) Reinstall the protective cap onto the A/C ser-
vice port.
RSPLUMBING - FRONT24-95
SERVICE PORTS (Continued)
Page 3726 of 4284

PLUMBING - REAR
TABLE OF CONTENTS
page page
EVAPORATOR
DESCRIPTION...........................96
OPERATION.............................96
REMOVAL..............................96
INSTALLATION...........................98
EXPANSION VALVE
DESCRIPTION...........................98
OPERATION.............................98
DIAGNOSIS AND TESTING.................99
EXPANSION VALVE.....................99
REMOVAL..............................99
INSTALLATION...........................99
HEATER CORE
DESCRIPTION..........................100
OPERATION............................100STANDARD PROCEDURE.................100
HEATER CORE FILLING.................100
REMOVAL.............................101
INSTALLATION..........................102
HEATER HOSE
REMOVAL.............................102
INSTALLATION..........................103
SUCTION LINE
REMOVAL.............................103
INSTALLATION..........................104
UNDERBODY LINES
DESCRIPTION..........................105
OPERATION............................105
REMOVAL.............................106
INSTALLATION..........................107
EVAPORATOR
DESCRIPTION
The rear evaporator is located in the rear heater-
A/C unit housing, behind the right rear wheel house.
The evaporator is positioned in the rear heater-A/C
housing so that all air that enters the housing must
pass over the fins of the evaporator before it is dis-
tributed through the system ducts and outlets. How-
ever, air passing over the evaporator fins will only be
conditioned when the compressor is engaged and cir-
culating refrigerant through the evaporator tubes.
The rear heater-A/C unit housing must be removed
from the vehicle to access the evaporator for service.
The evaporator cannot be adjusted or repaired and, if
faulty or damaged, it must be replaced.
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 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 PLUMB-
ING).
(1) Remove the rear heater-A/C unit housing from
the vehicle. (Refer to 24 - HEATING & AIR CONDI-
TIONING/DISTRIBUTION - REAR/REAR HEATER-
A/C 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-
TIONING/PLUMBING - REAR/EXPANSION VALVE
- REMOVAL).
(4) Remove the rubber grommet that seals the
evaporator inlet and outlet tubes to the rear heater-
A/C housing near the expansion valve.
(5) Remove the three screws that secure the upper
half of the rear heater-A/C housing to the lower half
(Fig. 1).
(6) Remove the three small metal spring clips that
secure the upper half of the rear heater-A/C housing
to the lower half.
(7) Carefully separate and remove the upper half
of the rear heater-A/C housing from the lower half.
24 - 96 PLUMBING - REARRS
Page 3727 of 4284

(8) Remove the evaporator from the lower half of
the rear heater-A/C housing.
REMOVAL - EVAPORATOR LINE EXTENSION
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 PLUMB-
ING).
(1) Remove the rear heater-A/C unit housing from
the vehicle. (Refer to 24 - HEATING & AIR CONDI-
TIONING/DISTRIBUTION - REAR/REAR HEATER-
A/C HOUSING - REMOVAL).
(2) Remove the screw that secures the plate that
captures and seals the evaporator line extension
within the base of the rear heater-A/C unit housing
(Fig. 2).
(3) Remove the capture plate from the rear heater-
A/C unit housing base.
(4) Carefully peel back the expansion valve foam
insulator wrap far enough to access the evaporator
line extension sealing plate on the bottom of the
expansion valve (Fig. 3).
(5) Remove the two screws that secure the expan-
sion valve bracket to the lower rear heater-A/C unit
housing.
(6) Remove the nut that secures the expansion
valve bracket to the expansion valve stud.(7) Remove the expansion valve bracket from the
expansion valve stud.
(8) Remove the nut that secures the evaporator
line extension seal plate to the expansion valve stud.
(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 heater-A/C housing
base.
(11) Remove the seals from the evaporator line
extension fittings and discard.
Fig. 1 Rear Evaporator
1 - UPPER REAR HEATER-A/C HOUSING
2 - EVAPORATOR
3 - LOWER REAR HEATER-A/C HOUSING
Fig. 2 Evaporator Line Extension Plate
1 - REAR HEATER-A/C HOUSING BASE
2 - PLATE
3 - EVAPORATOR LINE EXTENSION
Fig. 3 Evaporator Line Extension
1 - UPPER REAR HEATER-A/C HOUSING
2 - LOWER REAR HEATER-A/C HOUSING
3 - EXPANSION VALVE BRACKET
4 - EVAPORATOR LINE EXTENSION
5 - EXPANSION VALVE STUD
6 - INSULATOR WRAP
RSPLUMBING - REAR24-97
EVAPORATOR (Continued)
Page 3728 of 4284

(12) Install plugs in, or tape over the opened evap-
orator line extension fittings and both expansion
valve ports.
INSTALLATION - REAR EVAPORATOR
NOTE: If the evaporator is being replaced, add 60
milliliters (2 fluid ounces) of refrigerant oil to the
refrigerant system. Use only refrigerant oil of the
type recommended for the compressor in the vehi-
cle.
(1) Carefully lower the evaporator and its foam
wrap into the lower half of the rear heater-A/C hous-
ing.
(2) Position the upper half of the rear heater-A/C
housing onto the lower half (Fig. 1).
(3) Install the three small metal spring clips that
secure the upper half of the rear heater-A/C housing
to the lower half.
(4) Install and tighten the three screws that secure
the upper half of the rear heater-A/C housing to the
lower half. Tighten the screws to 2 N´m (18 in. lbs.).
(5) Install the rubber grommet that seals the evap-
orator inlet and outlet tubes to the rear heater-A/C
housing near the expansion valve.
(6) Reinstall the rear expansion valve onto the
rear 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 heater-A/C unit housing into
the vehicle. (Refer to 24 - HEATING & AIR CONDI-
TIONING/DISTRIBUTION - REAR/REAR HEATER-
A/C HOUSING - INSTALLATION).
INSTALLATION - 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 heater-A/C housing
base (Fig. 3).
(4) Position the evaporator line extension seal
plate over the expansion valve stud.
(5) Install and tighten 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 and tighten the two screws that secure
the expansion valve bracket to the lower rear heater-
A/C unit housing. Tighten the screws to 2 N´m (18 in.
lbs.).
(8) Install and tighten 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 heater-A/C
unit housing base (Fig. 2).
(11) Install and tighten the screw that secures the
capture plate to the base of the rear heater-A/C unit
housing. Tighten the screw to 2 N´m (18 in. lbs.).
(12) Reinstall the rear heater-A/C unit housing
into the vehicle. (Refer to 24 - HEATING & AIR
CONDITIONING/DISTRIBUTION - REAR/REAR
HEATER-A/C HOUSING - INSTALLATION).
EXPANSION VALVE
DESCRIPTION
The rear ªHº valve-type thermal expansion valve
(TXV) is located at the rear of the rear heater-A/C
unit housing between the evaporator line extension
and the evaporator coil. High-pressure, low tempera-
ture 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. Models
equipped with the optional Automatic Temperature
Control (ATC) system also have an electric solenoid
that is located on the inboard side of and integral to
the rear expansion valve. The expansion valve is a
factory calibrated unit and cannot be adjusted or
repaired. If faulty or damaged, the expansion valve
must be replaced.
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 expansion valve
solenoid on models equipped with the optional ATC
system electrically blocks refrigerant from passing
through the expansion valve orifice and circulating
24 - 98 PLUMBING - REARRS
EVAPORATOR (Continued)