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 AN ACCIDENTAL
AIRBAG DEPLOYMENT AND POSSIBLE PERSONAL
INJURY OR DEATH.
NOTE: The blower motor is located on the passen-
ger side of the vehicle under the instrument panel.
The blower motor can be removed from the vehicle
without having to remove the HVAC housing.
(1) Disconnect and isolate the negative battery
cable.
(2) Remove the passenger side cowl trim panel
(Refer to 23 - BODY/INTERIOR/COWL TRIM -
REMOVAL).
(3) Pull back the carpet to access the front upper
screw that secures the air inlet housing.
(4) Remove the recirculation door actuator (Refer
to 24 - HEATING & AIR CONDITIONING/CON-
TROLS - FRONT/RECIRCULATION DOOR ACTUA-
TOR - REMOVAL).
(5) Remove the recirculation door actuator wire
lead from the routing clip located on the lower air
inlet housing and position the wire lead aside.
(6) Disconnect the blower motor wire lead connec-
tor from the blower motor resistor block or power
module, depending on application.
(7) Remove the one screw (from the top) that
secures the lower air inlet housing to the upper air
inlet housing (Fig. 8).
(8) Remove the four screws (from the bottom) that
secure the lower air inlet housing to the upper air
inlet housing and the lower HVAC housing.
(9) Push the rubber blower motor wire lead grom-
met through the opening in the lower air inlet hous-
ing (Fig. 9).
(10) Feed the blower motor wire lead through the
opening in the lower air inlet housing and remove
the lower air inlet housing from the vehicle.(11) Position the recirculation-air door as neces-
sary to access and remove the three screws that
secure the blower motor to the lower half of the
HVAC housing.
Fig. 8 Lower Air Inlet Housing
1 - BLOWER MOTOR RESISTOR BLOCK/POWER MODULE
2 - BLOWER MOTOR WIRE LEAD
3 - LOWER HVAC HOUSING
4 - UPPER AIR INLET HOUSING
5 - UPPER SCREW (1)
6 - LOWER AIR INLET HOUSING
7 - RECIRCULATION DOOR ACTUATOR
8 - ACTUATOR WIRE LEAD
9 - LOWER SCREW (4)
Fig. 9 Blower Motor Wire Lead Grommet
1 - BLOWER MOTOR WIRE LEAD GROMMET
24 - 48 DISTRIBUTION - FRONTRS
BLOWER MOTOR (Continued)
(12) Gently flex the recirculation air door far down
enough to remove the blower motor and wheel from
the HVAC housing.
(13) Remove the blower motor and wheel from the
HVAC housing. Note the position of the blower motor
mounting tabs (Fig. 10).
INSTALLATION
(1) Position the blower motor and wheel to the
lower half of the HVAC housing. Align the blower
motor mounting tabs to the correct location on the
HVAC housing.
(2) Gently flex the recirculation-air door far down
enough to install the blower motor and wheel into
the HVAC housing.
(3) Position the recirculation-air door as necessary
to install the three screws that secure the blower
motor to the HVAC housing. Tighten the screws to 2
N´m (17 in. lbs.).
(4) Feed the blower motor wire lead through the
opening in the lower air inlet housing and seat the
rubber grommet into the lower air inlet housing.
(5) Position the recirculation-air door pivot into
the lower air inlet housing.
(6) Install the four screws (from the bottom) that
secure the lower air inlet housing to the upper air
inlet housing and the lower HVAC housing. Tighten
the screws to 2 N´m (17 in. lbs.).
(7) Install the one screw (from the top) that
secures the lower air inlet housing to the upper air
inlet housing. Tighten the screws to 2 N´m (17 in.
lbs.).
(8) Connect the blower motor wire lead connector
to the blower motor resistor block or power module,
depending on application.(9) Install the recirculation door actuator (Refer to
24 - HEATING & AIR CONDITIONING/CONTROLS
- FRONT/RECIRCULATION DOOR ACTUATOR -
INSTALLATION).
(10) Install the recirculation door actuator wire
lead into the routing clip located on the lower air
inlet housing.
