2002 DODGE RAM Cooling system

GROUP TAB LOCATOR
Introduction
0Lubrication & Maintenance
2Suspension
3Differential & Driveline
5Brakes
6Clutch
7Cooling
8AAudio
8BChime/Buzzer
8EElectronic Control Modules
8FEngine Systems
8GHeated Systems
8HHorn
8IIgnition Control
8JInstrument Cluster
8LLamps
8MMessage Systems
8NPower Systems
8ORestraints
8PSpeed Control
8QVehicle Theft Security
8RWipers/Washers
8WWiring
9Engine
11Exhaust System
13Frame & Bumpers
14Fuel System
19Steering
21Transmission and Transfer Case
22Tires/Wheels
23Body
24Heating & Air Conditioning
25Emissions Control
Component and System Index
Service Manual Comment Forms (Rear of Manual)
NOTE: For New Vehicle Preparation
information, see the separate
publication, 81-170-00003.

²The use of leaded gas is prohibited by Federal
law. Using leaded gasoline can impair engine perfor-
mance, damage the emission control system, and
could result in loss of warranty coverage.
²An out-of-tune engine, or certain fuel or ignition
malfunctions, can cause the catalytic converter to
overheat. If you notice a pungent burning odor or
some light smoke, your engine may be out of tune or
malfunctioning and may require immediate service.
Contact your dealer for service assistance.
²When pulling a heavy load or driving a fully
loaded vehicle when the humidity is low and the tem-
perature is high, use a premium unleaded fuel to
help prevent spark knock. If spark knock persists,
lighten the load, or engine piston damage may result.
²The use of fuel additives which are now being
sold as octane enhancers is not recommended. Most
of these products contain high concentrations of
methanol. Fuel system damage or vehicle perfor-
mance problems resulting from the use of such fuels
or additives is not the responsibility of
DaimlerChrysler Corporation and may not be covered
under the new vehicle warranty.
NOTE: Intentional tampering with emissions control
systems can result in civil penalties being assessed
against you.
DESCRIPTION - FUEL REQUIREMENTS -
DIESEL ENGINE
DESCRIPTION
WARNING: Do not use alcohol or gasoline as a fuel
blending agent. They can be unstable under certain
conditions and hazardous or explosive when mixed
with diesel fuel.
Use good quality diesel fuel from a reputable sup-
plier in your Dodge truck. For most year-round ser-
vice, number 2 diesel fuel meeting ASTM
specification D-975 will provide good performance. If
the vehicle is exposed to extreme cold (below 0ÉF/-
18ÉC), or is required to operate at colder-than-normal
conditions for prolonged periods, use climatized No. 2
diesel fuel or dilute the No. 2 diesel fuel with 50%
No. 1 diesel fuel. This will provide better protection
from fuel gelling or wax-plugging of the fuel filters.
Diesel fuel is seldom completely free of water. To
prevent fuel system trouble, including fuel line freez-
ing in winter, drain the accumulated water from the
fuel/water separator using the fuel/water separator
drain provided. If you buy good-quality fuel and fol-
low the cold-weather advice above, fuel conditioners
should not be required in your vehicle. If available in
your area, a high cetane ªpremiumº diesel fuel mayoffer improved cold starting and warm-up perfor-
mance.
DESCRIPTION - ENGINE COOLANT
WARNING: ANTIFREEZE IS AN ETHYLENE GLYCOL
BASE COOLANT AND IS HARMFUL IF SWAL-
LOWED OR INHALED. IF SWALLOWED, DRINK
TWO GLASSES OF WATER AND INDUCE VOMIT-
ING. IF INHALED, MOVE TO FRESH AIR AREA.
SEEK MEDICAL ATTENTION IMMEDIATELY. DO NOT
STORE IN OPEN OR UNMARKED CONTAINERS.
WASH SKIN AND CLOTHING THOROUGHLY AFTER
COMING IN CONTACT WITH ETHYLENE GLYCOL.
KEEP OUT OF REACH OF CHILDREN. DISPOSE OF
GLYCOL BASE COOLANT PROPERLY, CONTACT
YOUR DEALER OR GOVERNMENT AGENCY FOR
LOCATION OF COLLECTION CENTER IN YOUR
AREA. DO NOT OPEN A COOLING SYSTEM WHEN
THE ENGINE IS AT OPERATING TEMPERATURE OR
HOT UNDER PRESSURE, PERSONAL INJURY CAN
RESULT. AVOID RADIATOR COOLING FAN WHEN
ENGINE COMPARTMENT RELATED SERVICE IS
PERFORMED, PERSONAL INJURY CAN RESULT.
CAUTION: Use of Propylene Glycol based coolants
is not recommended, as they provide less freeze
protection and less corrosion protection.
The cooling system is designed around the coolant.
The coolant must accept heat from engine metal, in
the cylinder head area near the exhaust valves and
engine block. Then coolant carries the heat to the
radiator where the tube/fin radiator can transfer the
heat to the air.
The use of aluminum cylinder blocks, cylinder
heads, and water pumps requires special corrosion
protection. MopartAntifreeze/Coolant, 5
Year/100,000 Mile Formula (MS-9769), or the equiva-
lent ethylene glycol base coolant with organic corro-
sion inhibitors (called HOAT, for Hybrid Organic
Additive Technology) is recommended. This coolant
offers the best engine cooling without corrosion when
mixed with 50% Ethylene Glycol and 50% distilled
water to obtain a freeze point of -37ÉC (-35ÉF). If it
loses color or becomes contaminated, drain, flush,
and replace with fresh properly mixed coolant solu-
tion.
CAUTION: MoparTAntifreeze/Coolant, 5
Year/100,000 Mile Formula (MS-9769) may not be
mixed with any other type of antifreeze. Mixing of
coolants other than specified (non-HOAT or other
HOAT), may result in engine damage that may not
be covered under the new vehicle warranty, and
decreased corrosion protection.
BR/BELUBRICATION & MAINTENANCE 0 - 3
FLUID TYPES (Continued)

