
CONDITION POSSIBLE CAUSES CORRECTION
NOISE (Objectional squeal, spueak,
or rumble is heard or felt while drive
belt is in operation)1. Incorrect belt tension 1. Inspect/Replace tensioner if
necessary
2. Bearing noise 2. Locate and repair
3. Belt misalignment 3. Align belt/pulley(s)
4. Belt to pulley mismatch 4. Install correct belt
5. Driven component induced
vibration5. Locate defective driven
component and repair
TENSION SHEETING FABRIC
FAILURE
(Woven fabric on outside,
circumference of belt has cracked or
separated from body of belt)1. Tension sheeting contacting
stationary object1. Correct rubbing condition
2. Excessive heat causing woven
fabric to age2. Replace belt
3. Tension sheeting splice has
fractured3. Replace belt
CORD EDGE FAILURE
(Tensile member exposed at edges
of belt or separated from belt body)1. Incorrect belt tension 1. Inspect/Replace tensioner if
necessary
2. Belt contacting stationary object 2. Replace belt
3. Pulley(s) out of tolerance 3. Replace pulley
4. Insufficient adhesion between
tensile member and rubber matrix4. Replace belt
REMOVAL
CAUTION: Do not attempt to check belt tension with
a belt tension gauge on vehicles equipped with an
automatic belt tensioner. Refer to Automatic Belt
Tensioner in this group.
NOTE: The belt routing schematics are published
from the latest information available at the time of
publication. If anything differs between these sche-
matics and the Belt Routing Label, use the sche-
matics on Belt Routing Label.This label is located in
the engine compartment.
Drive belts on diesel engines are equipped with a
spring loaded automatic belt tensioner (Fig. 20).
(Fig. 20)displays the tensioner for vehicles
without air conditioning.
This belt tensioner will be used on all belt config-
urations, such as with or without air conditioning.
For more information, (Refer to 7 - COOLING/AC-
CESSORY DRIVE/BELT TENSIONERS - DESCRIP-
TION).
(1) A 3/8 inch square hole is provided in the auto-
matic belt tensioner (Fig. 20). Attach a 3/8 inch
drive-long handle ratchet to this hole.
(2) Rotate ratchet and tensioner assembly counter-
clockwise (as viewed from front) until tension has
been relieved from belt.(3) Remove belt from water pump pulley first.
(4) Remove belt from vehicle.
Fig. 20 Belt TensionerÐ5.9L DieselÐTypical
(non-A/C shown)
1 - WATER PUMP
2 - ACCESSORY DRIVE BELT
3 - AUTOMATIC BELT TENSIONER
4 - 3/89SQUARE BOLT
5 - MOUNT. BOLT
BR/BEACCESSORY DRIVE 7 - 33
DRIVE BELTS - 5.9L DIESEL (Continued)

DIAGNOSIS AND TESTING.................63
RADIATOR COOLANT FLOW..............63
REMOVAL..............................63
CLEANING..............................65
INSPECTION............................65
INSTALLATION...........................65
RADIATOR PRESSURE CAP
DESCRIPTION...........................65
OPERATION.............................65
DIAGNOSIS AND TESTING.................66
RADIATOR CAP-TO-FILLER NECK SEAL.....66
RADIATOR CAP........................66
CLEANING..............................66
INSPECTION............................66
WATER PUMP - 3.9L/5.2L/5.9L
DESCRIPTION...........................67
OPERATION.............................67
DIAGNOSIS AND TESTING.................67
WATER PUMP.........................67
REMOVAL..............................67
CLEANING..............................69INSPECTION............................69
INSTALLATION...........................70
WATER PUMP - 8.0L
DIAGNOSIS AND TESTING.................70
WATER PUMP.........................70
REMOVAL..............................70
CLEANING..............................72
INSPECTION............................72
INSTALLATION...........................72
WATER PUMP - 5.9L DIESEL
DESCRIPTION...........................73
OPERATION.............................73
DIAGNOSIS AND TESTING.................73
WATER PUMP.........................73
REMOVAL..............................73
CLEANING..............................73
INSPECTION............................73
INSTALLATION...........................74
WATER PUMP INLET TUBE - 3.9L/5.2L/5.9L
REMOVAL..............................74
INSTALLATION...........................77
COOLANT
DESCRIPTION
ETHYLENE-GLYCOL MIXTURES
CAUTION: Richer antifreeze mixtures cannot be
measured with normal field equipment and can
cause problems associated with 100 percent ethyl-
ene-glycol.
