Fan for heater JEEP GRAND CHEROKEE 2002 WJ / 2.G Workshop Manual

The spring type hose clamp applies constant ten-
sion on a hose connection. To remove a spring type
hose clamp, only use constant tension clamp pliers
designed to compress the hose clamp.
DIAGNOSIS AND TESTING
DIAGNOSIS AND TESTINGÐON-BOARD
DIAGNOSTICS (OBD)
COOLING SYSTEM RELATED DIAGNOSTICS
The powertrain control module (PCM) has been
programmed to monitor certain cooling system com-
ponents:
²If the engine has remained cool for too long a
period, such as with a stuck open thermostat, a Diag-
nostic Trouble Code (DTC) can be set.
²If an open or shorted condition has developed in
the relay circuit controlling the electric radiator fan
or fan control solenoid circuit controling the hydrau-
lic fan, a Diagnostic Trouble Code (DTC) can be set.
If the problem is sensed in a monitored circuit
often enough to indicated an actual problem, a DTC
is stored. The DTC will be stored in the PCM mem-
ory for eventual display to the service technician.
(Refer to 25 - EMISSIONS CONTROL - DESCRIP-
TION).
ACCESSING DIAGNOSTIC TROUBLE CODES
To read DTC's and to obtain cooling system data,
(Refer to 25 - EMISSIONS CONTROL - DESCRIP-
TION).
ERASING TROUBLE CODES
After the problem has been repaired, use the DRB
scan tool to erase a DTC. Refer to the appropriate
Powertrain Diagnostic Procedures service informa-
tion for operation of the DRB scan tool.
DIAGNOSIS AND TESTINGÐPRELIMINARY
CHECKS
ENGINE COOLING SYSTEM OVERHEATING
Establish what driving conditions caused the com-
plaint. Abnormal loads on the cooling system such as
the following may be the cause:
²PROLONGED IDLE
²VERY HIGH AMBIENT TEMPERATURE
Fig. 2 Cooling Module with Electric Fan
1 - RADIATOR
2 - ELECTRIC COOLING FAN CONNECTOR
3 - FAN SHROUD
4 - ELECTRIC COOLING FAN
Fig. 3 Engine Cooling SystemÐ4.0L EngineÐ
Typical
1 - HEATER CORE
2 - TO COOLANT RESERVE/OVERFLOW TANK
3 - THERMOSTAT HOUSING
4 - RADIATOR
5 - WATER PUMP
WJCOOLING 7 - 3
COOLING (Continued)

CONDITION POSSIBLE CAUSES CORRECTION
17. Viscous fan drive not operating
properly.17. Check fan drive operation and replace as
necessary. (Refer to 7 - COOLING/ENGINE/
FAN DRIVE VISCOUS CLUTCH -
DIAGNOSIS AND TESTING).
18. Cylinder head gasket leaking. 18. Check for cylinder head gasket leaks.
(Refer to 7 - COOLING - DIAGNOSIS AND
TESTING). For repair, (Refer to 9 -
ENGINE/CYLINDER HEAD - REMOVAL).
19. Heater core leaking. 19. Check heater core for leaks. (Refer to 24
- HEATING & AIR CONDITIONING/
PLUMBING/HEATER CORE - REMOVAL).
Repair as necessary.
20. Hydraulic fan speed too low or
inopertive.20. Check for
DTC code.
Check fan operation speeds.
Refer to fan speed operation table.
Low power steering pump output. Refer to
power steering pump diagnosis - 4.7L engine.
TEMPERATURE GAUGE
READING IS
INCONSISTENT
(FLUCTUATES, CYCLES
OR IS ERRATIC)1. During cold weather operation,
with the heater blower in the high
position, the gauge reading may
drop slightly.1. A normal condition. No correction is
necessary.
2. Temperature gauge or engine
mounted gauge sensor defective or
shorted. Also, corroded or loose
wiring in this circuit.2. Check operation of gauge and repair if
necessary. Refer to Group 8J, Instrument
cluster.
3. Gauge reading rises when vehicle
is brought to a stop after heavy use
(engine still running)3. A normal condition. No correction is
necessary. Gauge should return to normal
range after vehicle is driven.
