
(4) Install water pump to engine as follows: Guide
water pump fitting into bypass hose as pump is being
installed. Install water pump bolts (Fig. 57). Tighten
water pump mounting bolts to 40 N´m (30 ft. lbs.)
torque.
(5) Position bypass hose clamp to bypass hose.
(6) Spin water pump to be sure that pump impel-
ler does not rub against timing chain case/cover.
(7) Connect radiator lower hose to water pump.
(8) Connect heater hose and hose clamp to heater
hose fitting.
(9) Install drive belt (Refer to 7 - COOLING/AC-
CESSORY DRIVE/DRIVE BELTS - INSTALLATION)
(Fig. 56).
(10) Position fan shroud and fan blade/viscous fan
drive assembly to vehicle as a complete unit.
(11) Install fan shroud to radiator. Tighten bolts to
6 N´m (50 in. lbs.) torque.
(12) Install fan blade/viscous fan drive assembly to
water pump shaft.
(13) Fill cooling system (Refer to 7 - COOLING -
STANDARD PROCEDURE).
(14) Connect negative battery cable.
(15) Start and warm the engine. Check for leaks.
WATER PUMP - 5.9L DIESEL
DESCRIPTION
The water pump is mounted to the engine front
cover between the automatic belt tensioner and the
fan drive pulley (Fig. 60).
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
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 (Fig. 60).
DIAGNOSIS AND TESTINGÐWATER 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 bolt retaining the wiring harness
near the top of water pump. Position wire harness to
the side.
(4) Remove the accessory drive belt (Refer to 7 -
COOLING/ACCESSORY DRIVE/DRIVE BELTS -
REMOVAL).
(5) Remove water pump mounting bolts (Fig. 61).
(6) Clean water pump sealing surface on cylinder
block.
CLEANING
Clean gasket mating surfaces as necessary.
INSPECTION
Visually inspect the water pump and replace if it
has any of the following conditions:
²The body is cracked or damaged
²Water leaks from the shaft seal. This is evident
by traces of coolant below the vent hole
²Loose or rough turning bearing. Also inspect
thermal fan drive
²Impeller rubbing the pump body
INSTALLATION
(1) Install new O-ring seal in groove on water
pump (Fig. 62).
(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.
Fig. 60 Water PumpÐ5.9L DieselÐTypical (non-A/C
shown)
1 - WATER PUMP
2 - ACCESSORY DRIVE BELT
3 - AUTOMATIC BELT TENSIONER
4 - MOUNT BOLT
5 - 3/89SQUARE HOLE
7 - 72 ENGINEBR/BE
WATER PUMP - 8.0L (Continued)

(4) Install the bolt retaining the wiring harness
near top of water pump.
(5) Fill cooling system. Refer to Refilling Cooling
System in this section.
(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. 63) must be partially removed. Removing the
generator or A/C compressor from their mounting
bracket is not necessary. Also, discharging the A/C
system is not necessary.Do notremove any refriger-
ant lines from A/C compressor.
WARNING: THE A/C SYSTEM IS UNDER PRESSURE
EVEN WITH THE ENGINE OFF. REFER TO REFRIG-
ERANT WARNINGS IN 24 - HEATING AND AIR CON-
DITIONING.
Fig. 61 Water Pump Removal/Installation
1 - O-RING SEAL (SQUARE)
2 - WATER PUMP
3 - BOLT (2)
Fig. 62 Pump O-ring Seal
1 - O-RING SEAL
2 - GROOVE
3 - WATER PUMP
Fig. 63 Generator - A/C Compressor Mounting
Bracket - Typical
BR/BEENGINE 7 - 73
WATER PUMP - 5.9L DIESEL (Continued)

(10)5.9L HDC-Gas:Install automatic belt ten-
sioner assembly to mounting bracket. A dowel pin is
located on back of tensioner (Fig. 71). Align this to
dowel hole (Fig. 72) in tensioner mounting bracket.
