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(1) Clean the mating areas of the intake manifold
and thermostat housing.
(2) Install the thermostat (spring side down) into the recessed machined groove on the intake manifold (Fig. 22).
(3) Install the gasket on the intake manifold and
over the thermostat (Fig. 22).
Fig.21SPRINGCLAMPSIZELOCATION
1 - SPRING CLAMP SIZE LOCATION
Fig.22Thermostat–5.9LEngines
1 - THERMOSTAT HOUSING 2 - GASKET 3 - INTAKE MANIFOLD 4 - THERMOSTAT 5 - MACHINED GROOVE
(4) Position the thermostat housing to the intake manifold. Note: The word FRONT stamped on hous- ing (Fig. 23). For adequate clearance, this must be placed towards the front of the vehicle. The housing is slightly angled forward after the installation to the intake manifold.
(5) Install
the housing-to-intake manifold bolts.
Tighten the bolts to 23 N·m (200 in. lbs.).
ENGINE
7 - 50
ENGINE COOLANT THERMOSTAT- 5.7L/5.9L (Continued)DR
Fig.23ThermostatPosition—5.9LEngines
(6) Install the radiator upper hose to the thermo-
stat housing.
CAUTION: When installing the serpentine accessory drive belt, the belt must be routed correctly. If not, the engine may overheat due to the water pump rotating in wrong direction. Refer to (Fig. 24) for the correct 5.9L engine belt routing. The correct belt with correct length must be used.
(7) Air Conditioned vehicles; Install the generator.
Tighten the bolts to 41 N·m (30 ft. lbs.).
(8) Install the support bracket (generator mount- ing bracket-to-intake manifold). (Fig. 19). Tighten the bolts to 54 N·m (40 ft. lbs.).
(9) Install the accessory drive belt (Fig. 20)(Refer - COOLING/ACCESSORY DRIVE/DRIVE
to BELTS - INSTALLATION).
(10) Fill the cooling system (Refer to 7 - COOLING
- STANDARD PROCEDURE).
(11) Connect battery negative cable. (12) Start and warm the engine. Check for leaks.
Fig.24BeltRouting–5.9LEngines
1 - IDLER PULLEY 2 - GENERATOR PULLEY 3 - A/C COMPRESSOR PULLEY 4 - IF W/OUT A/C 5 - POWER STEERING PUMP PULLEY 6 - WATER PUMP PULLEY 7 - CRANKSHAFT PULLEY 8 - AUTOMATIC TENSIONER
ENGINE COOLANT THERMOSTAT - 3.7L/4.7L DESCRIPTION
CAUTION: Do not operate the engine without a ther- mostat, except for servicing or testing.
A pellet-type thermostat controls the operating temperature of the engine by controlling the amount of coolant flow to the radiator. On all engines the thermostat is closed below 195°F (90°C). Above this temperature, coolant is allowed to flow to the radia- tor. This provides quick engine warm up and overall temperature control. On the 3.7L4.7L engine the thermostat is designed to block the flow of the cool- ant bypass journal by 50% instead of completely blocking the flow. This design controls coolant tem- perature more accurately (Fig. 25).
The same thermostat is used for winter and sum- mer seasons. An engine should not be operated with- out a thermostat, except for servicing or testing. Operating without a thermostat causes other prob- lems. These are: longer engine warmup time, unreli- able warmup exhaust
performance,
increased
DR ENGINE COOLANT THERMOSTAT - 3.7L/4.7L (Continued)
ENGINE
7 - 51
emissions and crankcase condensation. This conden- sation can result in sludge formation.
the Diagnosis section of this group for other probable causes.
The DTC can also be accessed through the DRBIIIt scan tool. Refer to the appropriate Power- train Diagnostic Procedures information for diagnos- tic information and operation of the DRBIIIt scan tool.
REMOVAL
WARNING: DO NOT LOOSEN THE RADIATOR DRAINCOCK WITH THE COOLING SYSTEM HOT AND PRESSURIZED. SERIOUS BURNS FROM THE COOLANT CAN OCCUR.
Do not waste reusable coolant. If the solution is clean, drain the coolant into a clean container for reuse.
If the thermostat is being replaced, be sure that the replacement is the specified thermostat for the vehicle model and engine type.
(1) Disconnect the negative battery cable. (2) Drain the cooling system (Refer to 7 - COOL-
ING - STANDARD PROCEDURE).
(3) Raise and support the vehicle. (4) Remove the splash shield. (5) Remove the lower radiator hose clamp and the
lower radiator hose at the thermostat housing.
(6) Remove
the
thermostat housing mounting
bolts, thermostat housing and thermostat (Fig. 26).
INSTALLATION
(1) Clean the mating areas of the timing chain
cover and the thermostat housing.
(2) Install the thermostat (spring side down) into the recessed machined groove on the timing chain cover (Fig. 26).
(3) Position the thermostat housing on the timing
chain cover.
(4) Install the housing-to-timing chain cover bolts.
Tighten the bolts to 13 N·m (112 in. lbs.).
CAUTION: The housing must be tightened evenly and the thermostat must be centered into the recessed groove in the timimg chain cover. If not, it may result in a cracked housing, damaged timing chain cover threads or coolant leaks.
(5) Install the lower radiator hose on the thermo-
stat housing.
(6) Install the splash shield. (7) Lower the vehicle. (8) Fill the cooling system (Refer to 7 - COOLING
- STANDARD PROCEDURE).
(9) Connect negative battery cable. (10) Start and warm the engine. Check for leaks.
Fig.25ThermostatCrossSectionView3.7L/4.7L
1 - FROM HEATER AND DEGAS CONTAINER 2 - FROM RADIATOR 3 - TO WATER PUMP 4 - ENGINE BYPASS 5 - THERMOSTAT
OPERATION
The wax pellet is located in a sealed container at the spring end of the thermostat. When heated, the pellet expands, overcoming closing spring tension and water pump pressure to force the valve to open.
DIAGNOSIS AND TESTING—THERMOSTAT
ON-BOARD DIAGNOSTICS
All gasoline powered models are equipped with On-Board Diagnostics for certain cooling system com- ponents. Refer to On-Board Diagnostics (OBD) in the Diagnosis section of this group for additional infor- mation. If the powertrain control module (PCM) detects low engine coolant temperature, it will record a Diagnostic Trouble Code (DTC) in the PCM mem- ory. Do not change a thermostat for lack of heat as indicated by the instrument panel gauge or by poor heater performance unless a DTC is present. Refer to
ENGINE
7 - 52
ENGINE COOLANT THERMOSTAT - 3.7L/4.7L (Continued)DR
1 - THERMOSTAT HOUSING 2 - THERMOSTAT LOCATION
Fig.26ThermostatandThermostatHousing3.7L/4.7L 3 - THERMOSTAT AND GASKET 4 - TIMING CHAIN COVER
ENGINE COOLANT THERMOSTAT - 5.9L DIESEL DESCRIPTION
CAUTION: Do not operate an engine without a ther- mostat, except for servicing or testing. An engine with the thermostat removed will operate in the radiator bypass mode, causing an overheat condi- tion.
The thermostat of the 5.9L diesel engine is located in the front of the cylinder head, underneath the thermostat housing (Fig. 27).
The same thermostat is used for winter and sum- mer seasons. An engine should not be operated with- out a thermostat, except for servicing or testing. Operating without a thermostat will cause overheat- ing.
OPERATION
The wax pellet is located in a sealed container at the spring end of the thermostat. When heated, the pellet expands, overcoming closing spring tension and water pump pressure to force the valve to open.
DIAGNOSIS AND TESTING—THERMOSTAT
The cooling system used with the diesel engine provides the extra coolant capacity and extra cooling
Fig.27Thermostat–5.9LDiesel-Typical
1 - THERMOSTAT HOUSING 2 - CYLINDER HEAD 3 - THERMOSTAT
protection needed for higher GVWR (Gross Vehicle Weight Rating) and GCWR (Gross Combined Weight Rating) vehicles.
DR ENGINE COOLANT THERMOSTAT - 5.9L DIESEL (Continued)
ENGINE
7 - 53
This system capacity will not effect warm up or cold weather operating characteristics if the thermo- stat is operating properly. This is because coolant will be held in the engine until it reaches the ther- mostat “set” temperature.