4. Gauge reading high after
re-starting a warmed up (hot)
engine.4. A normal condition. No correction is
necessary. The gauge should return to
normal range after a few minutes of engine
operation.
5. Coolant level low in radiator (air
will build up in the cooling system
causing the thermostat to open late).5. Check and correct coolant leaks. (Refer to
7 - COOLING - DIAGNOSIS AND TESTING).
6. Cylinder head gasket leaking
allowing exhaust gas to enter
cooling system causing a thermostat
to open late.6. (a) Check for cylinder head gasket leaks.
(Refer to 7 - COOLING - DIAGNOSIS AND
TESTING).
(b) Check for coolant in the engine oil.
Inspect for white steam emitting from the
exhaust system. Repair as necessary.
WJCOOLING 7 - 7
COOLING (Continued)

CONDITION POSSIBLE CAUSES CORRECTION
NOISY VISCOUS
FAN/DRIVE1. Fan blades loose - 4.0L. 1. Replace fan blade assembly. (Refer to 7 -
COOLING/ENGINE/RADIATOR FAN -
REMOVAL)
2. Fan blades striking a surrounding
object.2. Locate point of fan blade contact and
repair as necessary.
3. Air obstructions at radiator or air
conditioning condenser.3. Remove obstructions and/or clean debris
or insects from radiator or A/C condenser.
4. Thermal viscous fan drive has
defective bearing - 4.0L4. Replace fan drive. Bearing is not
serviceable. (Refer to 7 - COOLING/ENGINE/
RADIATOR FAN - REMOVAL).
INADEQUATE HEATER
PERFORMANCE.1.Thermostat failed in open position
2. Has a Diagnostic trouble Code
(DTC) been set?2. (Refer to 25 - EMISSIONS CONTROL -
DESCRIPTION) for correct procedures and
replace thermostat if necessary
3. Coolant level low 3. (Refer to 7 - COOLING - DIAGNOSIS
AND TESTING).
4. Obstructions in heater hose/
fittings4. Remove heater hoses at both ends and
check for obstructions
5. Heater hose kinked 5. Locate kinked area and repair as
necessary
6. Water pump is not pumping water
to/through the heater core. When
the engine is fully warmed up, both
heater hoses should be hot to the
touch. If only one of the hoses is
hot, the water pump may not be
operating correctly or the heater
core may be plugged. Accessory
drive belt may be slipping causing
poor water pump operation.6. (Refer to 7 - COOLING/ENGINE/WATER
PUMP - DIAGNOSIS AND TESTING). If a
slipping belt is detected, (Refer to 7 -
COOLING/ACCESSORY DRIVE/DRIVE
BELTS - REMOVAL). If heater core
obstruction is detected, (Refer to 7 -
COOLING - STANDARD PROCEDURE) for
cooling system reverse flushing.
STEAM IS COMING
FROM THE FRONT OF
VEHICLE NEAR THE
GRILL AREA WHEN
WEATHER IS WET,
ENGINE IS WARMED UP
AND RUNNING, AND
VEHICLE IS
STATIONARY.
TEMPERATURE GAUGE
IS IN NORMAL RANGE1. During wet weather, moisture
(snow, ice or rain condensation) on
the radiator will evaporate when the
thermostat opens. This opening
allows heated water into the radiator.
When the moisture contacts the hot
radiator, steam may be emitted. This
usually occurs in cold weather with
no fan or airflow to blow it away.1. Occasional steam emitting from this area
is normal. No repair is necessary.
COOLANT COLOR 1. Coolant color is not necessarily
an indication of adequate corrosion
or temperature protection. Do not
rely on coolant color for determining
condition of coolant.1. (Refer to 7 - COOLING/ENGINE/
COOLANT - DESCRIPTION) for coolant
concentration information. Adjust coolant
mixture as necessary.
WJCOOLING 7 - 9
COOLING (Continued)

CONDITION POSSIBLE CAUSES CORRECTION
COOLANT LEVEL
CHANGES IN COOLANT
RESERVE/OVERFLOW
TANK. TEMPERATURE
GAUGE IS IN NORMAL
RANGE1. Level changes are to be expected
as coolant volume fluctuates with
engine temperature. If the level in
the tank was between the FULL and
ADD marks at normal operating
temperature, the level should return
to within that range after operation
at elevated temperatures.1. A normal condition. No repair is necessary.