Tighten bolt to 41 N´m (30 ft. lbs.) torque.(11) Install drive belt (Refer to 7 - COOLING/AC-
CESSORY DRIVE/DRIVE BELTS - INSTALLA-
TION).
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.
(12) Install air cleaner assembly.
(13) Install upper radiator hose to radiator.
(14) Connect throttle cable to clip at radiator fan
shroud.
(15) Connect wiring harness to A/C compressor.
(16) Fill cooling system (Refer to 7 - COOLING -
STANDARD PROCEDURE).
(17) Start and warm the engine. Check for leaks.
INSTALLATION - WATER PUMP BYPASS HOSE
WITHOUT AIR CONDITIONING
(1) Position bypass hose clamps to the center of
hose.
(2) Install bypass hose to engine.
(3) Secure both hose clamps.
(4) Fill cooling system (Refer to 7 - COOLING -
STANDARD PROCEDURE).
(5) Start and warm the engine. Check for leaks.
Fig. 71 Tensioner Dowel Pin - 5.9L HDC-Gas Engine
1 - BELT TENSIONER
2 - DOWEL PIN
Fig. 72 Tensioner Mounting
1 - DOWEL PIN HOLE
2 - TENSIONER MOUNTING BRACKET
BR/BEENGINE 7 - 77
WATER PUMP INLET TUBE - 5.9L (Continued)

(3) Remove the end plug, thermostat and spring
from transmission oil cooler (Fig. 3).
ASSEMBLY
(1) Throughly clean the thermostat bore on the
transmission oil cooler.
(2) Install new spring, thermostat, end plug and
snap ring.
(3) Install transmission oil cooler (Refer to 7 -
COOLING/TRANSMISSION/TRANS COOLER -
INSTALLATION).
INSTALLATION
(1) Install the oil cooler assembly to the A-shaped
radiator support bracket using the two upper mount-
ing bolts and mounting straps. Install the bolts but
do not tighten at this time.
(2) Install the radiator support bracket and oil
cooler (as an assembly) to the vehicle.
(3) Install the two lower radiator A-shaped support
bracket bolts. Do not tighten bolts at this time.
(4) Slide and position the oil cooler on the
A-shaped bracket until its lower mounting hole lines
up with the bolt hole on the vehicle body. Tighten the
oil cooler mounting strap bolts to 6 N´m (50 in. lbs.)
torque.
(5) Install the upper radiator A-shaped support
bracket bolt. Tighten all three radiator support
bracket mounting bolts to 11 N´m (95 in. lbs.) torque.
(6) Inspect quick connect fitting for debris and
install the quick-connect fitting on the cooler outler
tube until an audible ªclickº is heard. Pull apart to
verify connection.
(7) Connect battery negative cable.
(8) Start the engine and check all fittings for
leaks.
(9) Check the fluid level in the automatic trans-
mission (Refer to 21 - TRANSMISSION/TRANS-
AXLE/AUTOMATIC - 42RE/FLUID - STANDARD
PROCEDURE), (Refer to 21 - TRANSMISSION/
TRANSAXLE/AUTOMATIC - 44RE/FLUID - STAN-
DARD PROCEDURE) or (Refer to 21 -
TRANSMISSION/TRANSAXLE/AUTOMATIC -
46RE/FLUID - STANDARD PROCEDURE).
TRANS COOLER - 8.0L
DESCRIPTION
The air-to-oil cooler is located in front of and to the
left side of the radiator (Fig. 4). This cooler is sup-
plied as standard equipment on all models equipped
with an automatic transmission.
OPERATION
The transmission oil is routed through the cooler
where the cooler removes heat from the transmission
fluid, before returning to the transmission.