Diesel engines, due to their inherent efficiency are slower to warm up than gasoline powered engines, and will operate at lower temperatures when the vehicle is unloaded. Because of this, lower tempera- ture gauge readings for diesel versus gasoline engines may, at times be normal.
Typically, complaints of low engine coolant temper- ature are observed as low heater output when com- bined with cool or cold outside temperatures.
To help promote faster engine warm-up, the elec- tric engine block heater must be used with cool or cold outside temperatures. This will help keep the engine coolant warm when the vehicle is parked. Use the block heater if the outside temperature is below 4°C (40°F). Do not use the block heater if the outside temperature is above 4°C (40°F).
A “Cold Weather Cover” is available from the parts department through the Mopar Accessories product line. This accessory cover is designed to block airflow entering the radiator and engine compartment to promote faster engine warm-up. It attaches to the front of the vehicle at the grill opening. The cover is to be used with cool or cold temperatures only. If used with high outside temperatures, serious engine damage could result. Refer to the litera- ture supplied with the cover for additional informa- tion.
(1) To determine if the thermostat is defective, it must be removed from the vehicle (Refer to 7 - COOLING/ENGINE/ENGINE COOLANT THERMO- STAT - REMOVAL).
(2) After the thermostat has been removed, exam- ine the thermostat and inside of thermostat housing for contaminants. If contaminants are found, the thermostat may already be in a “stuck open” position. Flush the cooling system before replacing thermostat (Refer to 7 - COOLING - STANDARD PROCE- DURE).
(3) Place the thermostat into a container filled
the valve is still moving when the water temperature reaches 97°C (207°F), it is opening too late. Replace thermostat. If the valve refuses to move at any time, replace thermostat.
REMOVAL
WARNING: DO NOT LOOSEN THE RADIATOR DRAINCOCK WITH THE SYSTEM HOT AND PRES- SURIZED. SERIOUS BURNS FROM THE COOLANT CAN OCCUR.
Do not waste reusable coolant. If the solution is clean, drain the coolant into a clean container for reuse.
(1) Disconnect the battery negative cables. (2) Drain cooling system until coolant
is below thermostat (Refer to 7 - COOLING - STAN- DARD PROCEDURE).
level
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). SNAP-ON CLAMP TOOL (NUMBER HPC-20) MAY BE USED FOR LARGER CLAMPS. ALWAYS WEAR SAFETY GLASSES WHEN SERVICING CON- STANT TENSION CLAMPS.
CAUTION: A number or letter is stamped into the tongue of constant tension clamps. If replacement is necessary, use only an original equipment clamp with a matching number or letter.
(3) Remove radiator hose clamp and hose from
thermostat housing.
(4) Remove the three (3) water outlet-to-cylinder head bolts and remove the water outlet connector (Fig. 28).
(5) Clean the mating surfaces of the water outlet connector and clean the thermostat seat groove at the top of the thermostat housing (Fig. 28).
INSTALLATION
Replace if damaged.
with water.
able heating device.
(4) Place the container on a hot plate or other suit-
(1) Inspect
thermostat seal
for cuts or nicks.
(5) Place a commercially available radiator ther-
mometer into the water.
(6) Apply heat to the water while observing the
thermostat and thermometer.
(7) The thermostat will begin to open at 85.5 — 89.4°C. (186 —193°F ). If the valve starts to move before this temperature is reached, it is opening too early. Replace thermostat. The thermostat should be fully open (valve will stop moving) at 97°C (207°F). If
(2) Install the thermostat into the groove in the
top of the cylinder head (Fig. 28).
(3) Install
the thermostat housing and bolts.
Tighten the bolts to 10 N·m (88 in. lbs.) torque. (4) Install the radiator upper hose and clamp. (5) Fill the cooling system with coolant (Refer to 7
- COOLING - STANDARD PROCEDURE). (6) Connect the battery negative cables.
ENGINE
7 - 54
ENGINE COOLANT THERMOSTAT - 5.9L DIESEL (Continued)DR
Fig.28ThermostatRemoval/Installation
1 - THERMOSTAT HOUSING 2 - CYLINDER HEAD 3 - THERMOSTAT
(7) Start the engine and check for coolant leaks. Run engine to check for proper thermostat operation.
FAN DRIVE VISCOUS CLUTCH DESCRIPTION
The thermal viscous fan drive (Fig. 29) is a sili- cone-fluid- filled coupling used to connect the fan blades to the water pump shaft. The coupling allows the fan to be driven in a normal manner. This is done at low engine speeds while limiting the top speed of the fan to a predetermined maximum level at higher engine speeds.
OPERATION
A thermostatic bimetallic spring coil is located on the front face of the viscous fan drive unit (a typical viscous unit is shown in (Fig. 30). This spring coil reacts to the temperature of the radiator discharge air. It engages the viscous fan drive for higher fan speed if the air temperature from the radiator rises above a certain point. Until additional engine cooling is necessary, the fan will remain at a reduced rpm regardless of engine speed.
Only when sufficient heat is present, will the vis- cous fan drive engage. This is when the air flowing through the radiator core causes a reaction to the bimetallic coil. It then increases fan speed to provide the necessary additional engine cooling.
Fig.29ViscousFan
1 - WATER PUMP BYPASS HOSE 2 - FAN BLADE ASSEMBLY 3 - VISCOUS FAN DRIVE 4 - WATER PUMP AND PULLEY
Once the engine has cooled, the radiator discharge temperature will drop. The bimetallic coil again reacts and the fan speed is reduced to the previous disengaged speed.
Fig.30ViscousFanDrive—Typical
1 - VISCOUS FAN DRIVE 2 - THERMOSTATIC SPRING 3 - MOUNTING NUT TO WATER PUMP HUB
DIAGNOSIS AND TESTING - VISCOUS FAN DRIVE
NOISE
NOTE: It is normal for fan noise to be louder (roar- ing) when:
† The underhood temperature is above the engage- ment point for the viscous drive coupling. This may
DR FAN DRIVE VISCOUS CLUTCH (Continued)
occur when ambient (outside air temperature) is very high.† Engine loads and temperatures are high such as when towing a trailer. † Cool silicone fluid within the fan drive unit is being redistributed back to its normal disengaged (warm) position. This can occur during the first 15
seconds to one minute after engine start-up on a cold engine.LEAKS
Viscous fan drive operation is not affected by small oil stains near the drive bearing. If leakage appears excessive, replace the fan drive unit.
VISCOUS DRIVE
If the fan assembly free-wheels without drag (the fan blades will revolve more than five turns when spun by hand), replace the fan drive. This spin test must be performed when the engine is cool.
For the following test, the cooling system must be in good condition. It also will ensure against exces- sively high coolant temperature.
WARNING: BE SURE THAT THERE IS ADEQUATE FAN BLADE CLEARANCE BEFORE DRILLING.
(1) Drill a 3.18-mm (1/8-in) diameter hole in the
top center of the fan shroud.
(2) Obtain a dial thermometer with an 8 inch stem (or equivalent). It should have a range of -18°-to- 105°C (0°-to-220° F). Insert thermometer through the hole in the shroud. Be sure that there is adequate clearance from the fan blades.
(3) Connect a tachometer and an engine ignition timing light. The timing light is to be used as a strobe light. This step cannot be used on the diesel engine.
(4) Block the air flow through the radiator. Secure a sheet of plastic in front of the radiator. Use tape at the top to secure the plastic and be sure that the air flow is blocked.
(5) Be sure that the air conditioner (if equipped) is
turned off.
WARNING: USE EXTREME CAUTION WHEN THE ENGINE IS OPERATING. DO NOT STAND IN A DIRECT LINE WITH THE FAN. DO NOT PUT YOUR HANDS NEAR THE PULLEYS, BELTS OR FAN. DO NOT WEAR LOOSE CLOTHING.