FAN RUNS ALL THE
TIME1. Fan control sensors inoperative. 1. Check for DTC's. Verify sensor readings.
2. Fan control solenoid stuck9on9. 2. Check fan operation speeds. Refer to fan
speed operation table.
3. Fan control solenoid harness
damaged.3. Check for DTC 1499. Repair as required.
4. Transmission temperature too
high.4. Check for transmission over temp. DTC.
5. Engine coolant temperature too
high.5. (a) Check coolant level. Correct level as
required.
(b) Thermostat stuck. Replace thermostat.
(c) Water pump failed. Replace water pump.
(d) Coolant flow restricted. Clean radiator.
(e) Air flow over radiator obstructed.Remove
obstruction.
DIAGNOSIS AND TESTING - COOLING SYSTEM
LEAKS
ULTRAVIOLET LIGHT METHOD
A leak detection additive is available through the
parts department that can be added to cooling sys-
tem. The additive is highly visible under ultraviolet
light (black light). Pour one ounce of additive into
cooling system. Place heater control unit in HEAT
position. Start and operate engine until radiator
upper hose is warm to touch. Aim the commercially
available black light tool at components to be
checked. If leaks are present, black light will cause
additive to glow a bright green color.
The black light can be used in conjunction with a
pressure tester to determine if any external leaks
exist (Fig. 5).
PRESSURE TESTER METHOD
The engine should be at normal operating temper-
ature. Recheck the system cold if cause of coolant
loss is not located during the warm engine examina-
tion.
WARNING: HOT, PRESSURIZED COOLANT CAN
CAUSE INJURY BY SCALDING.
Fig. 5 Leak Detection Using Black LightÐTypical
1 - TYPICAL BLACK LIGHT TOOL
7 - 10 COOLINGWJ
COOLING (Continued)

(7) After removing fan blade/viscous fan drive
assembly,do notplace viscous fan drive in horizon-
tal position. If stored horizontally, silicone fluid in
the viscous fan drive could drain into its bearing
assembly and contaminate lubricant.
CAUTION: Do not remove water pump pulley-to-wa-
ter pump bolts. This pulley is under belt tension.
(8) Remove four bolts securing fan blade assembly
to viscous fan drive .
CLEANING
Clean the fan blades using a mild soap and water.
Do not use an abrasive to clean the blades.
INSPECTION
WARNING: DO NOT ATTEMPT TO BEND OR
STRAIGHTEN FAN BLADES IF FAN IS NOT WITHIN
SPECIFICATIONS.
CAUTION: If fan blade assembly is replaced
because of mechanical damage, water pump and
viscous fan drive should also be inspected. These
components could have been damaged due to
excessive vibration.
(1) Remove fan blade assembly from viscous fan
drive unit (four bolts).(2) Lay fan on a flat surface with leading edge fac-
ing down. With tip of blade touching flat surface,
replace fan if clearance between opposite blade and
surface is greater than 2.0 mm (.090 inch). Rocking
motion of opposite blades should not exceed 2.0 mm
(.090 inch). Test all blades in this manner.
(3) Inspect fan assembly for cracks, bends, loose
rivets or broken welds. Replace fan if any damage is
found.
INSTALLATION
(1) Assemble fan blade to viscous fan drive.
Tighten mounting bolts to 27 N´m (20 ft. lbs.) torque.
(2) Thread the fan and fan drive onto the water
pump pulley.
CAUTION: When installing a serpentine accessory
drive belt, the belt MUST be routed correctly. If not,
the engine may overheat due to the water pump
rotating in the wrong direction. (Refer to 7 - COOL-
ING/ACCESSORY DRIVE/DRIVE BELTS - REMOVAL)
for correct belt routing.
ENGINE BLOCK HEATER
DESCRIPTION
DESCRIPTIONÐ4.7L ENGINE
WARNING: DO NOT OPERATE ENGINE UNLESS
BLOCK HEATER CORD HAS BEEN DISCONNECTED
FROM POWER SOURCE AND SECURED IN PLACE.
THE POWER CORD MUST BE SECURED IN ITS
RETAINING CLIPS AND ROUTED AWAY FROM
EXHAUST MANIFOLDS AND MOVING PARTS.