Fig. 2 Transmission Oil Cooler - 5.9L Engine
1 - UPPER RADIATOR SUPPORT BRACKET BOLT
2 - MOUNTING STRAPS (2)
3 - TRANS. OIL COOLER UPPER MOUNTING BOLT (2)
4 - TRANS. OIL COOLER LOWER MOUNTING BOLT (2)
5 - LOWER RADIATOR SUPPORT BRACKET BOLT (2)
6 - TRANSMISSION OIL COOLER
7 - RADIATOR SUPPORT BRACKET
Fig. 3 Transmission Oil Cooler Thermostat
Removal/Installation
1 - THERMOSTAT HOUSING
2 - SPRING
3 - END PLUG
4 - SNAP RING
5 - THERMOSTAT
BR/BETRANSMISSION 7 - 81
TRANS COOLER - 5.9L (Continued)

INSTALLATION
(1) Install the oil cooler and cooler line assembly to
the vehicle.
(2) Install three mounting bolts and tighten to 6
N´m (50 in. lbs.) torque.
(3) Connect the transmission cooling lines to the
oil cooler by pushing the rubber hoses onto the oil
cooler tubes. Tighten the worm gear clomps to 2 N´m
(18 in. lbs.)
(4) Start the engine and check all fittings for
leaks.
(5) Check the fluid level in the automatic trans-
mission (Refer to 21 - TRANSMISSION/TRANS-
AXLE/AUTOMATIC - 47RE/FLUID - STANDARD
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-
ers are supplied as standard equipment on diesel
engine powered models when equipped with an auto-
matic transmission.
The main water-to-oil transmission oil cooler is
mounted to a bracket on the turbocharger side of the
engine (Fig. 6).
The air-to-oil cooler is located in front of and to the
left side of the radiator (Fig. 7).
OPERATION
The transmission oil is routed through the main
cooler first, then the auxiliary cooler where addi-
tional heat is removed from the transmission oil
before returning to the transmission.
STANDARD PROCEDURE
STANDARD PROCEDURE - FLUSHING
COOLERS AND TUBES - WITH RADIATOR
IN-TANK TRANSMISSION OIL COOLER
When a transmission failure has contaminated the
fluid, the oil cooler(s) must be flushed. The torque
converter must also be replaced. This will insure that
metal particles or sludged oil are not later trans-
ferred back into the reconditioned (or replaced) trans-
mission.
The only recommended procedure for flushing cool-
ers and lines is to use Tool 6906-B Cooler Flusher.
Fig. 6 Transmission Water-To-Oil CoolerÐDiesel
EngineÐTypical
1 - TRANSMISSION WATER-TO-OIL COOLER
Fig. 7 Auxiliary Transmission Oil CoolerÐDiesel
Engine
1 - CHARGE AIR COOLER (INTERCOOLER)
2 - QUICK-CONNECT FITTINGS (2)
3 - MOUNTING NUTS (2)
4 - MOUNTING BOLT
5 - TRANSMISSION OIL COOLER
7 - 84 TRANSMISSIONBR/BE
TRANS COOLER - 8.0L (Continued)

(1) Disconnect both battery negative cables.
(2) Remove air cleaner assembly and air cleaner
intake hoses.
(3) Drain cooling system (Refer to 7 - COOLING -
STANDARD PROCEDURE).
(4) Disconnect coolant lines from cooler.
(5) Disconnect transmission oil lines from cooler.
Plug cooler lines to prevent oil leakage.
(6) Remove oil cooler mounting straps (Fig. 9).
(7) Lift oil cooler off of mounting bracket.
(8) If replacing cooler, make sure to transfer con-
verter drain back valve to new cooler.INSTALLATION
INSTALLATIONÐAIR TO OIL COOLER
(1) Carefully position the oil cooler assembly to the
vehicle.
(2) Install two nuts and one bolt. Tighten to 11
N´m (95 in. lbs.) torque.
(3) Connect the quick-connect fittings to the trans-
mission cooler lines.
(4) Install front bumper.
(5) Start the engine and check all fittings for
leaks.
(6) Check the fluid level in the automatic trans-
mission (Refer to 21 - TRANSMISSION/TRANS-
AXLE/AUTOMATIC - 47RE/FLUID - STANDARD
PROCEDURE).
INSTALLATION
(1) Position oil cooler on bracket.