(6) Start the engine and operate at 2400 rpm. Within ten minutes the air temperature (indicated on the dial thermometer) should be up to 88° C (190° F). Fan drive engagement should start to occur at/be- tween:† 3.7L Automatic — 93° C - 99°C (200° F - 210° F)
ENGINE
7 - 55
(185° to 195° F)
† 3.7L Manual/4.7L Automatic/5.9L — 85° to 91° C † 4.7L Manual — 74° to 79° C (165° to 175° F) † Engagement is distinguishable by a definite increase in fan flow noise (roaring). The timing light also will indicate an increase in the speed of the fan. (7) When viscous drive engagement is verified, remove the plastic sheet. Fan drive disengagement should start to occur at or between: † 3.7L Automatic — 76°C to 81°C (168° F to 178° F)† 3.7L Manual/4.7L Auto/ 5.9L — 67°C to 73°C (153° F to 163° F) † 4.7L Manual — 56°C to 62°C (133° F to 143° F) † 8.0L engine — 88° to 96° C (190° to 205° F) A definite decrease of fan flow noise (roaring) should be noticed. If not, replace the defective viscous fan drive unit.
CAUTION: Some engines equipped with serpentine drive belts have reverse rotating fans and viscous fan drives. They are marked with the word REVERSE to designate their usage. Installation of the wrong fan or viscous fan drive can result in engine overheating.
If
the viscous fan drive is replaced CAUTION: because of mechanical damage, the cooling fan blades should also be inspected. Inspect for fatigue cracks, loose blades, or loose rivets that could have resulted from excessive vibration. Replace fan blade assembly if any of these conditions are found. Also inspect water pump bearing and shaft assembly for any related damage due to a viscous fan drive malfunction.
FAN DRIVE VISCOUS CLUTCH - 5.9L DIESEL DESCRIPTION
The electronically controlled thermal viscous fan drive (Fig. 31) is attached to the fan drive pulley mounted to the engine. The coupling allows the fan to be driven in a normal manner. The fan speed is controlled by the electronic control module.
OPERATION
The Engine Control Module (ECM) controls the level of engagment of the electronically controlled viscous fan clutch by monitoring coolant tempera- ture, intake manifold temperature, and air condition- ing status. Based on cooling requirements, the ECM sends a signal to the viscous fan clutch to increase or decrease the fan speed.
ENGINE
7 - 56
FAN DRIVE VISCOUS CLUTCH - 5.9L DIESEL (Continued)DR
ELECTRONICALLY CONTROLLED VISCOUS DRIVE
If the fan assembly free-wheels without drag (the fan blades will revolve more than five turns when spun by hand), replace the fan drive. This spin test must be performed when the engine is cool.
For the following test, the cooling system must be in good condition. It also will ensure against exces- sively high coolant temperature.
The Electronic Viscous Fan drive can be tested
using the DRB III scan tool.
(1) Set the parking brake and verify the transmis-
sion is in park or neutral.
(2) Stat and allow engine to reach normal operat-
ing termeratures.
(3) With engine idling, connect the DRB III and
select appropraite model year and engine option.
(4) Lacate and select actuator tests, then select
PWM Viscous Fan.
(5) Monitor fan speed and duty cycle; verify that the fan speed increments are proportional to the duty cycle precentage during the actuation event.
Fig.31FanBlade/ViscousFanDrive
1 - ELECTRICAL CONNECTOR 2 - VISCOUS FAN DRIVE 3 - FAN BLADE 4 - BOLT 5 - FAN DRIVE
Fan speed is monitored by the ECM. A lack of fan speed will set a DTC. Circuit concerns will also set fan clutch DTC’s.
Fan speed and duty cycle percent can be monitored
with the DRB III..
DIAGNOSIS AND TESTING - ELECTRONICLY CONTOLLED VISCOUS FAN DRIVE
NOISE
NOTE: It is normal for fan noise to be louder (roar- ing) when:
when towing a trailer.
ent (outside air temperature) is very high.
† Fan duty cycle high. This may occur when ambi- † Engine loads and temperatures are high such as † Cool silicone fluid within the fan drive unit is being redistributed back to its normal disengaged (warm) position. This can occur during the first 15
seconds to one minute after engine start-up on a cold engine.LEAKS
Viscous fan drive operation is not affected by small oil stains near the drive bearing. If leakage appears excessive, replace the fan drive unit.
CAUTION: Some engines equipped with serpentine drive belts have reverse rotating fans and viscous fan drives. They are marked with the word REVERSE to designate their usage. Installation of the wrong fan or viscous fan drive can result in engine overheating.
If
the viscous fan drive is replaced CAUTION: because of mechanical damage, the cooling fan blades should also be inspected. Inspect for fatigue cracks, loose blades, or loose rivets that could have resulted from excessive vibration. Replace fan blade assembly if any of these conditions are found.
RADIATOR DESCRIPTION
The radiator is a aluminum cross-flow design with horizontal tubes through the radiator core and verti- cal plastic side tanks (Fig. 32).
This radiator does not contain an internal trans-
mission oil cooler
OPERATION
The radiator supplies sufficient heat transfer using the cooling fins interlaced between the horizontal tubes in the radiator core to cool the engine.
DR RADIATOR (Continued)
Fig.32Radiator—Typical
1 - SCREW 2 - SCREW 3 - LOWER MOUNT 4 - RADIATOR 5 - DRAINCOCK 6 -LOWER MOUNT
DIAGNOSIS AND TESTING—RADIATOR COOLANT FLOW
Use the following procedure to determine if coolant
is flowing through the cooling system.
(1) Idle engine until operating temperature is reached. If the upper radiator hose is warm to the touch, the thermostat is opening and coolant is flow- ing to the radiator.
WARNING: HOT, PRESSURIZED COOLANT CAN CAUSE INJURY BY SCALDING. USING A RAG TO COVER THE RADIATOR PRESSURE CAP, OPEN RADIATOR CAP SLOWLY TO THE FIRST STOP. THIS WILL ALLOW ANY BUILT-UP PRESSURE TO VENT TO THE RESERVE/OVERFLOW TANK. AFTER PRES- SURE BUILD-UP HAS BEEN RELEASED, REMOVE CAP FROM FILLER NECK.
(2) Drain a small amount of coolant from the radi- ator until the ends of the radiator tubes are visible through the filler neck. Idle the engine at normal operating temperature. If coolant is flowing past the exposed tubes, the coolant is circulating.
REMOVAL
(1) Disconnect battery negative cables.
ENGINE
7 - 57
WARNING: DO NOT REMOVE THE CYLINDER BLOCK DRAIN PLUGS OR LOOSEN THE RADIATOR DRAINCOCK WITH THE SYSTEM HOT AND UNDER PRESSURE. SERIOUS BURNS FROM THE COOL- ANT CAN OCCUR.
(2) Drain the cooling system (Refer to 7 - COOL-
ING - STANDARD PROCEDURE).
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. ALWAYS WEAR SAFETY GLASSES WHEN SERVICING CONSTANT TENSION CLAMPS.
CAUTION: A number or letter is stamped into the tongue of constant tension clamps. If replacement is necessary, use only an original equipment clamp with a matching number or letter and the correct width.
(3) Remove the hose clamps and hoses from radia-
tor.
(4) Remove the coolant reserve/overflow tank hose
from the radiator filler neck. coolant
(5) Remove
reserve/overflow tank (5.9L) or the coolant degas container(3.7L/4.7L) from the fan shroud (pull straight up). The tank slips into slots on the fan shroud.
the
(6) Unclip the power steering hoses from the fan
shroud.
(7) Disconnect
the windshield washer reservoir tank and remove the tank.
the electrical connectors at
(8) Remove the fan shroud mounting bolts and pull up and out of the radiator tank clips (Fig. 33). Posi- tion shroud rearward over the fan blades towards engine.
(9) Disconnect the transmission cooler lines from the transmission cooler, then plug the transmission lines and cooler to prevent leakage.
(10) Disconnect the power steering lines from the power steering cooler, then plug the power steering lines and cooler to prevent leakage.
(11) Remove the two radiator upper mounting
bolts (Fig. 34).
(12) Lift the radiator straight up and out of the engine compartment. Take care not to damage cool- ing fins or tubes on the radiator and oil coolers when removing.