The required ethylene-glycol (antifreeze) and water
mixture depends upon the climate and vehicle oper-
ating conditions. The recommended mixture of 50/50
ethylene-glycol and water will provide protection
against freezing to -37 deg. C (-35 deg. F). The anti-
freeze concentrationmust alwaysbe a minimum of
44 percent, year-round in all climates.If percentage
is lower than 44 percent, engine parts may be
eroded by cavitation, and cooling system com-
ponents may be severely damaged by corrosion.
Maximum protection against freezing is provided
with a 68 percent antifreeze concentration, which
prevents freezing down to -67.7 deg. C (-90 deg. F). A
higher percentage will freeze at a warmer tempera-
ture. Also, a higher percentage of antifreeze can
cause the engine to overheat because the specific
heat of antifreeze is lower than that of water.
Use of 100 percent ethylene-glycol will cause for-
mation of additive deposits in the system, as the cor-
rosion inhibitive additives in ethylene-glycol require
the presence of water to dissolve. The deposits act as
insulation, causing temperatures to rise to as high as
149 deg. C (300) deg. F). This temperature is hot
enough to melt plastic and soften solder. Theincreased temperature can result in engine detona-
tion. In addition, 100 percent ethylene-glycol freezes
at 22 deg. C (-8 deg. F ).
PROPYLENE-GLYCOL MIXTURES
It's overall effective temperature range is smaller
than that of ethylene-glycol. The freeze point of 50/50
propylene-glycol and water is -32 deg. C (-26 deg. F).
5 deg. C higher than ethylene-glycol's freeze point.
The boiling point (protection against summer boil-
over) of propylene-glycol is 125 deg. C (257 deg. F )
at 96.5 kPa (14 psi), compared to 128 deg. C (263
deg. F) for ethylene-glycol. Use of propylene-glycol
can result in boil-over or freeze-up on a cooling sys-
tem designed for ethylene-glycol. Propylene glycol
also has poorer heat transfer characteristics than
ethylene glycol. This can increase cylinder head tem-
peratures under certain conditions.
Propylene-glycol/ethylene-glycol Mixtures can cause
the destabilization of various corrosion inhibitors,
causing damage to the various cooling system compo-
nents. Also, once ethylene-glycol and propylene-glycol
based coolants are mixed in the vehicle, conventional
methods of determining freeze point will not be accu-
rate. Both the refractive index and specific gravity dif-
fer between ethylene glycol and propylene glycol.
OPERATION
Coolant flows through the engine block absorbing the
heat from the engine, then flows to the radiator where
the cooling fins in the radiator transfers the heat from
the coolant to the atmosphere. During cold weather the
ethylene-glycol coolant prevents water present in the
cooling system from freezing within temperatures indi-
cated by mixture ratio of coolant to water.
7 - 40 ENGINEBR/BE

COOLANT RECOVERY
CONTAINER - 3.9L/5.2L/5.9L/
5.9L DIESEL
DESCRIPTION
The coolant reserve/overflow tank is mounted to
the side of the fan shroud (Fig. 1), and is made of
high temperature plastic.
OPERATION
The coolant reserve/overflow system works in con-
junction with the radiator pressure cap. It utilizes
thermal expansion and contraction of coolant to keep
coolant free of trapped air. It provides a volume for
expansion and contraction of coolant. It also provides
a convenient and safe method for checking coolant
level and adjusting level at atmospheric pressure.
This is done without removing the radiator pressurecap. The system also provides some reserve coolant
to the radiator to cover minor leaks and evaporation
or boiling losses.
As the engine cools, a vacuum is formed in the
cooling system of both the radiator and engine. Cool-
ant will then be drawn from the coolant tank and
returned to a proper level in the radiator.
REMOVAL
(1) Remove overflow hose from radiator.
(2) Unsnap the coolant reserve/overflow tank from
fan shroud. Lift straight up. The fan shroud is
equipped with T-shaped slots (Fig. 2) to attach the
tank. An alignment pin is located on the side of tank.