(2) Install mounting straps.
(3) Connect transmission oil lines to cooler.
(4) Connect coolant hoses to cooler.
(5) Connect battery negative cables.
(6) Fill cooling system (Refer to 7 - COOLING -
STANDARD PROCEDURE).
(7) Check transmission oil level and fill as neces-
sary (Refer to 21 - TRANSMISSION/TRANSAXLE/
AUTOMATIC - 47RE/FLUID - STANDARD
PROCEDURE).
(8) Install air cleaner assembly and air cleaner
intake hoses.
Fig. 9 Transmission Water-To- Oil CoolerÐDiesel
1 - TRANSMISSION WATER-TO-OIL COOLER
BR/BETRANSMISSION 7 - 87
TRANS COOLER - 5.9L DIESEL (Continued)

assembly. Replace the faulty or damaged antenna
base and cable, if required.
TEST 3
Test 3 checks the condition of the vehicle body
ground connection. This test should be performed
with the battery positive cable removed from the bat-
tery. Disconnect both battery cables, the negative
cable first. Reconnect the battery negative cable and
perform the test as follows:
(1) Connect one ohmmeter test lead to the vehicle
fender. Connect the other test lead to the battery
negative terminal post.
(2) The resistance should be less than one ohm.
(3) If the resistance is more than one ohm, check
the braided ground strap(s) connected to the engine
and the vehicle body for being loose, corroded, or
damaged. Repair the ground strap connections, if
required.
TEST 4
Test 4 checks the condition of the ground between
the antenna base and the vehicle body as follows:
(1) Connect one ohmmeter test lead to the vehicle
fender. Connect the other test lead to the outer crimp
on the antenna coaxial cable connector.
(2) The resistance should be less then one ohm.
(3) If the resistance is more then one ohm, clean
and/or tighten the antenna base to fender mounting
hardware.
REMOVAL
(1) Disconnect and isolate the battery negative
cable.
(2) Reach under the passenger side of the instru-
ment panel near the right cowl side inner panel to
disengage the coaxial cable connector from the
retainer clip located on the bottom of the heater-A/C
housing (Fig. 2).
(3) Remove the foam tape to access the coaxial
cable connector. Disconnect the connector by pulling
it apart while twisting the metal connector halves.
Do not pull on the cable.
(4) Securely tie a suitable length of cord or twine
to the antenna half of the coaxial cable connector.
This cord will be used to pull or ªfishº the cable back
into position during installation.
(5) Reach above the Powertrain Control Module
(PCM) on the right side of the dash panel in the
engine compartment to disengage the antenna coax-
ial cable grommet from the hole in the dash panel
(Fig. 3).
(6) Pull the antenna coaxial cable out of the pas-
senger compartment and into the engine compart-
ment through the hole in the dash panel.(7) Raise the sleeve on the antenna mast far
enough to access and unscrew the antenna mast from
the antenna body (Fig. 4).
(8) Remove the antenna cap nut using an antenna
nut wrench (Special Tool C-4816) (Fig. 5).
(9) Remove the antenna adapter from the top of
the fender.
(10) Lower the antenna body and cable assembly
through the top of the fender.
(11) Pull the antenna body and cable out through
the opening between the right cowl side outer panel
and the top of the fender, while feeding the antenna
coaxial cable out of the engine compartment through
the hole in the right cowl side reinforcement.
(12) Untie the cord or twine from the antenna
body and cable coaxial cable connector, leaving the
cord or twine in the place of the cable through the
vehicle.
(13) Remove the antenna body and cable from the
vehicle.
INSTALLATION
(1) Tie the end of the cord or twine that was used
during instrument panel antenna cable removal
securely to the connector on the end of the antenna
cable being installed into the instrument panel. This
cord will be used to pull or ªfishº the cable back into
position.