ENGINE
7 - 58
RADIATOR (Continued)Fig.33FanShroud
1 - RADIATOR 2 - SCREWS 3 - FAN SHROUD 4 - SLIDE MOUNT
Fig.34Radiator
1 - SCREW 2 - SCREW 3 - LOWER MOUNT 4 - RADIATOR 5 - DRAINCOCK 6 -LOWER MOUNT
DR
NOTE: The radiator is equipped with one alignment dowel on the bottom of the outlet tank and one retaining bracket on the front side of the inlet tank. Both features have rubber insulators attached to them that must be present. The alignment dowel fits into a hole at the bottom of the front end sheet metal vertical support post and the support bracket rests on top of the lower radiator closure tube.
CLEANING
Clean radiator fins are necessary for good heat transfer. The radiator and oil cooler fins should be cleaned when an accumulation of debris has occurred. With the engine cold, apply cold water and compressed air to the back (engine side) of the radi- ator to flush the radiator and/or oil coolers of debris.
INSPECTION
Inspect the radiator side tanks for cracks, broken or missing fittings also inspect the joint where the tanks seam up to the radiator core for signs of leak- age and/or deteriorating seals.
Inspect radiator core for corroded, bent or missing cooling fins. Inspect the core for bent or damaged cooling tubes.
INSTALLATION
(1) Position the fan shroud over the fan blades
rearward towards engine.
(2) Install the rubber insulators to the lower radi- ator mounting features (alignment dowel and support bracket at the lower part of the radiator).
(3) Lower the radiator into position while guiding the alignment dowel into the vertical post bracket. Position and seat the lower radiator support bracket onto the lower radiator closure tube.
(4) Install
the upper radiator mounting bolts.
Tighten bolts to 8.5 N·m (75 in. lbs.).
(5) Connect the lower radiator hose and install the
clamp in the proper position.
(6) Connect the power steering hoses to the power
steering oil cooler and install the clamps.
(7) Connect the transmission oil cooler lines to the transmission oil cooler and install the secondary latches.
(8) Position the fan shroud into the mounting clips on the radiator tanks and secure with bolts. Tighten the bolts to 8.5 N·m (75 in. lbs.).
(9) Secure the power steering hoses into the clip
on the lower fan shroud.
(10) Install the windshield washer reservoir tank
and connect the hose and electrical connector.
(11) Install
reserve/overflow container hose(s) to radiator filler neck and secure properly with clamps.
coolant
DR RADIATOR (Continued)
(12) Install coolant reserve/overflow container or degas container to fan shroud and tighten the bolts to 8.5 N·m (75 in. lbs.). (13) Connect upper
radiator hose and install
clamp.
(14) Install battery negative cable. (15) Fill cooling system with coolant (Refer to 7 -
COOLING - STANDARD PROCEDURE).
(16) Operate the engine until
it reaches normal operating temperature. Check cooling system fluid levels.
RADIATOR - 5.9L DIESEL DESCRIPTION
The radiator is a aluminum cross-flow design with horizontal tubes through the radiator core and verti- cal plastic side tanks (Fig. 35).
This radiator does not contain an internal trans-
mission oil cooler
Fig.35Radiator—Typical
1 - SCREW 2 - SCREW 3 - LOWER MOUNT 4 - RADIATOR 5 - DRAINCOCK 6 -LOWER MOUNT
OPERATION
The radiator supplies sufficient heat transfer using the cooling fins interlaced between the horizontal tubes in the radiator core to cool the engine.
ENGINE
7 - 59
DIAGNOSIS AND TESTING—RADIATOR COOLANT FLOW
Use the following procedure to determine if coolant
is flowing through the cooling system.
(1) Idle engine until operating temperature is reached. If the upper radiator hose is warm to the touch, the thermostat is opening and coolant is flow- ing to the radiator.
WARNING: HOT, PRESSURIZED COOLANT CAN CAUSE INJURY BY SCALDING. USING A RAG TO COVER THE RADIATOR PRESSURE CAP, OPEN RADIATOR CAP SLOWLY TO THE FIRST STOP. THIS WILL ALLOW ANY BUILT-UP PRESSURE TO VENT TO THE RESERVE/OVERFLOW TANK. AFTER PRES- SURE BUILD-UP HAS BEEN RELEASED, REMOVE CAP FROM FILLER NECK.
(2) Drain a small amount of coolant from the radi- ator until the ends of the radiator tubes are visible through the filler neck. Idle the engine at normal operating temperature. If coolant is flowing past the exposed tubes, the coolant is circulating.
REMOVAL
(1) Disconnect both battery negative cables.
WARNING: DO NOT REMOVE THE CYLINDER BLOCK DRAIN PLUGS OR LOOSEN THE RADIATOR DRAINCOCK WITH THE SYSTEM HOT AND UNDER PRESSURE. SERIOUS BURNS FROM COOLANT CAN OCCUR.
(2) Drain the cooling system (Refer to 7 - COOL-
ING - STANDARD PROCEDURE).
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). SNAP-ON CLAMP TOOL (NUMBER HPC-20) MAY BE USED FOR LARGER CLAMPS. ALWAYS WEAR SAFETY GLASSES WHEN SERVICING CON- STANT TENSION CLAMPS.
CAUTION: A number or letter is stamped into the tongue of constant tension clamps. If replacement is necessary, use only an original equipment clamp with a matching number or letter.
(3) Remove air box and turbocharger inlet tube. (4) Remove coolant tank hose, washer bottle hose and the positive battery cable from the fastening clips located on top of the radiator.
(5) Remove hose clamps and hoses from radiator.
ENGINE
7 - 60
RADIATOR - 5.9L DIESEL (Continued)DR
(6) Remove the power steering cooler mounting bolts and position the power steering cooler out of the way.
(7) Disconnect the transmission cooler lines at the transmission. The transmission cooler will remain on the radiator and can be removed as an assembly.
(8) Remove the lower shroud assembly and the electronic viscous fan wiring from the upper shroud assembly.
(9) Remove the two radiator upper mounting bolts
(Fig. 36).
Fig.36FanShroudMounting—5.9LDieselEngine 1 - RADIATOR SUPPORT 2 - UPPER FAN SHROUD 3 - BOLTS (2) 4 - LOWER FAN SHROUD 5 - RADIATOR
(10) Lift radiator straight up and out of engine compartment. The bottom of the radiator is equipped with two alignment dowels that fit into holes in the lower radiator support panel. Rubber biscuits (insu- lators) are installed to these dowels. Take care not to damage cooling fins or tubes on the radiator and air conditioning condenser when removing.
CLEANING
Clean radiator fins are necessary for good heat transfer. The radiator and oil cooler fins should be cleaned when an accumulation of debris has occurred. With the engine cold, apply cold water and compressed air to the back (engine side) of the radi- ator to flush the radiator and/or oil coolers of debris.
INSPECTION
Inspect the radiator side tanks for cracks, broken or missing fittings also inspect the joint where the tanks seam up to the radiator core for signs of leak- age and/or deteriorating seals.
Inspect radiator core for corroded, bent or missing cooling fins. Inspect the core for bent or damaged cooling tubes.
INSTALLATION
(1) Install rubber insulators to alignment dowels
at lower part of radiator.
(2) Lower the radiator into position while guiding the two alignment dowels into lower radiator sup- port. Different alignment holes are provided in the lower radiator support for each engine application.
(3) Install
two upper radiator mounting bolts.
Tighten bolts to 11 N·m (95 in. lbs.) torque.
(4) Connect both radiator hoses and install hose
clamps.
(5) Connect transmission cooler lines to radiator tank. Inspect quick connect fittings for debris and install until an audible “click” is heard. Pull apart to verify connection.
(6) Position power steering cooler on the radiator
and tighten nuts to 8.5M·N (75 in. lbs.)
(7) Attach electronic viscous fan wiring to upper
shroud ands install lower shroud.
(8) Position coolant recover tank hose, washer bot- tle hose and the positive battery cable into the clips located on the top of the radiator.
(9) Install air box and turbocharger inlet hose.
Tighten clamps to 4 N·M (35 in. lbs.).
(10) Position heater controls to full heat position. (11) Fill cooling system with coolant (Refer to 7 -
COOLING - STANDARD PROCEDURE).
(12) Operate engine until it reaches normal tem- perature. Check cooling system and automatic trans- mission (if equipped) fluid levels.