An optional engine block heater (Fig. 12) is avail-
able with all models. The heater is equipped with a
power cord. The cord is attached to an engine com-
partment component with tie-straps. The heater
warms the engine providing easier engine starting
and faster warm-up in low temperatures. The heater
is mounted in a core hole of the engine cylinder block
in place of a freeze plug with the heating element
immersed in engine coolant.
DESCRIPTIONÐ4.0L ENGINE
WARNING: DO NOT OPERATE ENGINE UNLESS
BLOCK HEATER CORD HAS BEEN DISCONNECTED
FROM POWER SOURCE AND SECURED IN PLACE.
THE POWER CORD MUST BE SECURED IN ITS
RETAINING CLIPS AND ROUTED AWAY FROM
EXHAUST MANIFOLDS AND MOVING PARTS.
Fig. 11 Fan and Viscous Fan Drive
1 - FAN AND FAN DRIVE
2 - WATER PUMP PULLEY
7 - 32 ENGINEWJ
RADIATOR FAN - 4.0L (Continued)

(2) Insert block heater assembly with element loop
pointing at twelve o'clock (Fig. 19).
(3) With block heater fully seated, tighten center
screw to 2 N´m (17 in. lbs.) torque.
(4) Refill cooling system (Refer to 7 - COOLING -
STANDARD PROCEDURE).
(5) Start and warm the engine. Check for leaks.
ENGINE COOLANT TEMP
SENSOR
DESCRIPTION
The Engine Coolant Temperature (ECT) sensor is
used to sense engine coolant temperature. The sensor
protrudes into an engine water jacket.
The ECT sensor is a two-wire Negative Thermal
Coefficient (NTC) sensor. Meaning, as engine coolant
temperature increases, resistance (voltage) in the
sensor decreases. As temperature decreases, resis-
tance (voltage) in the sensor increases.
OPERATION
At key-on, the Powertrain Control Module (PCM)
sends out a regulated 5 volt signal to the ECT sensor.
The PCM then monitors the signal as it passes
through the ECT sensor to the sensor ground (sensor
return).
When the engine is cold, the PCM will operate in
Open Loop cycle. It will demand slightly richer air-
fuel mixtures and higher idle speeds. This is done
until normal operating temperatures are reached.
The PCM uses inputs from the ECT sensor for the
following calculations:
²for engine coolant temperature gauge operation
through CCD or PCI (J1850) communications
²Injector pulse-width
²Spark-advance curves
²ASD relay shut-down times
²Idle Air Control (IAC) motor key-on steps
²Pulse-width prime-shot during cranking
²O2 sensor closed loop times
²Purge solenoid on/off times
²EGR solenoid on/off times (if equipped)
²Leak Detection Pump operation (if equipped)
²Radiator fan relay on/off times (if equipped)
²Target idle speed
REMOVAL
REMOVALÐ4.0L ENGINE
WARNING: HOT, PRESSURIZED COOLANT CAN
CAUSE INJURY BY SCALDING. COOLING SYSTEM
MUST BE PARTIALLY DRAINED BEFORE REMOV-
ING THE ENGINE COOLANT TEMPERATURE (ECT)
SENSOR. REFER TO GROUP 7, COOLING.
(1) Partially drain cooling system. (Refer to 7 -
COOLING - STANDARD PROCEDURE).
Fig. 18 Drain Plug
1 - COOLANT TEMPERATURE SENSOR
2 - BLOCK DRAIN PLUG
Fig. 19 Engine Block Heater
1 - ENGINE BLOCK HEATER
WJENGINE 7 - 35
ENGINE BLOCK HEATER (Continued)

INSPECTION
The radiator cooling fins should be checked for
damage or deterioration. Inspect cooling fins to make
sure they are not bent or crushed, these areas result
in reduced heat exchange causing the cooling system
to operate at higher temperatures. Inspect the plastic
end tanks for cracks, damage or leaks.
Inspect the radiator neck for damage or distortion.
INSTALLATION
CAUTION: Before installing the radiator or A/C con-
denser, be sure the radiator-to-body and radiator-to-
A/C condenser rubber air seals (Fig. 39) are
properly fastened to their original positions. These
are used at the top, bottom and sides of the radia-
tor and A/C condenser. To prevent overheating,
these seals must be installed to their original posi-
tions.