Fig. 2 Antenna Coaxial Cable Connector
1 - RETAINER CLIP
2 - TO RADIO
3 - TO ANTENNA
4 - FOAM TAPE
8A - 6 AUDIOBR/BE
ANTENNA BODY & CABLE (Continued)

RADIO NOISE SUPPRESSION
COMPONENTS
DESCRIPTION
Radio Frequency Interference (RFI) and Electro-
Magnetic Interference (EMI) noise suppression is
accomplished primarily through circuitry internal to
the radio receivers. These internal suppression
devices are only serviced as part of the radio receiver.
External suppression devices that are used on this
vehicle to control RFI or EMI noise include the fol-
lowing:
²Radio antenna base ground
²Radio receiver chassis ground wire or strap
²Engine-to-body ground straps
²Cab-to-bed ground strap
²Heater core ground strap
²Resistor-type spark plugs
²Radio suppression-type secondary ignition wir-
ing.
For more information on the spark plugs and sec-
ondary ignition components, refer to Electrical, Igni-
tion Control.
DIAGNOSIS AND TESTING - RADIO NOISE
SUPPRESSION COMPONENTS
WARNING: ON VEHICLES EQUIPPED WITH AIR-
BAGS, REFER TO ELECTRICAL, RESTRAINTS
BEFORE ATTEMPTING ANY STEERING WHEEL,
STEERING COLUMN, OR INSTRUMENT PANEL
COMPONENT DIAGNOSIS OR SERVICE. FAILURE
TO TAKE THE PROPER PRECAUTIONS COULD
RESULT IN ACCIDENTAL AIRBAG DEPLOYMENT
AND POSSIBLE PERSONAL INJURY.
For complete circuit diagrams, refer to the appro-
priate wiring information. The wiring information
includes wiring diagrams, proper wire and connector
repair procedures, details of wire harness routing
and retention, connector pin-out information and
location views for the various wire harness connec-
tors, splices and grounds. Inspect the ground paths
and connections at the following locations:
²Blower motor
²Cab-to-bed ground strap
²Electric fuel pump
²Engine-to-body ground straps
²Generator
²Ignition module
²Heater core ground strap
²Radio antenna base ground
²Radio receiver chassis ground wire or strap
²Wiper motor.If the source of RFI or EMI noise is identified as a
component on the vehicle (i.e., generator, blower
motor, etc.), the ground path for that component
should be checked. If excessive resistance is found in
any ground circuit, clean, tighten, or repair the
ground circuits or connections to ground as required
before considering any component replacement.
For service and inspection of secondary ignition
components, refer to Electrical, Ignition Control.
Inspect the following secondary ignition system com-
ponents:
²Distributor cap and rotor
²Ignition coil
²Spark plugs
²Spark plug wire routing and condition.
Reroute the spark plug wires or replace the faulty
components as required.
If the source of the RFI or EMI noise is identified
as two-way mobile radio or telephone equipment,
check the equipment installation for the following:
²Power connections should be made directly to
the battery, and fused as closely to the battery as
possible.
²The antenna should be mounted on the roof or
toward the rear of the vehicle. Remember that mag-
netic antenna mounts on the roof panel can adversely
affect the operation of an overhead console compass,
if the vehicle is so equipped.
²The antenna cable should be fully shielded coax-
ial cable, should be as short as is practical, and
should be routed away from the factory-installed
vehicle wire harnesses whenever possible.
²The antenna and cable must be carefully
matched to ensure a low Standing Wave Ratio
(SWR).
Fleet vehicles are available with an extra-cost RFI-
suppressed Powertrain Control Module (PCM). This
unit reduces interference generated by the PCM on
some radio frequencies used in two-way radio com-
munications. However, this unit will not resolve com-
plaints of RFI in the commercial AM or FM radio
frequency ranges.
ENGINE-TO-BODY GROUND
STRAP
REMOVAL
(1) Remove the screw that secures the engine-to-
body ground strap eyelet to the dash panel (Fig. 10).
(2) Remove the screw that secures the engine-to-
body ground strap eyelet to the back of the engine
cylinder head (Fig. 11) or (Fig. 12).
8A - 12 AUDIOBR/BE