RADIATOR PRESSURE CAP DESCRIPTION
All cooling systems are equipped with a pressure cap (Fig. 37). For 5.9L engines, the pressure cap is located on top of the radiator outlet tank. For the 3.7L/4.7L engines, the pressure cap is located on top of the coolant degas container. The cap releases pres- sure at some point within a range of 97-to-124 kPa (14-to-18 psi). The pressure relief point (in pounds) is engraved on top of the cap
The cooling system will operate at pressures slightly above atmospheric pressure. This results in a higher coolant boiling point allowing increased radi- ator cooling capacity. The cap contains a spring-
DR RADIATOR PRESSURE CAP (Continued)
loaded pressure relief valve. This valve opens when system pressure reaches the release range of 97-to- 124 kPa (14-to-18 psi).
A rubber gasket seals the radiator filler neck. This is done to maintain vacuum during coolant cool-down and to prevent leakage when system is under pres- sure.
ENGINE
7 - 61
DIAGNOSIS AND TESTING
DIAGNOSIS AND TESTING—RADIATOR CAP-TO-FILLER NECK SEAL
The pressure cap upper gasket (seal) pressure relief can be tested by removing overflow hose from the radiator filler neck tube. Attach the hose of the pressure tester tool 7700 (or equivalent) to the tube. It will be necessary to disconnect hose from its adapter for the filler neck. Pump air into radiator. The pressure cap upper gasket should relieve at 69
to 124kPa (10 to 18 psi) and hold pressure at a min- imum of 55 kPa (8 psi).WARNING: THE WARNING WORDS —DO NOT OPEN HOT— ON RADIATOR PRESSURE CAP, ARE A SAFETY PRECAUTION. WHEN HOT, PRESSURE BUILDS UP IN COOLING SYSTEM. TO PREVENT SCALDING OR INJURY, RADIATOR CAP SHOULD NOT BE REMOVED WHILE SYSTEM IS HOT AND/OR UNDER PRESSURE.
Do not remove the radiator cap at any time except
for the following purposes:
(1) Check and adjust antifreeze freeze point. (2) Refill the system with new antifreeze. (3) Conducting service procedures. (4) Checking for vacuum leaks.
Fig.37RadiatorPressureCap-Typical
1 - FILLER NECK SEAL 2 - VACUUM VENT VALVE 3 - PRESSURE RATING 4 - PRESSURE VALVE
OPERATION
A vent valve in the center of the cap will remain shut as long as the cooling system is pressurized. As the coolant cools, it contracts and creates a vacuum in the cooling system. This causes the vacuum valve to open and coolant in the reserve/overflow container to be drawn through the recovery hose connecting the filler neck and reserve/overflow container. If the vacuum valve is stuck shut, or the recovery hose is kinked, radiator hoses will collapse on cool down.
For the 3.7L/4.7L engine, the vacuum valve will open and relieve the vacuum pressure in the cooling system.
WARNING: IF VEHICLE HAS BEEN RUN RECENTLY, WAIT AT LEAST 15 MINUTES BEFORE REMOVING RADIATOR CAP. WITH A RAG, SQUEEZE RADIATOR UPPER HOSE TO CHECK IF SYSTEM IS UNDER PRESSURE. PLACE A RAG OVER CAP AND WITH- OUT PUSHING CAP DOWN, ROTATE IT COUNTER- CLOCKWISE TO FIRST STOP. ALLOW FLUID TO ESCAPE THROUGH THE COOLANT RESERVE/ OVERFLOW HOSE INTO RESERVE/OVERFLOW TANK. SQUEEZE RADIATOR UPPER HOSE TO DETERMINE WHEN BEEN RELEASED. WHEN COOLANT AND STEAM STOP BEING PUSHED INTO TANK AND SYSTEM PRES- SURE DROPS, REMOVE RADIATOR CAP COM- PLETELY.
PRESSURE
HAS
DIAGNOSIS AND TESTING - RADIATOR CAP
Remove the cap from the radiator. Be sure that the sealing surfaces are clean. Moisten the rubber gasket with water and install the cap on the pressure tester 7700 or an equivalent (Fig. 38).
Operate the tester pump to bring the pressure to 104 kPa (15 psi) on the gauge. If the pressure cap fails to hold pressure of at least 97 kPa (14 psi) replace the cap. Refer to the following CAUTION.
ENGINE
7 - 62
RADIATOR PRESSURE CAP (Continued)DR
Fig.39RadiatorPressureCap
1 - STAINLESS-STEEL SWIVEL TOP 2 - RUBBER SEALS 3 - VENT VALVE 4 - RADIATOR TANK 5 - FILLER NECK 6 - OVERFLOW NIPPLE 7 - MAIN SPRING 8 - GASKET RETAINER
designed for a coolant reserve/overflow system with a completely sealed diaphragm spring and a rubber gasket. This gasket is used to seal to radiator filler neck top surface. Use of proper cap will allow coolant return to radiator.
WATER PUMP - 5.9L DESCRIPTION
The water pump is located on the engine front cover, and has an integral pulley attached (Fig. 40). The water pump impeller is pressed onto the rear of a shaft that rotates in a bearing pressed into the water pump body. The body has a small hole for ven- tilation. The water pump seals are lubricated by antifreeze in the coolant mixture. Additional lubrica- tion is not necessary.
OPERATION
A centrifugal water pump circulates
coolant through the water jackets, passages, intake manifold, radiator core, cooling system hoses and heater core, this coolant absorbs the heat generated when the engine is running. The pump is driven by the engine crankshaft via a drive belt.
DIAGNOSIS AND TESTING—WATER PUMP
A quick test to determine if pump is working is to check if heater warms properly. A defective water pump will not be able to circulate heated coolant through the long heater hose to the heater core.
Fig.38PressureTestingRadiatorCap-Typical
1 - PRESSURE CAP 2 - TYPICAL COOLING SYSTEM PRESSURE TESTER
The pressure cap may test properly while posi- tioned on tool 7700 (or equivalent). It may not hold pressure or vacuum when installed on the radiator. If so, inspect the radiator filler neck and radiator cap’s top gasket for damage. Also inspect for dirt or distor- tion that may prevent the cap from sealing properly.
CAUTION: Radiator pressure testing tools are very sensitive to small air leaks which will not cause cooling system problems. A pressure cap that does not have a history of coolant loss should not be replaced just because it leaks slowly when tested with this tool. Add water to tool. Turn tool upside down and recheck pressure cap to confirm that cap needs replacement.
CLEANING
Use only a mild soap and water to clean the radi- ator cap. Using any type of solvent may cause dam- age to the seal in the radiator cap.
INSPECTION
Hold cap at eye level, right side up. The vent valve (Fig. 39) at bottom of cap should closed. A slight downward pull on the vent valve should open it. If the rubber gasket has swollen and prevents vent valve from opening, replace cap.
Hold cap at eye level, upside down. If any light can be seen between vent valve and rubber gasket, replace cap. A replacement cap must be the type
DR WATER PUMP - 5.9L (Continued)
ENGINE
7 - 63
Fig.40WaterPumpLocation—Typical
1 - WATER PUMP BYPASS HOSE 2 - FAN BLADE ASSEMBLY 3 - VISCOUS FAN DRIVE 4 - WATER PUMP AND PULLEY
REMOVAL
The water pump on all models can be removed without discharging the air conditioning system (if equipped).
The water pump on all gas powered engines is bolted directly to the engine timing chain case/cover. On the 5.9L gas powered engine, a gasket is used as a seal between the water pump and timing chain case/cover.
If water pump is replaced because of bearing/shaft damage or leaking shaft seal, the mechanical cooling fan assembly should also be inspected. Inspect for fatigue cracks, loose blades or loose rivets that could have resulted from excessive vibration. Replace fan if any of these conditions are found. Also check condi- tion of the thermal viscous fan drive (Refer to 7 - COOLING/ENGINE/FAN VISCOUS CLUTCH - DIAGNOSIS AND TESTING).
DRIVE
(1) Disconnect the negative cable. (2) Drain cooling system (Refer to 7 - COOLING -
STANDARD PROCEDURE).
Do not waste reusable coolant. If solution is clean,
drain coolant into a clean container for reuse.
(3) Remove the radiator fan (Refer to 7 - COOL-
ING/ENGINE/RADIATOR FAN - REMOVAL)
(4) Remove accessory drive belt
(Refer to 7 - COOLING/ACCESSORY DRIVE/DRIVE BELTS - REMOVAL) (Fig. 41).