(11) Reinstall the carpet.
(12) Install the passenger side cowl trim panel
(Refer to 23 - BODY/INTERIOR/COWL TRIM -
INSTALLATION).
(13) Reconnect the negative battery cable.
(14) Perform the heater-A/C control calibration
procedure (Refer to 24 - HEATING & AIR CONDI-
TIONING/CONTROLS - FRONT/A/C-HEATER CON-
TROL - STANDARD PROCEDURE - HEATER-A/C
CONTROL CALIBRATION).
DEFROSTER DUCT
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) Disconnect and isolate the battery negative
cable.
(2) Remove the instrument panel from the vehicle.
(Refer to 23 - BODY/INSTRUMENT PANEL/IN-
STRUMENT PANEL ASSEMBLY - REMOVAL).
(3) Place the instrument panel face down on a
suitable work surface. Be certain to take the proper
precautions to protect the face of the instrument
panel from cosmetic damage.
(4) Remove the fasteners that secure the defroster
duct to the instrument panel armature.
(5) Remove the defroster duct from the instrument
panel.Fig. 10 Blower Motor Mounting Tabs
1 - BLOWER MOTOR
2 - RUBBER GROMMET
3 - BLOWER MOTOR CONNECTOR
4 - MOUNTING TABS
RSDISTRIBUTION - FRONT24-49
BLOWER MOTOR (Continued)
(5) Disconnect the HVAC wire harness connector
from the blower motor.
(6) Disengage the HVAC wire harness from the
routing clips molded into the outside of the HVAC
housing.
(7) Remove the four screws that secure the top of
the distribution housing to the HVAC housing (Fig.
15).(8) Pull the top of the distribution housing away
from the HVAC housing far enough to disengage the
two hook retainers on the bottom of the distribution
housing from the two receptacles on the HVAC hous-
ing (Fig. 16).
(9) Remove the two screws that secure the upper
air inlet housing to the lower air inlet housing.
(10) Remove the three screws that secure the
upper air inlet housing to the top of the HVAC hous-
ing. Be certain to remove the screw located just
inside the inboard side of the fresh air intake open-
ing.
(11) Remove the upper air inlet housing from the
top of the HVAC housing to expose the recirculation
air door and the blower motor and wheel (Fig. 17).
Fig. 15 Distribution Housing - LHD Shown,
RHD Typical
1 - DISTRIBUTION HOUSING
2 - SCREWS (3)
3 - HVAC WIRING HARNESS
4 - ROUTING CLIP
5 - HVAC HOUSING
Fig. 14 HVAC Housing - RHD Models
1 - BOLT (2)
2 - RETAINER CLIP
3 - BOLT
4 - HVAC HOUSING
Fig. 16 Distribution Housing Retainers - Typical
1 - HVAC HOUSING RECEPTACLES
2 - DISTRIBUTION HOUSING RETAINERS
Fig. 17 Upper Intake Air Housing - LHD Shown,
RHD Typical
1 - HVAC HOUSING
2 - UPPER AIR INLET HOUSING
3 - RECIRCULATION AIR DOOR
4 - BLOWER MOTOR AND WHEEL
24 - 52 DISTRIBUTION - FRONTRS
HVAC HOUSING (Continued)
(12) Remove the screw and washer from the upper
pivot of the recirculation door.
(13) Remove the twelve screws that secure the
upper HVAC housing half to the lower half.
(14) Carefully separate and remove the upper half
of the HVAC housing from the lower half. Be certain
not to lose the rubber grommet for the HVAC wire
harness evaporator temperature sensor take out.
This grommet is located on the inboard side of the
flange around the expansion valve/evaporator tube
opening, where it is captured in a notched area
between the upper and lower HVAC housing halves
(Fig. 18).
INSTALLATION
ASSEMBLY
(1) Position the upper half of the HVAC housing
onto the lower half. Be certain that the rubber grom-
met and the HVAC wire harness take out for the
evaporator temperature sensor are captured in the
notched area between the upper and lower HVAC
housing halves.