INSTALLATION
(1) Snap the tank into the two T-slots and the
alignment pin on fan shroud (Fig. 3).
(2) Connect overflow hose to radiator.
Fig. 1 Coolant Reserve/Overflow Tank
1 - T-SLOTS
2 - ALIGNMENT PIN
3 - FAN SHROUD
4 - COOLANT RESERVE/OVERFLOW TANK
Fig. 2 COOLANT RESERVE/OVERFLOW TANKÐALL
EXCEPT 8.0L V-10 ENGINE
1 - T-SLOTS
2 - ALIGNMENT PIN
3 - FAN SHROUD
4 - COOLANT RESERVE/OVERFLOW TANK
BR/BEENGINE 7 - 41

COOLANT RECOVERY
CONTAINER - 8.0L
DESCRIPTION
On the 8.0L V-10 engine the tank is mounted to
right inner fender (Fig. 4), and is made of high tem-
perature plastic.
OPERATION
The coolant reserve/overflow system works in con-
junction with the radiator pressure cap. It utilizes
thermal expansion and contraction of coolant to keep
coolant free of trapped air. It provides a volume for
expansion and contraction of coolant. It also provides
a convenient and safe method for checking coolant
level and adjusting level at atmospheric pressure.
This is done without removing the radiator pressure
cap. The system also provides some reserve coolant
to the radiator to cover minor leaks and evaporation
or boiling losses.
As the engine cools, a vacuum is formed in the
cooling system of both the radiator and engine. Cool-
ant will then be drawn from the coolant tank and
returned to a proper level in the radiator.
RADIATOR FAN - 3.9L/5.2L/
5.9L/8.0L
REMOVAL
CAUTION: If the viscous fan drive is replaced
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.
(1) Disconnect negative battery cable from battery.
(2) Remove throttle cable at top of fan shroud.
(3) All Except 8.0L V-10 Engine: Unsnap coolant
reserve/overflow tank from fan shroud and lay aside.
The tank is held to shroud with T- shaped slots. Do
not disconnect hose or drain coolant from tank.
(4) The thermal viscous fan drive/fan blade assem-
bly is attached (threaded) to water pump hub shaft
(Fig. 6). Remove fan blade/viscous fan drive assembly
from water pump by turning mounting nut counter-
clockwise as viewed from front. Threads on viscous
fan drive areRIGHT-HAND.A Snap-On 36 MM Fan
Wrench (number SP346 from Snap-On Cummins Die-
sel Tool Set number 2017DSP), Special Tool 6958
Spanner Wrench and Adapter Pins 8346 should be
used to prevent pulley from rotating (Fig. 5).
(5) Do not attempt to remove fan/viscous fan drive
assembly from vehicle at this time.
Fig. 3 COOLANT RESERVE/OVERFLOW TANKÐALL
EXCEPT 8.0L V-10 ENGINE
1 - T-SLOTS
2 - ALIGNMENT PIN
3 - FAN SHROUD
4 - COOLANT RESERVE/OVERFLOW TANK
Fig. 4 Coolant Reserve/Overflow TankÐ8.0L V-10
Engine
1 - COOLANT RESERVE/OVERFLOW TANK
2 - TANK MOUNTING BOLTS (3)
3 - ICM MOUNTING BOLTS (2)
4 - IGNITION CONTROL MODULE (ICM)
7 - 42 ENGINEBR/BE
COOLANT RECOVERY CONTAINER - 3.9L/5.2L/5.9L/5.9L DIESEL (Continued)

(4) Install fan blade/viscous fan drive assembly to
water pump shaft (Fig. 6).
(5) Except 8.0L V-10 Engine: Install coolant
reserve/overflow tank to fan shroud. Snaps into posi-
tion.
(6) Install throttle cable to fan shroud.
(7) Connect negative battery cable.
NOTE: Viscous Fan Drive Fluid Pump Out Require-
ment: After installing a new viscous fan drive, bring
the engine speed up to approximately 2000 rpm and
hold for approximately two minutes. This will
ensure proper fluid distribution within the drive.
RADIATOR FAN - 5.9L DIESEL
REMOVAL
CAUTION: If the viscous fan drive is replaced
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.
(1) Disconnect the battery negative cables.