(5) Remove the lower radiator hose and heater
hose from the water pump.
(6) Loosen the heater hose coolant return tube mounting bolt (Fig. 42) and remove the tube from the water pump. Discard the old tube O-ring.
(7) Remove the water pump mounting bolts (Fig.
43).
Fig.41BeltTensioner5.9LV-8Engine
1 - IDLER PULLEY 2 - TENSIONER 3 - FAN BLADE
Fig.42CoolantReturnTube5.9L
1 - COOLANT RETURN TUBE 2 - WATER PUMP 3 - TUBE MOUNTING BOLT 4 - O-RING
(8) Loosen the clamp at the water pump end of bypass hose (Fig. 42). Slip the bypass hose from the
ENGINE
7 - 64
WATER PUMP - 5.9L (Continued)DR
(6) Install the coolant return tube and its mount- ing bolt to the engine (Fig. 42). Be sure the slot in the tube bracket is bottomed to mounting bolt. This will properly position return tube.
(7) Connect the radiator lower hose to the water
pump.
(8) Connect the heater hose and hose clamp to the
coolant return tube.
(9) Install drive belt (Refer to 7 - COOLING/AC- CESSORY DRIVE/DRIVE BELTS - INSTALLATION) (Fig. 41).
(10) Install the fan (Refer to 7 - COOLING/EN-
GINE/RADIATOR FAN - INSTALLATION)
(11) Fill cooling system (Refer to 7 - COOLING -
STANDARD PROCEDURE).
(12) Connect negative battery cable. (13) Start and warm the engine. Check for leaks.
WATER PUMP - 3.7L/4.7L
DESCRIPTION
DESCRIPTION—WATER 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. 44).
DESCRIPTION—WATER PUMP BYPASS
The 3.7L and 4.7L engine uses an internal water/ coolant bypass system. The design uses galleries in the timing 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. 45) to control flow through the bypass gallery.
OPERATION
OPERATION—WATER PUMP
A centrifugal water pump circulates
coolant through the water jackets, passages, intake manifold,
Fig.43WaterPumpBolts-5.9LV-8GasEngine-
Typical 1 - WATER PUMP MOUNTING BOLTS
water pump while removing pump from vehicle. Do not remove the clamp from the bypass hose.
(9) Discard the old gasket.
CAUTION: Do not pry the water pump at timing chain case/cover. The machined surfaces may be damaged resulting in leaks.
CLEANING
Clean gasket mating surfaces as necessary.
INSPECTION
Visually inspect the water pump and replace if it has any of the following conditions: † The body is cracked or damaged † Water leaks from the shaft seal. This is evident by traces of coolant below the vent hole † Loose or rough turning bearing. † Impeller rubbing the pump body INSTALLATION
(1) Clean the gasket mating surfaces. (2) Using a new gasket, install the water pump to the engine as follows: Guide the water pump tube into the bypass hose as the pump is being installed. Install the water pump bolts (Fig. 43). Tighten the water pump mounting bolts to 40 N·m (30 ft. lbs.) torque.
(3) Position the bypass hose clamp to the bypass
hose.
(4) Spin the water pump to be sure that the pump impeller does not rub against the timing chain case/ cover.
(5) Install a new o-ring to the heater hose coolant return tube (Fig. 42). Coat the new o-ring with anti- freeze before installation.
DR WATER PUMP - 3.7L/4.7L (Continued)
ENGINE
7 - 65
Fig.44WaterPumpandTimingChainCover
1 - INTEGRAL WATER PUMP PULLEY 2 - TIMING CHAIN COVER 3 - THERMOSTAT HOUSING 4 - HEATER HOSE FITTINGS 5 - WATER PUMP
radiator core, cooling system hoses and heater core, this coolant absorbs the heat generated when the engine is running. The pump is driven by the engine crankshaft via a drive belt.
OPERATION—WATER PUMP BYPASS
When the thermostat is in the closed position the bypass gallery is not obstructed allowing 100% flow. When the thermostat is in the open position the stub shaft enters the bypass gallery obstructing bypass coolant flow by 50%. This design allows the coolant to reach operating temperature quickly when cold, while adding extra cooling during normal tempera- ture operation.
REMOVAL
The water pump on 3.7L/4.7L engines is bolted
directly to the engine timing chain case cover.
(1) Disconnect the negative battery cable. (2) Drain cooling system (Refer to 7 - COOLING -
STANDARD PROCEDURE).
(3) Remove fan/viscous fan drive assembly from water pump (Fig. 46) (Refer to 7 - COOLING/EN- GINE/FAN DRIVE VISCOUS CLUTCH - REMOV- AL). Do not attempt to remove fan/viscous fan drive assembly from vehicle at this time.
WARNING: CONSTANT TENSION HOSE CLAMPS ARE USED ON MOST COOLING SYSTEM HOSES.
Fig.45Water/CoolantBypassFlowandThermostat 1 - FROM HEATER AND DEGAS CONTAINER 2 - FROM RADIATOR 3 - TO WATER PUMP 4 - ENGINE BYPASS 5 - THERMOSTAT
WHEN REMOVING OR INSTALLING, USE ONLY TOOLS DESIGNED FOR SERVICING THIS TYPE OF CLAMP. ALWAYS WEAR SAFETY GLASSES WHEN SERVICING CONSTANT TENSION CLAMPS.
CAUTION: A number or letter is stamped into the tongue of constant tension clamps. If replacement is necessary, use only an original equipment clamp with matching number or letter and width.
(4) If the water pump is being replaced, do not unbolt the fan blade assembly from the thermal vis- cous fan drive.
(5) Remove the radiator fan (Refer to 7 - COOL-
ING/ENGINE/RADIATOR FAN - REMOVAL).
(6) Remove accessory drive belt (Fig. 47) (Refer to 7 - COOLING/ACCESSORY DRIVE/DRIVE BELTS - REMOVAL).
(7) Remove the lower radiator hose clamp and
remove the lower hose at the water pump.
(8) Remove the water pump mounting bolts.
ENGINE
7 - 66
WATER PUMP - 3.7L/4.7L (Continued)DR
(9) Remove the water pump and gasket. Discard
gasket.
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, worn bearing or impeller rubbing either the pump body or timing chain case/cover.
INSTALLATION
The water pump on 3.7L/4.7L engine is bolted
directly to the engine timing chain case cover.
(1) Clean the gasket mating surfaces. (2) Using a new gasket, position water pump and (Fig. 48). Tighten the
install the mounting bolts. water pump mounting bolts to 58 N·m (43 ft. lbs.).
Fig.46ViscousFanandFanDrive4.7LEngine 1 - SPECIAL TOOL 6958 SPANNER WRENCH WITH ADAPTER PINS 8346
2 - FANFig.47AutomaticBeltTensioner—4.7L
1 - AUTOMATIC TENSIONER 2 - WATER PUMP PULLEY
CAUTION: Do not pry water pump at timing chain case/cover. The machined surfaces may be dam- aged resulting in leaks.
Fig.48WaterPumpInstallation—3.7L/4.7LTypical 1 - WATER PUMP 2 - TIMING CHAIN COVER
(3) Spin the water pump to be sure that the pump impeller does not rub against the timing chain case/ cover.
(4) Connect the radiator lower hose to the water
pump.
(5) Relax the tension from the belt tensioner (Fig. 47). Install the drive belt (Refer to 7 - COOLING/AC- CESSORY DRIVE/DRIVE BELTS - INSTALLA- TION).
DR WATER PUMP - 3.7L/4.7L (Continued)
CAUTION: When installing the 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 (Fig. 49) for the correct belt routing. Or, refer to the Belt Routing Label located in the engine compartment. The cor- rect belt with correct length must be used.
ENGINE
7 - 67
antifreeze in the coolant mixture. Additional lubrica- tion is not necessary.
OPERATION
The diesel engine water pump draws coolant from radiator outlet and circulates it through engine, heater core and back to radiator inlet. The crank- shaft pulley drives the water pump with a serpentine drive belt.
DIAGNOSIS AND TESTING—WATER PUMP
A quick test to determine if pump is working is to check if heater warms properly. A defective water pump will not be able to circulate heated coolant through the long heater hose to the heater core.