(2) Install the twelve screws around the perimeter
of the HVAC housing that secure the upper HVAC
housing half to the lower half. Tighten the screws to
2 N´m (17 in. lbs.).
(3) Position the upper air inlet housing onto the
top of the HVAC housing over the recirculation air
door and the blower motor and wheel. Be certain
that the upper pivot of the recirculation air door is
captured in the pivot receptacle of the upper air inlet
housing.
(4) Install the three screws that secure the upper
air inlet housing to the top of the HVAC housing. Becertain to install the screw located just inside the
inboard side of the fresh air intake opening. Tighten
the screws to 2 N´m (17 in. lbs.).
(5) Install the two screws that secure the upper air
inlet housing to the lower air inlet housing. Tighten
the screws to 2 N´m (17 in. lbs.).
(6) Engage the two hook retainers on the bottom of
the distribution housing to the two receptacles on the
HVAC housing.
(7) Roll the top of the distribution housing up into
position against the HVAC housing.
(8) Install the three screws that secure the top of
the distribution housing to HVAC housing. Tighten
the screws to 2 N´m (17 in. lbs.).
(9) Engage the HVAC wire harness in the routing
clips molded into the outside of the HVAC housing.
(10) Reconnect the HVAC wire harness connector
to the blower motor.
(11) Install the expansion valve onto the evapora-
tor inlet and outlet tube fittings (Refer to 24 - HEAT-
ING & AIR CONDITIONING/PLUMBING - FRONT/
EXPANSION VALVE - INSTALLATION).
(12) Install a new foam seal onto the HVAC hous-
ing seal flange around the fresh air inlet opening and
the expansion valve/evaporator tube opening.
(13) Install the heater core tubes into the heater
core (Refer to 24 - HEATING & AIR CONDITION-
ING/PLUMBING - FRONT/HEATER CORE -
INSTALLATION - HEATER CORE TUBES).
(14) Install the HVAC housing into the vehicle
(Refer to 24 - HEATING & AIR CONDITIONING/
DISTRIBUTION - FRONT/HVAC HOUSING -
INSTALLATION).
INSTALLATION
(1) Position the HVAC housing into the passenger
compartment with the mounting studs located in
their proper mounting holes in the dash panel.
(2) Install the bolt or bolts (depending on applica-
tion) that secure the HVAC housing to the passenger
compartment side of the dash panel. Tighten the
bolt(s) to 3 N´m (26 in. lbs.).
(3) Install the nuts that secure the HVAC housing
to the engine compartment side of the dash panel.
Tighten the nuts to 7 N´m (62 in. lbs.).
(4) On LHD models, install the one bolt that
secures the HVAC housing to the engine compart-
ment side of the dash panel. Tighten the bolt to 4
N´m (35 in. lbs.).
(5) Reinstall the floor distribution duct (Refer to
24 - HEATING & AIR CONDITIONING/DISTRIBU-
TION - FRONT/FLOOR DISTRIBUTION DUCTS -
INSTALLATION).
(6) Install the instrument panel (Refer to 23 -
BODY/INSTRUMENT PANEL/INSTRUMENT
PANEL ASSEMBLY - INSTALLATION).
Fig. 18 HVAC Housing - LHD Shown, RHD Typical
1 - LOWER HVAC HOUSING
2 - UPPER HVAC HOUSING
3 - BLOWER MOTOR AND WHEEL
4 - A/C EVAPORATOR
RSDISTRIBUTION - FRONT24-53
HVAC HOUSING (Continued)
DIAGNOSIS AND TESTING
FRONT 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 A/C expansion valve should only be
tested following testing of the A/C compressor.
NOTE: Liquid CO
2is required to test the A/C expan-
sion valve. This material is available from most
welding supply facilities. Liquid CO
2is also avail-
able from companies which service and sell fire
extinguishers.
When testing the A/C 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 A/C-heater controls so that the A/C
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 motor is operating at the highest speed set-
ting.
(4) Start the engine and allow it to idle. 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 A/C evaporator.