(1) Equipped with air conditioning: Gently lower
the radiator into the vehicle. Guide the two radiator
alignment dowels through the holes in the rubber air
seals first and then through the A/C support brackets
(Fig. 40). Continue to guide the alignment dowels
into the rubber grommets located in lower radiator
crossmember. The holes in the L-shaped brackets
(located on bottom of A/C condenser) must be posi-
tioned between bottom of rubber air seals and top of
rubber grommets.
(2) Connect the radiator upper and lower hoses
and hose clamps to radiator (Fig. 41).
CAUTION: The tangs on the hose clamps must be
positioned straight down.
(3) Install coolant reserve/overflow tank hose at
radiator (Fig. 41).
(4) Connect both transmission cooler lines at the
radiator (Fig. 41).
(5) Install both radiator mounting bolts (Fig. 41).
(6) Install air inlet duct at grill.
(7) Attach electric fan harness to shroud, then con-
nect harness to connector (Fig. 41).
(8) Install the grill (Refer to 23 - BODY/EXTERI-
OR/GRILLE - INSTALLATION).
(9) Install the fan/viscous fan drive assembly to
the water pump.
(10) Rotate the fan blades (by hand) and check for
interference at fan shroud.
(11) Be sure of at least 25 mm (1.0 inch) between
tips of fan blades and fan shroud.
(12) Fill cooling system (Refer to 7 - COOLING -
STANDARD PROCEDURE).
(13) Connect battery cable at battery.
(14) Start and warm engine. Check for leaks.
RADIATOR FAN MOTOR
DIAGNOSIS AND TESTINGÐELECTRIC
COOLING FAN
The powertrain control module (PCM) will enter a
diagnostic trouble code (DTC) in memory if it detects
a problem in the auxiliary cooling fan relay or circuit.
(Refer to 25 - EMISSIONS CONTROL - DESCRIP-
TION).
If the electric cooling fan is inoperative, check the
15A fuse in the junction block and the 40A fuse in
the Power Distribution Center (PDC) with a 12 volt
test lamp or DVOM. Refer to the inside of the PDC
cover for the exact location of the fuse. If fuses are
okay, refer to ELECTRICAL for cooling fan and relay
circuit schematic.
WATER PUMP - 4.7L
DESCRIPTION
DESCRIPTIONÐWATER PUMP
A centrifugal water pump circulates coolant
through the water jackets, passages, intake manifold,
radiator core, cooling system hoses and heater core.
The pump is driven from the engine crankshaft by a
single serpentine drive belt.
The water pump impeller is pressed onto the rear
of a shaft that rotates in bearings pressed into the
housing. The housing has two small holes to allow
seepage to escape. The water pump seals are lubri-
cated by the antifreeze in the coolant mixture. No
additional lubrication is necessary.
Both heater hoses are connected to fittings on the
timing chain front cover. The water pump is also
mounted directly to the timing chain cover and is
equipped with a non serviceable integral pulley (Fig.
42).
DESCRIPTIONÐWATER PUMP BYPASS
The 4.7L engine uses an internal water/coolant
bypass system. The design uses galleries in the tim-
ing chain cover to circulate coolant during engine
warm-up preventing the coolant from flowing
through the radiator. The thermostat uses a stub
shaft located at the rear of the thermostat (Fig. 43)
to control flow through the bypass gallery.
OPERATION
OPERATIONÐWATER PUMP
A centrifugal water pump circulates coolant
through the water jackets, passages, intake manifold,
WJENGINE 7 - 47
RADIATOR - 4.0L (Continued)

CAUTION: When installing the serpentine accessory
drive belt, belt must be routed correctly. If not,
engine may overheat due to water pump rotating in
wrong direction.
(6) Refill cooling system (Refer to 7 - COOLING -
STANDARD PROCEDURE).
(7) Connect negative battery cable.
(8) Start and warm the engine. Check for leaks.
WATER PUMP - 4.0L
DESCRIPTION
CAUTION: All 4.0L 6-cylinder engines are equipped
with a reverse (counterclockwise) rotating water
pump and thermal viscous fan drive assembly.