REMOVAL
(1) Disconnect battery negative cables. (2) Drain cooling system (Refer to 7 - COOLING -
STANDARD PROCEDURE).
(3) Remove the accessory drive belt (Refer to 7 - COOLING/ACCESSORY DRIVE/DRIVE BELTS - REMOVAL).
(4) Remove water pump mounting bolts (Fig. 50).
Fig.49BeltRouting3.7L
1 - GENERATOR PULLEY 2 - ACCESSORY DRIVE BELT 3 - POWER STEERING PUMP PULLEY 4 - CRANKSHAFT PULLEY 5 - IDLER PULLEY 6 - TENSIONER 7 - A/C COMPRESSOR PULLEY 8 - WATER PUMP PULLEY
(6) Install the radiator fan (Refer to 7 - COOLING/
ENGINE/RADIATOR FAN - INSTALLATION).
(7) Fill cooling system (Refer to 7 - COOLING -
STANDARD PROCEDURE).
(8) Connect the negative battery cable. (9) Start and warm the engine. Check for leaks.
WATER PUMP - 5.9L DIESEL DESCRIPTION
The water pump is mounted to the front of the engine block between the automatic belt tensioner and the fan drive pulley.
The water pump impeller is pressed onto the rear of a shaft that rotates in a bearing pressed into the water pump body. The body has a small hole for ven- tilation. The water pump seals are lubricated by
Fig.50WaterPumpRemoval/Installation
1 - O-RING SEAL (SQUARE) 2 - WATER PUMP 3 - BOLT (2)
(5) Clean water pump sealing surface on cylinder
block.
CLEANING
Clean gasket mating surfaces as necessary.
DR
generator or A/C compressor from their mounting bracket is not necessary. Also, discharging the A/C system is not necessary. Do not remove any refriger- ant lines from A/C compressor.
ENGINE
7 - 68
WATER PUMP - 5.9L DIESEL (Continued) INSPECTIONVisually inspect the water pump and replace if it has any of the following conditions: † The body is cracked or damaged † Water leaks from the shaft seal. This is evident by traces of coolant below the vent hole † Loose or rough turning bearing. † Impeller rubbing the pump body INSTALLATION
(1) Install new O-ring seal
pump (Fig. 51).
in groove on water
Fig.51PumpO-ringSeal
1 - O-RING SEAL 2 - GROOVE 3 - WATER PUMP
Fig.52Generator-A/CCompressorMounting
Bracket-Typical
WARNING: THE A/C SYSTEM IS UNDER PRESSURE EVEN WITH THE ENGINE OFF. REFER TO REFRIG- ERANT WARNINGS IN SECTION 24 - HEATING AND AIR CONDITIONING.
(2) Install water pump. Tighten mounting bolts to
24 N·m (18 ft. lbs.) torque.
(3) Install accessory drive belt. Refer to procedure
in this group.
(4) Install the bolt retaining the wiring harness
near top of water pump.
System in this section.
(5) Fill cooling system. Refer to Refilling Cooling
(6) Connect both battery cables. (7) Start and warm the engine. Check for leaks.
WATER PUMP INLET TUBE - 5.9L
REMOVAL
REMOVAL - WATER PUMP BYPASS HOSE WITH AIR CONDITIONING
If equipped with A/C, the generator and A/C com- pressor along with their common mounting bracket (Fig. 52) must be partially removed. Removing the
(1) Disconnect the negative battery cable. (2) Partially drain the cooling system (Refer to 7 - COOLING - STANDARD PROCEDURE).Do not waste reusable coolant. If the solution is clean, drain the coolant into a clean container for reuse.
(3) Remove the upper radiator hose clamp at the radiator. A special clamp tool must be used to remove the constant tension clamps. Removethe hose at the radiator.
(4) Unplug the wiring harness from the A/C com-
pressor.
(5) Remove the air cleaner assembly. (6) Remove the accessory drive belt (Refer to 7 - COOLING/ACCESSORY DRIVE/DRIVE BELTS - REMOVAL).
(7) The drive belt idler pulley must be removed to gain access to one of the A/C compressor/generator bracket mounting bolts. Remove the idler pulley bolt and remove idler pulley (Fig. 53).
(8) Remove the engine oil dipstick tube mounting the A/C-generator mounting
the side of
bolt at bracket.
(9) Disconnect the throttle body control cables.
DR WATER PUMP INLET TUBE - 5.9L (Continued)
ENGINE
7 - 69
(12) Remove the remaining bracket-to-engine bolts
(Fig. 55).
Fig.53IdlerPulley-5.9LV-8GasEngine
(10) Remove the heater hose coolant return tube mounting bolt (Fig. 54) (Fig. 55) and remove the tube from the engine. Discard the old tube O-ring.
Fig.55BracketBolts-5.9LV-8Gas
1 - COOLANT TUBE MOUNTING BOLT 2 - BRACKET MOUNTING BOLTS
(13) Lift and position the generator and A/C com- pressor (along with their common mounting bracket) to gain access to the bypass hose. A block of wood may be used to hold the assembly in position.
(14) Loosen and position both hose clamps to the center of the bypass hose. A special clamp tool must be used to remove the constant tension clamps. Remove the hose from the vehicle.
REMOVAL - WATER PUMP BYPASS HOSE WITHOUT AIR CONDITIONING
A water pump bypass hose (Fig. 56)
is used between the intake manifold and water pump on all gas powered engines. To test for leaks, (Refer to 7 - COOLING - DIAGNOSIS AND TESTING).
(1) Partially drain the cooling system (Refer to 7 - COOLING - STANDARD PROCEDURE). Do not waste reusable coolant. If the solution is clean, drain the coolant into a clean container for reuse.
Fig.54CoolantReturn
1 - COOLANT RETURN TUBE 2 - WATER PUMP 3 - TUBE MOUNTING BOLT 4 - O-RING
(11) Remove the bracket-to-intake manifold bolts
(number 1 and 2 (Fig. 52).
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. ALWAYS WEAR SAFETY GLASSES WHEN SERVICING CONSTANT TENSION CLAMPS.
ENGINE
7 - 70
WATER PUMP INLET TUBE - 5.9L (Continued)DR
Fig.56WaterPumpBypassHose-Typical
1 - WATER PUMP BYPASS HOSE 2 - FAN BLADE ASSEMBLY 3 - VISCOUS FAN DRIVE 4 - WATER PUMP AND PULLEY
CAUTION: A number or letter is stamped into the tongue of the constant tension clamps. If replace- ment is necessary, use only an original equipment clamp with a matching number or letter and width.
(2) Loosen both of the bypass hose clamps and
position them to the center of the hose. (3) Removethe hose from the vehicle.
INSTALLATION
INSTALLATION - WATER PUMP BYPASS HOSE WITH AIR CONDITIONING
(1) Position the bypass hose clamps to the center
of the bypass hose.
(2) Install the bypass hose to the engine. (3) Secure both of the hose clamps. (4) Install
the generator-A/C mounting bracket assembly to the engine. Tighten bolt number 1 (Fig. 53) to 41 N·m (30 ft. lbs.). Tighten bolt number 2
(Fig. 53) to 28 N·m (20 ft. lbs.). Tighten bracket mounting bolts (Fig. 53) (Fig. 53) to 40 N·m (30 ft. lbs.).(5) Install a new O-ring to the heater hose coolant return tube. Coat the new O-ring with antifreeze before installation.
(6) Install the coolant return tube and its mount-
ing bolt to the engine.
(7) Connect the throttle body control cables. (8) Install the oil dipstick mounting bolt. (9)
Install the idler pulley. Tighten the bolt to 41
N·m (30 ft. lbs.) (Fig. 57).
(10) Install the drive belt (Refer to 7 - COOLING/ ACCESSORY DRIVE/DRIVE BELTS - INSTALLA- TION).
Fig.57TensionerMounting
1 - DOWEL PIN HOLE 2 - TENSIONER MOUNTING BRACKET
CAUTION: When installing the 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 - INSTALLA- TION). The correct belt with the correct length must be used.
(11) Install the air cleaner assembly. (12) Install the upper radiator hose to the radiator. (13) Connect the throttle cable to the clip at the
radiator fan shroud.
pressor.