(5) If the refrigerant charge is sufficient, the dis-
charge (high pressure) gauge should read 965 kPa to
1655 kPa (140 psi to 240 psi). The suction (low pres-
sure) gauge should read 138 kPa to 207 kPa (20 psi
to 30 psi). If OK, go to Step 6. If not OK, replace the
faulty A/C expansion valve.
WARNING:
PROTECT THE SKIN AND EYES FROM EXPOSURE
TO LIQUID CO
2OR PERSONAL INJURY CAN
RESULT.
(6) If the suction (low pressure) gauge reads
within the specified range, freeze the A/C expansion
valve for 30 seconds using liquid CO
2or another suit-able super-cold material.Do not spray R-134a or
R-12 refrigerant on the A/C expansion valve for
this test.The suction (low pressure) gauge reading
should drop by 69 kPa (10 psi). If OK, go to Step 7 If
not OK, replace the faulty A/C expansion valve.
(7) Allow the expansion valve control head to thaw.
The suction (low pressure) gauge reading should sta-
bilize at 138 kPa to 207 kPa (20 psi to 30 psi). If not
OK, replace the faulty A/C expansion valve.
(8) When expansion valve testing is complete, test
the overall A/C system performance (Refer to 24 -
HEATING & AIR CONDITIONING - DIAGNOSIS
AND TESTING - A/C PERFORMANCE TEST).
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) Disconnect and isolate the battery negative
cable.
(3) Remove the air cleaner housing from 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.
(5) Disconnect the wire harness connector from the
A/C pressure transducer (Fig. 16).
(6) Remove the screw that secures the front liquid
line rear section fitting to the top of the receiver/
drier.
(7) Disconnect the liquid line fitting from the
receiver/drier outlet port.
(8) Remove the seal from the liquid line fitting and
discard.
(9) Install plugs in, or tape over the opened liquid
line fitting and the receiver/drier outlet port.
(10) Remove the nut that secures the suction line
and liquid line fittings to the stud on the A/C expan-
sion valve.
(11) Disconnect the suction line and liquid line fit-
tings from the A/C expansion valve and move the
lines out of the way.
(12) Remove the seals from the suction line and
liquid line fittings and discard.
24 - 82 PLUMBING - FRONTRS
EXPANSION VALVE (Continued)
heater core inlet and outlet ports. Removable heater
core tubes attach to the ports by use of a sealing
plate secured with a screw to the heater core tank.
This removable heater core tube arrangement allows
the heater core to be serviced without removing the
HVAC housing from the vehicle.
OPERATION
Engine coolant is circulated through heater hoses
to the heater core at all times. As the coolant flows
through the heater core, heat removed from the
engine is transferred to the heater core fins and
tubes. Air directed through the heater core picks up
the heat from the heater core fins. The blend door
allows control of the heater output air temperature
by regulating the amount of air that is flowing
through the heater core within the HVAC housing.
The heater core cannot be repaired and, if faulty or
damaged, it must be replaced.
REMOVAL
FRONT HEATER CORE TUBES
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) Drain the engine cooling system (Refer to 7 -
COOLING - STANDARD PROCEDURE - COOLING
SYSTEM DRAIN).
(2) Disconnect and isolate the battery negative
cable.
(3) Disconnect the heater hoses from the heater
core tubes (Refer to 24 - HEATING & AIR CONDI-
TIONING/PLUMBING/HEATER INLET HOSE -
REMOVAL) and (Refer to 24 - HEATING & AIR
CONDITIONING/PLUMBING/HEATER RETURN
HOSE - REMOVAL).(4) Remove the silencer from beneath the driver
side end of the instrument panel.
NOTE: Take the proper precautions to protect the
carpeting below the heater core from spilled engine
coolant and have absorbent toweling readily avail-
able to clean up any spills.
(5) Remove the screw that secures the heater core
tube sealing plate to the heater core supply and
return ports (Fig. 17).
(6) Push both heater core tubes simultaneously
toward the dash panel far enough to disengage their
fittings from the heater core supply and return ports.
(7) Install plugs in, or tape over the opened heater
core tube fittings and both heater core ports.