REVERSE is stamped or imprinted on the cover of
the viscous fan drive and inner side of the fan. The
letter R is stamped into the back of the water pump
impeller. Engines from previous model years,
depending upon application, may have been
equipped with a forward (clockwise) rotating water
pump. Installation of the wrong water pump or vis-
cous fan drive will cause engine over heating.
A centrifugal water pump circulates coolant
through the water jackets, passages, intake manifold,
radiator core, cooling system hoses and heater core.
The pump is driven from the engine crankshaft by a
single serpentine drive belt.
The water pump impeller is pressed onto the rear
of a shaft that rotates in bearings pressed into the
housing. The housing has two small holes to allow
seepage to escape. The water pump seals are lubri-
cated by the antifreeze in the coolant mixture. No
additional lubrication is necessary (Fig. 45).
DIAGNOSIS AND TESTINGÐWATER PUMP
LOOSE IMPELLER - 4.0L and 4.7L
NOTE: Due to the design of the 4.0L and 4.7L
engine water pumps, testing the pump for a loose
impeller must be done by verifying coolant flow in
the radiator. To accomplish this refer to the follow-
ing procedure.
DO NOT WASTE reusable coolant. If solution is
clean, drain coolant into a clean container for reuse.
(1) Drain coolant until the first row of cores is vis-
ible in the radiator (Refer to 7 - COOLING - STAN-
DARD PROCEDURE) 4.7L Engine or (Refer to 7 -
COOLING - STANDARD PROCEDURE) 4.0L
Engine.(2) Leaving the radiator cap off, start the engine.
Run engine until thermostat opens.
(3) While looking into the radiator through the
radiator fill neck, raise engine rpm to 2000 RPM.
Observe the flow of coolant from the first row of
cores.
(4) If there is no flow or very little flow visable,
replace the water pump.
INSPECTING FOR INLET RESTRICTIONS
Inadequate heater performance may be caused by
a metal casting restriction in the heater hose inlet.
DO NOT WASTE reusable coolant. If solution is
clean, drain the coolant into a clean container for
reuse.
WARNING: DO NOT LOOSEN THE RADIATOR
DRAINCOCK WITH THE SYSTEM HOT AND UNDER
PRESSURE. SERIOUS BURNS FROM THE COOL-
ANT CAN OCCUR.
(1) Drain sufficient coolant from the radiator to
decrease the level below the heater hose inlet. On
4.7L engines this requires complete draining.
(2) Remove the heater hose.
(3) Inspect the inlet for metal casting flash or
other restrictions.
Fig. 45 Water Pump
1 - HEATER HOSE FITTING BORE
2 - WATER PUMP
3 - WATER PUMP HUB
7 - 50 ENGINEWJ
WATER PUMP - 4.7L (Continued)

NOTE: On 4.0L engines remove the pump from the
engine before removing restriction to prevent con-
tamination of the coolant with debris. . On 4.7L
engine remove the fitting from the timing chain
cover, If the restriction is in the timing chain cover,
remove the timing chain cover.
REMOVAL
CAUTION: If the water pump is replaced because of
mechanical damage, the fan blades and viscous fan
drive should also be inspected. These components
could have been damaged due to excessive vibra-
tion.
The water pump impeller is pressed on the rear of
the pump shaft and bearing assembly. The water
pump is serviced only as a complete assembly.
NOTE: The water pump can be replaced without
discharging the A/C system.
WARNING: DO NOT REMOVE THE BLOCK DRAIN
PLUG(S) OR LOOSEN RADIATOR DRAINCOCK
WITH THE SYSTEM HOT AND UNDER PRESSURE.
SERIOUS BURNS FROM COOLANT CAN OCCUR.
DO NOT WASTE reusable coolant. If the solution
is clean, drain coolant into a clean container for
reuse.
(1) Disconnect negative battery cable at battery.
(2) Drain the cooling system (Refer to 7 - COOL-
ING - STANDARD PROCEDURE).
(3) The thermal viscous fan drive is attached
(threaded) to the water pump hub shaft. Remove fan/
viscous fan drive assembly from water pump by turn-
ing mounting nut counterclockwise as viewed from
front. Threads on viscous fan drive areRIGHT
HANDDo not attempt to remove fan/viscous fan
drive assembly from vehicle at this time.
(4) If water pump is being replaced, do not unbolt
fan blade assembly from thermal viscous fan drive.
