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)
FRONT HEATER CORE
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 silencer boot fasteners located
around the base of the lower steering shaft from the
dash panel so that it may be pushed aside.
(2) Remove the brake lamp switch from its mount-
ing bracket (Refer to 8 - ELECTRICAL/LAMPS/
LIGHTING - EXTERIOR/BRAKE LAMP SWITCH -
REMOVAL).
(3) Disconnect the power brake booster input rod
(push rod) from the pin on the brake pedal arm
(Refer to 5 - BRAKES - ABS/HYDRAULIC/ME-
CHANICAL/POWER BRAKE BOOSTER -
REMOVAL).
(4) Remove the heater core tubes (Refer to 24 -
HEATING & AIR CONDITIONING/PLUMBING/
HEATER CORE - REMOVAL).
(5) Remove the two screws that secure the heater
core mounting plate to the distribution housing.
(6) While pulling the accelerator pedal upward
(Fig. 18) and pushing the brake pedal downward
(Fig. 19) far enough for clearance, pull the heater
core out of the distribution housing.
(7) Use absorbent toweling to mop up any engine
coolant spills from the preceding operation. Also, if
the heater core was leaking, use absorbent toweling
and reach into the heater core opening to mop up
any residual engine coolant within the distribution
housing.
INSTALLATION
FRONT HEATER CORE TUBES
(1) Remove the plugs or tape from both heater core
tube fittings and both heater core ports.
(2) Position the heater core tubes and sealing plate
as a unit beneath the instrument panel.
Fig. 18 Accelerator Pedal - LHD Shown, RHD Typical
1 - HEATER CORE
Fig. 19 Brake Pedal - LHD Shown, RHD Typical
1 - HEATER CORE
2 - BRAKE PEDAL
RSPLUMBING - FRONT24-85
HEATER CORE (Continued)
(3) Align the engine compartment ends of both
heater core tubes with the openings in the dash
panel seal and push them simultaneously forward
through the seal far enough to engage the heater
core ends of the tubes with the heater core supply
and return ports.
(4) Position both heater core tubes and the sealing
plate simultaneously to the heater core supply and
return ports.
NOTE: The heater core tubes each have a slot that
must be indexed to a location tab within each of the
heater core ports. Adjust the position of the tubes
as required so that the sealing plate fits flush
against the heater core supply and return ports,
which indicates that the tubes are properly indexed.
(5) Index both heater core tubes to the heater core
ports.
(6) Install the screw that secures the heater core
tube sealing plate to the heater core supply and
return ports. Tighten the screw to 3 N´m (27 in. lbs.).
(7) Install the silencer under the driver side end of
the instrument panel.
(8) Connect the heater hoses to the heater hose
tubes (Refer to 24 - HEATING & AIR CONDITION-
ING/PLUMBING/HEATER INLET HOSE - INSTAL-
LATION) and(Refer to 24 - HEATING & AIR
CONDITIONING/PLUMBING/HEATER RETURN
HOSE - INSTALLATION).
(9) Reconnect the battery negative cable.
(10) Refill the engine cooling system (Refer to 7 -
COOLING - STANDARD PROCEDURE - COOLING
SYSTEM REFILL).
FRONT HEATER CORE
(1) While pushing the brake pedal downward and
pulling the accelerator pedal upward far enough for
clearance, slide the heater core into the distribution
housing.
(2) Install the two screws that secure the heater
core mounting plate to the distribution housing.
Tighten the screws to 2 N´m (17 in. lbs.).(3) Install the heater core tubes (Refer to 24 -
HEATING & AIR CONDITIONING/PLUMBING/
HEATER CORE - INSTALLATION).
(4) Reconnect the power brake booster input rod
(push rod) to the pin on the brake pedal arm (Refer
to 5 - BRAKES/HYDRAULIC/MECHANICAL/
POWER BRAKE BOOSTER - INSTALLATION).
(5) Reinstall the brake lamp switch into its mount-
ing bracket (Refer to 8 - ELECTRICAL/LAMPS/
LIGHTING - EXTERIOR/BRAKE LAMP SWITCH -
INSTALLATION).
(6) Reinstall the silencer boot around the base of
the lower steering shaft on the dash panel.
(7) Reconnect the battery negative cable.
(8) Refill the engine cooling system (Refer to 7 -
COOLING - STANDARD PROCEDURE - COOLING
SYSTEM REFILL).
(9) Operate system for two thermostat cycles to
assure the elimination of any air that may be
trapped within the cooling system.
HEATER INLET 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 inlet hose 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).
24 - 86 PLUMBING - FRONTRS
HEATER CORE (Continued)
(2) Using spring tension clamp pliers, compress
and slide the clamps off of each end of the hose being
removed (Fig. 20), (Fig. 21) or (Fig. 22).