(8) Pull both heater core tubes simultaneously
slightly away from the distribution housing and rear-
ward far enough to disengage the engine compart-
ment ends of the tubes from the dash panel seal.
(9) Remove the heater core tubes and sealing plate
as a unit from beneath the instrument panel.
(10) Use absorbent toweling to clean up any
engine coolant spills from the preceding operation.
Fig. 17 Heater Core Tubes - LHD Shown, RHD
Typical
1 - SEAL
2 - HEATER CORE TUBES
3 - SCREW
4 - HEATER CORE
5 - DISTRIBUTION HOUSING
6 - SEALING PLATE
24 - 84 PLUMBING - FRONTRS
HEATER CORE (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)
(5) Install the rear evaporator line extension onto
the expansion valve (Refer to 24 - HEATING & AIR
CONDITIONING/PLUMBING - REAR/EVAPORA-
TOR - INSTALLATION - EVAPORATOR LINE
EXTENSION).
(6) Install the foam insulator wrap over the rear
expansion valve.
(7) Install the rear HVAC housing (Refer to 24 -
HEATING & AIR CONDITIONING/DISTRIBUTION/
HVAC HOUSING - INSTALLATION).
(8) Run the HVAC Cooldown Test to verify proper
operation.
HEATER CORE
DESCRIPTION
The rear heater core is located near the front of
the rear HVAC housing, behind the right rear wheel
house. It is a heat exchanger made of rows of tubes
and fins. One end of the core is fitted with a molded
plastic tank that includes integral heater core inlet
and outlet nipples. The rear heater core can be ser-
viced without removing the rear HVAC housing from
the vehicle.
OPERATION
Engine coolant is circulated through underbody
heater hoses to the rear heater core at all times. As
the coolant flows through the rear heater core, heat
removed from the engine is transferred to the heater
core fins and tubes. Air directed through the heater
core picks up the heat from the heater core fins. The
rear blend door allows control of the rear heater out-
put air temperature by controlling how much of the
air flowing through the rear HVAC housing is
directed through the heater core.
The rear heater core cannot be repaired and, if
faulty or damaged, it must be replaced.
STANDARD PROCEDURE
REAR HEATER CORE FILLING
In its final installed position, the rear heater core
is positioned higher than the radiator fill cap. There-
fore, when the cooling system is drained and refilled,
gravity will not refill the heater core with coolant to
the proper level. This may result in two problems:1.
Insufficient coolant level in the engine cooling sys-
tem, which may result in engine overheating.2.Air
entrapped within the rear heater core, which may
result in insufficient rear heater performance. There
are two methods that may be employed to prevent
these problems:1.Pre-filling of the rear heater core.
2.Thermal cycling of the engine cooling system. Fol-lowing are descriptions of both prevention methods,
as well as a method to verify rear heater perfor-
mance.
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 - HEATER PLUMBING).
PRE-FILLING
If the rear heater core or the rear HVAC housing
have been removed from the vehicle for service, the
rear heater core may be pre-filled with the proper
engine coolant mixture prior to reconnecting the
heater hoses to the heater core hose fittings.
(1) The heater core should be installed in the rear
HVAC housing, and the rear HVAC housing should
be installed in the vehicle.
(2) Take the proper precautions to protect the car-
peting below the rear heater core from spilled engine
coolant and have absorbent toweling readily avail-
able to mop up any spills.
(3) Insert the small end of an appropriate funnel
into the upper hose fitting of the heater core (Fig. 4).
(4) Carefully pour the proper pre-mixed engine
coolant solution into the rear heater core through a
funnel until coolant begins to appear at the lower
hose fitting of the heater core.
(5) Use absorbent toweling to clean up any engine
coolant spills from the preceding operation.
(6) Reconnect the heater hoses to the rear heater
core (Refer to 24 - HEATING & AIR CONDITION-
ING/PLUMBING - REAR/HEATER HOSE - INSTAL-
LATION).
Fig. 4 Pre-Filling Heater Core - Typical
1 - REAR HEATER CORE
24 - 102 PLUMBING - REARRS
A/C EXPANSION VALVE (Continued)