(5) Remove fan shroud-to-radiator nuts (Fig. 46).
Do not attempt to remove fan shroud at this time.
(6) Remove fan shroud and fan blade/viscous fan
drive assembly from vehicle as a complete unit.
(7) After removing fan blade/viscous fan drive
assembly,do notplace thermal viscous fan drive in
horizontal position. If stored horizontally, silicone
fluid in viscous fan drive could drain into its bearing
assembly and contaminate lubricant.
Loosen but do not remove the water pump pulley
mounting bolts.Remove accessory drive belt (Refer to 7 - COOL-
ING/ACCESSORY DRIVE/DRIVE BELTS - REMOV-
AL).
Remove the water pump pulley.
(8) Remove the idler pulley (located over the water
pump).
WARNING: CONSTANT TENSION HOSE CLAMPS
ARE USED ON MOST COOLING SYSTEM HOSES.
WHEN REMOVING OR INSTALLING, USE ONLY
TOOLS DESIGNED FOR SERVICING THIS TYPE OF
CLAMP, SUCH AS SPECIAL CLAMP TOOL (NUMBER
6094) (Fig. 47) SNAP-ON CLAMP TOOL (NUMBER
HPC-20) MAY BE USED FOR LARGER CLAMPS.
ALWAYS WEAR SAFETY GLASSES WHEN SERVIC-
ING CONSTANT TENSION CLAMPS.
CAUTION: A number or letter is stamped into the
tongue of constant tension clamps (Fig. 48). If
replacement is necessary, use only an original
equipment clamp with matching number or letter.
(9) Remove lower radiator hose from water pump.
Remove heater hose from water pump fitting.
(10) Remove the five pump mounting bolts (Fig.
49) and remove pump from vehicle. Discard old gas-
ket. Note that one of the five bolts is longer than the
other bolts.
(11) If pump is to be replaced, the heater hose fit-
ting must be removed. Note position of fitting before
removal.
Fig. 46 Fan Shroud Mounting
1 - SHROUD FASTENERS
2 - DRAIN COCK
3 - RADIATOR FAN SHROUD
4 - SHROUD FASTENERS
WJENGINE 7 - 51
WATER PUMP - 4.0L (Continued)

CLEANING
Clean the gasket mating surface. Use caution not
to damage the gasket sealing surface.
INSPECTION
Inspect the water pump assembly for cracks in the
housing, Water leaks from shaft seal, Loose or rough
turning bearing or Impeller rubbing either the pump
body or timing chain case/cover.
INSTALLATION
CAUTION: If the water pump is replaced because of
mechanical damage, the fan blades and viscous fan
drive should also be inspected. These components
could have been damaged due to excessive vibra-
tion.
(1) If pump is being replaced, install the heater
hose fitting to the pump. Use a sealant on the fitting
such as MopartThread Sealant With Teflon. Refer to
the directions on the package.
(2) Clean the gasket mating surfaces. If the origi-
nal pump is used, remove any deposits or other for-
eign material. Inspect the cylinder block and water
pump mating surfaces for erosion or damage from
cavitation.
(3) Install the gasket and water pump. The sili-
cone bead on the gasket should be facing the water
pump. Also, the gasket is installed dry. Tighten
mounting bolts to 30 N´m (22 ft. lbs.) torque. Rotate
the shaft by hand to be sure it turns freely.
(4) Connect the radiator and heater hoses to the
water pump.
(5) Position water pump pulley to water pump
hub. Tighten bolts 28 N´m (250 in. lbs.).
Install the idler pulley. Tighten the bolt 47 N´m (35
ft. lbs.).
Fig. 47 Hose Clamp Tool - Typical
1 - HOSE CLAMP TOOL 6094
2 - HOSE CLAMP
Fig. 48 Clamp - Typical
1 - TYPICAL CONSTANT TENSION HOSE CLAMP
2 - CLAMP NUMBER/LETTER LOCATION
3 - TYPICAL HOSE
Fig. 49 Water Pump Remove/Install - Typical
1 - HEATER HOSE FITTING
2 - PUMP GASKET
3 - WATER PUMP
4 - LONG BOLT
5 - BOLTS (4) SHORT
7 - 52 ENGINEWJ
WATER PUMP - 4.0L (Continued)