(2) Remove the fan shroud mounting bolts. Posi-
tion fan shroud towards engine.
CAUTION: Do not remove the fan pulley bolts. This
pulley is under spring tension.
(3) The thermal viscous fan drive/fan blade assem-
bly is attached (threaded) to the fan hub shaft (Fig.
7). Remove the fan blade/fan drive assembly from fan
pulley by turning the mounting nut clockwise (as
viewed from front). Threads on the viscous fan drive
areLEFT-HAND.A Snap-On 36 MM Fan Wrench
(number SP346 from Snap-On Cummins Diesel Tool
Set number 2017DSP) can be used. Place a bar or
screwdriver between the fan pulley bolts to prevent
pulley from rotating.
(4) Remove the fan shroud and the fan blade/vis-
cous drive as an assembly from vehicle.
(5) Remove fan blade-to-viscous fan drive mount-
ing bolts.
(6) Inspect the fan for cracks, loose rivets, loose or
bent fan blades.
CAUTION: Some engines equipped with serpentine
drive belts have reverse rotating fans and viscous
fan drives. They are marked with the wordREVERSE to designate their usage. Installation of
the wrong fan or viscous fan drive can result in
engine overheating.
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.
Fig. 7 Fan Blade/Viscous Fan Drive
1 - THREADED SHAFT
2 - BOLT (4)
3 - FAN BLADE
4 - THREADED NUT
5 - VISCOUS FAN DRIVE
7 - 44 ENGINEBR/BE
RADIATOR FAN - 3.9L/5.2L/5.9L/8.0L (Continued)

(3) Inspect fan assembly for cracks, bends, loose
rivets or broken welds. Replace fan if any damage is
found.
INSTALLATION
(1) Install fan blade assembly to viscous fan drive.
Tighten mounting bolts to 23 N´m (17 ft. lbs.) torque.
(2) Position the fan shroud and fan blade/viscous
fan drive to the vehicle as an assembly.
(3) Install viscous fan drive assembly on fan hub
shaft (Fig. 7). Tighten mounting nut to 57 N´m (42 ft.
lbs.) torque.
(4) Install fan shroud bolts into position and
tighten the mounting bolts to 6 N´m (50 in. lbs.)
torque.
(5) Connect the battery negative cables.
NOTE: Viscous Fan Drive Fluid Pump Out Require-
ment: After installing a new viscous fan drive, bring
the engine speed up to approximately 2000 rpm and
hold for approximately two minutes. This will
ensure proper fluid distribution within the drive.
ENGINE BLOCK HEATER -
3.9L/5.2L/5.9L
DESCRIPTION
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 is available on all
models. The heater is equipped with a power cord.
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. The
cord is attached to an engine compartment compo-
nent with tie-straps.
The 3.9L and 5.9L gas powered engine has the
block heater located on the right side of engine next
to the oil filter (Fig. 8).
OPERATION
The heater warms the engine coolant providing
easier engine starting and faster warm-up in low
temperatures. Connecting the power cord to a
grounded 110-120 volt AC electrical outlet with a
grounded three wire extension cord provides the elec-
tricity needed to heat the element..
REMOVAL
(1) Disconnect battery negative cable.
(2) Drain coolant (Refer to 7 - COOLING - STAN-
DARD PROCEDURE).
(3) Remove power cord from heater by unplugging
(Fig. 9).
(4) Loosen (but do not completely remove) the
screw at center of block heater (Fig. 9).
(5) Remove block heater by carefully prying from
side-to-side. Note direction of heating element coil
(up or down). Element coil must be installed correctly
to prevent damage.
INSTALLATION
(1) Clean and inspect the block heater hole.
(2) Install new O-ring seal(s) to heater in gasoline
engines.
(3) Insert block heater into cylinder block.
(4) With heater fully seated, tighten center screw
to 2 N´m (17 in. lbs.).
(5) Fill cooling system with recommended coolant.
(Refer to 7 - COOLING - STANDARD PROCE-
DURE).
(6) Start and warm the engine.
(7) Check block heater for leaks.