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 inlet 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.
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 -
WARNING).
(1) Using spring tension clamp pliers, compress
and slide each clamp away from the end of the hose
being installed.(2) Install each hose by carefully twisting the hose
back and forth while gently pushing it onto the tube
or nipple end.
(3) Using spring tension clamp pliers, compress
and slide the clamps onto each end of the hose being
installed.
(4) Refill the engine cooling system (Refer to 7 -
COOLING - STANDARD PROCEDURE - COOLING
SYSTEM REFILL).
Fig. 20 Heater Inlet 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. 21 Heater Inlet 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)
Fig. 22 Heater Inlet Hose - 3.3L/3.8L With Rear
Heater
1 - STUD
2 - HEATER CORE OUTLET
3 - HEATER CORE INLET
4 - TO ENGINE OUTLET NIPPLE
5 - TO UNDERBODY PLUMBING
6 - TO HEATER RETURN TUBE & HOSE
RSPLUMBING - FRONT24-87
HEATER INLET HOSE (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
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 -
WARNING).
(1) Using spring tension clamp pliers, compress
and slide the clamp away from the end of the heater
return hose.
(2) Install each hose end by carefully twisting the
hose back and forth while gently pushing it onto the
tube.
(3) Using spring tension clamp pliers, compress
and slide the clamps onto each end of the heater
return hose.
(4) Refill the engine cooling system (Refer to 7 -
COOLING - STANDARD PROCEDURE).
LIQUID LINE
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).NOTE: The front A/C liquid line is serviced in two
sections. The front section connects between the
A/C condenser and the receiver/drier and includes
the high side service port. The rear section con-
nects between the receiver/drier and the expansion
valve and includes the fitting for the A/C pressure
transducer. On models equipped with the optional
rear heating-A/C system, the rear section of the
front A/C liquid line also includes a hose and tube
extension that connects the front liquid line to the
liquid line for the rear A/C system.
FRONT SECTION
(1) Recover the refrigerant from the refrigerant
system (Refer to 24 - HEATING & AIR CONDITION-
ING/PLUMBING - FRONT/REFRIGERANT - STAN-
DARD PROCEDURE - REFRIGERANT SYSTEM
RECOVERY).
(2) Disconnect and isolate the negative battery
cable.
(3) Remove the air cleaner housing from the right
side of the engine compartment.
(4) Remove the two large screws that secure the
front fascia and the outboard ends of the radiator
sight shield to the radiator closure panel crossmem-
ber (Fig. 26).
(5) Remove the five small screws that secure the
front fascia grille inserts to the radiator sight shield.
(6) Remove the radiator sight shield from the radi-
ator closure panel crossmember.
(7) Remove the nut that secures the A/C liquid line
to the right side of the A/C condenser (Fig. 27).
Fig. 25 HEATER HOSES - 3.3/3.8L With Rear Heater
1 - STUD
2 - HEATER CORE OUTLET
3 - HEATER CORE INLET
4 - TO ENGINE OUTLET NIPPLE
5 - TO UNDERBODY PLUMBING
6 - TO HEATER RETURN TUBE & HOSE
Fig. 26 Radiator Sight Shield - Typical
1 - LARGE SCREWS (2)
2 - SMALL SCREWS (5)
3 - RADIATOR SIGHT SHIELD
4 - GRILLE INSERTS
5 - FRONT FASCIA
RSPLUMBING - FRONT24-89
HEATER RETURN HOSE (Continued)
(8) Disconnect the A/C liquid line from the A/C
condenser and remove and discard the O-ring seal
and gasket.
(9) Install plugs in, or tape over the opened liquid
line fitting and the condenser outlet port.
(10) Disengage the retainer that secures the liquid
line routing clip to the top of the right frame rail
ahead of the front strut tower in the engine compart-
ment (Fig. 28).
(11) Remove the bolt that secures the front section
of the A/C liquid line to the receiver/drier.
(12) Disconnect the A/C liquid line from the receiv-
er/drier and remove and discard the O-ring seal.
(13) Install plugs in, or tape over the opened liquid
line fitting and the receiver/drier inlet port.
(14) Remove the front section of the A/C liquid line
from the engine compartment.
REAR SECTION
(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 negative battery
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) Remove the A/C pressure transducer (Refer to
24 - HEATING & AIR CONDITIONING/CONTROLS
- FRONT/A/C PRESSURE TRANSDUCER -
REMOVAL).(6) If equipped, remove the nut that secures the
A/C ground strap to the weld stud on the top of the
right front strut tower (Fig. 28).
(7) If equipped, remove the A/C ground strap eye-
let terminal connector from the weld stud.
(8) Remove the bolt that secures the rear section
of the A/C liquid line to the receiver/drier.