(14) Connect the wiring harness to the A/C com-
(15) Fill the cooling system (Refer to 7 - COOLING
- STANDARD PROCEDURE).
(16) Start and warm the engine. Check for leaks.
INSTALLATION - WATER PUMP BYPASS HOSE WITHOUT AIR CONDITIONING
(1) Position the bypass hose clamps to the center
of the bypass hose.
(2) Install the bypass hose tothe engine. (3) Secure both of the hose clamps. (4) Fill the cooling system (Refer to 7 - COOLING
- STANDARD PROCEDURE).
(5) Start and warm the engine. Check for leaks.
WATER PUMP - 5.7L REMOVAL
(1) Disconnect negative battery cable. (2) Drain coolant. (3) Remove serpentine belt. (4) Remove fan clutch assembly. (5) Remove coolant fill bottle.
DR WATER PUMP - 5.7L (Continued)
(6) Disconnect washer bottle wiring and hose. (7) Remove fan shroud assembly. (8) Remove A/C compressor and genterator brace. (9) Remove idler pulleys. (10) Remove belt tensioner assembly. (11) Remove upper and lower radiator hoses. (12) Remove heater hoses. (13) Remove water pump mounting bolts and
remove pump.
ENGINE
7 - 71
INSTALLATION
(1) Install water pump and mounting bolts.
Tighten moubting bolts to 24 N·m (18 ft. lbs.).
(2) Install heater hoses. (3) Install upper and lower radiator hoses. (4) Install belt tensioner assembly. (5) Install idler pulleys. (6) Install A/C compressor and alternator brace.
Tighten bolt and nuts to 28 N·m (21 ft. lbs.).
(7) Install fan shroud assembly. (8) Connect washer bottle wiring and hose. (9) Install coolant fill bottle. (10) Install fan clutch assembly. (11) Install serpentine belt. (12) Connect negative battery cable. (13) Fill coolant. (14) Pressure test coolant system
7 - 72
TRANSMISSION
TRANSMISSION
TABLE OF CONTENTS
page
DR
page
TRANS COOLER DESCRIPTION
DESCRIPTION . . . . . . . . . . . . . . . . . . . . . . . . 72
DESCRIPTION . . . . . . . . . . . . . . . . . . . . . . . . 72
OPERATION . . . . . . . . . . . . . . . . . . . . . . . . . . . 72
REMOVAL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 72
DISASSEMBLY - 5.9L ONLY . . . . . . . . . . . . . . . 73
ASSEMBLY - 5.9L ONLY . . . . . . . . . . . . . . . . . . 73
INSTALLATION . . . . . . . . . . . . . . . . . . . . . . . . . 73TRANS COOLER - 5.9L DIESEL
DESCRIPTION . . . . . . . . . . . . . . . . . . . . . . . . . 73
OPERATION . . . . . . . . . . . . . . . . . . . . . . . . . . . 74
REMOVALREMOVAL—AIR TO OIL COOLER . . . . . . . . . 74
REMOVAL—WATER TO OIL COOLER . . . . . . 74INSTALLATION
INSTALLATION—AIR TO OIL COOLER INSTALLATION
. . . . . 75
. . . . . . . . . . . . . . . . . . . . . . . 75TRANS COOLER
DESCRIPTION
DESCRIPTION
An air-to-oil transmission oil cooler is standard on all engine packages. The transmission oil cooler is mounted to the front of the radiator above the power steering cooler (Fig. 1).
DESCRIPTION
An air-to-oil transmission oil cooler is standard on all engine packages. The transmission oil cooler is mounted to the front of the radiator above the power steering cooler (Fig. 2).
OPERATION
to
the
returning
Transmission oil
is routed through the cooler where heat is removed from the transmission oil before transmission. Vehicles equipped with the 5.9L engine have an internal ther- mostat that controls fluid flow through the cooler- .When the transmission fluid is cold ( less than operating temperature) the fluid is routed through the cooler bypass. when the transmission fluid reaches operating temperatures and above, the ther- mostat closes off the bypass allowing fluid flow through the cooler. The thermostat is serviceable.
NOTE: Vehicles with the 3.7L/4.7L engines are not equipped with the oil cooler thermostat.
REMOVAL
(1) Disconnect the battery negative cable. (2) Place a drain pan under the oil cooler lines.
Fig.1CoolingModule—5.9LGas
1 - TRANS OIL COOLER BYPASS (5.9L only) 2 - OIL COOLER THERMOSTATIC BYPASS VALVE (5.9L only) 3 -TRANS OIL COOLER 4 - OIL COOLER MOUNTING BOLT (4) 5 - POWER STEERING COOLER 6 - POWER STEERING COOLER MOUNTING BOLT(2) 7 - TRANS OIL COOLER OUTLET 8 - TRANS OIL COOLER INLET 9 - COOLER LINE CLIP 10 - COOLER LINE CLIP 11 - RADIATOR
(3) Disconnect
the transmission oil cooler line quick-connect fitting at the cooler outlet using the quick connect release tool 6935. Plug the cooler lines to prevent oil leakage.
(4) Unsnap the transmission cooler tubes from the
radiator tank clips.
DR TRANS COOLER (Continued)
TRANSMISSION
7 - 73
Fig.3TransmissionOilCoolerThermostat
Removal/Installation
1 - THERMOSTAT HOUSING 2 - SPRING 3 - END PLUG 4 - SNAP RING 5 - THERMOSTAT
Fig.2CoolingModule-3.7L/4.7L/5.7L
1 - TRANS OIL COOLER 2 - TRANS OIL COOLER MOUNTING BOLT (3) 3 - POWER STEERING OIL COOLER 4 - POWER STEERING OIL COOLER MOUNTING BOLT 5 - TRANS OIL COOLER OUTLET 6 - TRANS OIL COOLER INLET 7 - COOLER LINE CLIP 8 - COOLER LINE CLIP 9 - RADIATOR
(5) Remove the bolts attaching the transmission
cooler to the radiator.
(6) Remove oil cooler from the vehicle. Take care not to damage the radiator core or transmission cooler tubes.
DISASSEMBLY - 5.9L ONLY
NOTE: The transmission oil cooler uses an internal thermostat to control transmission oil flow through the cooler. This thermostat is servicable.
(1) Remove the transmission oil cooler (Refer to 7 -
COOLING/TRANSMISSION/TRANS REMOVAL).
COOLER
(2) Remove the snap ring retaining the thermostat
end plug (Fig. 3).
(3) Remove the end plug, thermostat and spring
from transmission oil cooler (Fig. 3).
ASSEMBLY - 5.9L ONLY
(1) Throughly clean the thermostat bore on the
transmission oil cooler.
and snap ring.
(2) Install the new spring, thermostat, end plug
(3) Install the transmission oil cooler (Refer to 7 -
COOLING/TRANSMISSION/TRANS INSTALLATION).
COOLER
INSTALLATION
(1) Position the transmission cooler tubes to the
front of the radiator.
(2) Snap the transmission cooler tubes into the
clips on the side of the radiator tank.
(3) Install the transmission cooler attaching bolts.
Tighten the bolts to 16 N·m (140 in. lbs.).
(4) inspect the quick connect fittings for debris and install the quick connect fitting on the cooler tube until an audible “click” is heard. Pull apart the con- nection to verify proper installation and install the secondary latches.
(5) Connect the battery negative cable. (6) Start the engine and check all
fittings for
leaks.
(7) Check the fluid level in the automatic trans- mission. Refer to the appropriate transmission sec- tion(Refer to 21 - TRANSMISSION/TRANSAXLE/ AUTOMATIC - 45RFE/545RFE/FLUID - STANDARD PROCEDURE) or(Refer to 21 - TRANSMISSION/ TRANSAXLE/AUTOMATIC - 46RE/FLUID - STAN- DARD PROCEDURE).
TRANS COOLER - 5.9L DIESEL DESCRIPTION
All diesel models equipped with an automatic transmission are equipped with both a main water- to-oil cooler and a separate air-to-oil cooler. Both cool-
TRANSMISSION
7 - 74
TRANS COOLER - 5.9L DIESEL (Continued)DR
ers are supplied as standard equipment on diesel engine powered models when equipped with an auto- matic transmission.