Fig. 8 Engine Block Heater
1 - FREEZE PLUG HOLE
2 - BLOCK HEATER
3 - SCREW
4 - POWER CORD (120V AC)
5 - HEATING COIL
6 - OIL FILTER
BR/BEENGINE 7 - 45
RADIATOR FAN - 5.9L DIESEL (Continued)

ENGINE BLOCK HEATER - 8.0L
DESCRIPTION
An optional engine block heater is available on all
models. The heater is equipped with a power cord.
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. The
cord is attached to an engine compartment compo-
nent with tie-straps.
The 8.0L V-10 engine has the block heater located
on the right side of engine next to the engine oil dip-
stick tube (Fig. 10).
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.
OPERATION
The heater warms the engine coolant providing
easier engine starting and faster warm-up in low
temperatures. Connecting the power cord to agrounded 110-120 volt AC electrical outlet with a
grounded three wire extension cord provides the elec-
tricity needed to heat the element..
REMOVAL
(1) Disconnect battery negative cable.
(2) Drain coolant from radiator and cylinder block
(Refer to 7 - COOLING - STANDARD PROCE-
DURE).
(3) Remove power cord from heater by unplugging
(Fig. 11).
(4) Loosen (but do not completely remove) the
screw at center of block heater (Fig. 11).
(5) Remove block heater by carefully prying from
side-to-side. Note direction of heating element coil
(up or down). Element coil must be installed correctly
to prevent damage.
INSTALLATION
(1) Clean and inspect the block heater hole.
(2) Install new O-ring seal(s) to heater in gasoline
engines.
(3) Insert block heater into cylinder block.
(4) With heater fully seated, tighten center screw
to 2 N´m (17 in. lbs.).
Fig. 9 Engine Block Heater
1 - FREEZE PLUG HOLE
2 - BLOCK HEATER
3 - SCREW
4 - POWER CORD (120V AC)
5 - HEATING COIL
6 - OIL FILTER
Fig. 10 Engine Block HeaterÐ8.0L V-10 Engine
1 - FREEZE PLUG HOLE
2 - SCREW
3 - POWER CORD (120V AC)
4 - BLOCK HEATER
5 - HEATING COIL
7 - 46 ENGINEBR/BE
ENGINE BLOCK HEATER - 3.9L/5.2L/5.9L (Continued)

(5) Fill cooling system with recommended coolant
(Refer to 7 - COOLING - STANDARD PROCE-
DURE).
(6) Start and warm the engine.
(7) Check block heater for leaks.
ENGINE BLOCK HEATER - 5.9L
DIESEL
DESCRIPTION
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 is available on all
models. The heater is equipped with a power cord.
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. The
cord is attached to an engine compartment compo-
nent with tie-straps.The 5.9L diesel engine has the block heater located
on the right side of the engine below the exhaust
manifold next to the oil cooler (Fig. 12).
OPERATION
The heater warms the engine coolant providing
easier engine starting and faster warm-up in low
temperatures. Connecting the power cord to a
grounded 110-120 volt AC electrical outlet with a
grounded three wire extension cord provides the elec-
tricity needed to heat the element..
REMOVAL
(1) Disconnect the battery negative cables.
(2) Drain coolant from radiator and cylinder block
(Refer to 7 - COOLING - STANDARD PROCE-
DURE).
(3) Unscrew the power cord retaining cap and dis-
connect cord from heater element.
(4) Using a suitable size socket, loosen and remove
the block heater element (Fig. 13).
INSTALLATION
(1) Clean and inspect the threads in the cylinder
block.
(2) Coat heater element threads with Mopart
Thread Sealer with Teflon.
(3) Screw block heater into cylinder block and
tighten to 43 N´m (32 ft. lbs.).
(4) Connect block heater cord and tighten retain-
ing cap.
(5) Fill cooling system with recommended coolant
(Refer to 7 - COOLING - STANDARD PROCE-
DURE).
(6) Start and warm the engine.
(7) Check block heater for leaks.
Fig. 11 Block HeaterÐ8.0L V-10 Engine
1 - FREEZE PLUG HOLE
2 - SCREW
3 - POWER CORD (120V AC)
4 - BLOCK HEATER
5 - HEATING COIL
Fig. 12 Engine Block HeaterÐ5.9L Diesel Engine
1 - BLOCK HEATER
BR/BEENGINE 7 - 47
ENGINE BLOCK HEATER - 8.0L (Continued)