(9) Disconnect the A/C liquid line from the receiv-
er/drier and remove and discard the O-ring seal.
(10) Install plugs in, or tape over the opened liquid
line fitting and the receiver/drier outlet port.
(11) Remove the nut that secures the A/C suction
line and the A/C liquid line to the A/C expansion
valve.
(12) Disconnect the A/C suction line and the A/C
liquid line from the A/C expansion valve and remove
and discard the O-ring seals.
(13) Install plugs in, or tape over the opened suc-
tion line and liquid line fittings and both expansion
valve ports.
(14) On RHD models, remove the rear section of
the A/C liquid line from the retaining bracket located
at the top of the dash panel
Fig. 27 A/C Condenser Connections
1 - A/C CONDENSER
2 - A/C DISCHARGE LINE
3 - A/C LIQUID LINE
4 - NUT (2)Fig. 28 A/C Liquid Line - 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)
24 - 90 PLUMBING - FRONTRS
LIQUID LINE (Continued)
(15) If the vehicle is equipped with the optional
rear heating-A/C system, go to Step 16. If the vehicle
is not equipped with the optional rear heating-A/C
system, go to Step 22.
(16) Raise and support the vehicle.
(17) Cut the tie strap located just forward of the
connections between the underbody plumbing and
the engine compartment plumbing for the rear heat-
ing-A/C system (Fig. 29).
(18) Disconnect the A/C liquid line extension fit-
ting from the underbody liquid line fitting for the
rear A/C system.
(19) Remove the O-ring seal from the underbody
liquid line fitting and discard.
(20) Install plugs in, or tape over the opened liquid
line fittings.
(21) Lower the vehicle.
(22) Remove the rear section of the A/C liquid line
from the engine compartment.
INSTALLATION
FRONT SECTION
(1) Position the front section of the A/C liquid line
into the engine compartment.
(2) Remove the tape or plugs from the liquid line
fitting and the receiver/drier inlet port.
(3) Lubricate a new rubber O-ring seal with clean
refrigerant oil and install it onto the liquid line fit-
ting.
(4) Connect the A/C liquid line to the receiver/
drier.(5) Install the bolt that secures the A/C liquid line
to the receiver/drier. Tighten the bolt to 11 N´m (97
in. lbs.).
(6) Engage the retainer that secures the liquid line
routing clip to the top of the right frame rail ahead of
the front strut tower in the engine compartment.
(7) Remove the tape or plugs from the condenser
outlet port and the liquid line fitting.
(8) Lubricate a new rubber O-ring seal with clean
refrigerant oil and install it and a new gasket onto
the liquid line fitting.
(9) Connect the A/C liquid line to the A/C con-
denser.
(10) Install the nut that secures the A/C liquid line
to the A/C condenser. Tighten the nut to 23 N´m (17
ft. lbs.).
(11) Position the radiator sight shield onto the
radiator closure panel crossmember.
(12) Install the five small screws that secure the
front fascia grille inserts to the radiator sight shield.
Tighten the screws to 2 N´m (17 in. lbs.).
(13) Install the two large screws that secure the
front fascia and the outboard ends of the radiator
sight shield to the radiator closure panel crossmem-
ber. Tighten the screws to 6 N´m (53 in. lbs.).
(14) Reinstall the air cleaner housing into the
right side of the engine compartment.
(15) Reconnect the negative battery cable.
(16) Evacuate the refrigerant system (Refer to 24 -
HEATING & AIR CONDITIONING/PLUMBING -
FRONT/REFRIGERANT - STANDARD PROCE-
DURE - REFRIGERANT SYSTEM EVACUATE).
(17) Charge the refrigerant system (Refer to 24 -
HEATING & AIR CONDITIONING/PLUMBING -
FRONT/REFRIGERANT - STANDARD PROCE-
DURE - REFRIGERANT SYSTEM CHARGE).
REAR SECTION
(1) Position the rear section of the A/C liquid line
into the engine compartment.
(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 onto the suction line
and liquid line fittings.
(4) Reconnect the A/C liquid line and the A/C suc-
tion line to the A/C expansion valve.
(5) Install the nut that secures the rear section of
the A/C liquid line and the A/C suction line to the
A/C expansion valve. Tighten the nut to 23 N´m (17
ft. lbs.).
(6) Remove the tape or plugs from the liquid line
fitting and the receiver/drier outlet port.
Fig. 29 Underbody A/C Line Connections
1 - SUCTION LINE EXTENSION TUBE
2 - LIQUID LINE EXTENSION TUBE
3 - RETAINING STRAP
4 - REAR HEATER EXTENSION TUBES
5 - UNDERBODY REFRIGERANT LINES
RSPLUMBING - FRONT24-91
LIQUID LINE (Continued)