COOLANT PERFORMANCE
The required ethylene-glycol (antifreeze) and water
mixture depends upon climate and vehicle operating
conditions. The coolant performance of various mix-
tures follows:
Pure Water-Water can absorb more heat than a
mixture of water and ethylene-glycol. This is for pur-
pose of heat transfer only. Water also freezes at a
higher temperature and allows corrosion.
100 percent Ethylene-Glycol-The corrosion
inhibiting additives in ethylene-glycol need the pres-
ence of water to dissolve. Without water, additives
form deposits in system. These act as insulation
causing temperature to rise to as high as 149ÉC
(300ÉF). This temperature is hot enough to melt plas-
tic and soften solder. The increased temperature can
result in engine detonation. In addition, 100 percent
ethylene-glycol freezes at -22ÉC (-8ÉF).
50/50 Ethylene-Glycol and Water-Is the recom-
mended mixture, it provides protection against freez-
ing to -37ÉC (-34ÉF). The antifreeze concentration
must alwaysbe a minimum of 44 percent, year-
round in all climates. If percentage is lower, engine
parts may be eroded by cavitation. Maximum protec-
tion against freezing is provided with a 68 percent
antifreeze concentration, which prevents freezing
down to -67.7ÉC (-90ÉF). A higher percentage will
freeze at a warmer temperature. Also, a higher per-
centage of antifreeze can cause the engine to over-
heat because specific heat of antifreeze is lower than
that of water.
CAUTION: Richer antifreeze mixtures cannot be
measured with normal field equipment and can
cause problems associated with 100 percent ethyl-
ene-glycol.
COOLANT SELECTION AND ADDITIVES
NOTE: Refer to the vehicle's coolant bottle to iden-
tify HOAT or Non-HOAT coolant. Non-HOAT coolant
is green in color.
The use of aluminum cylinder blocks, cylinder
heads and water pumps requires special corrosion
protection. Only MopartAntifreeze/Coolant, 5
Year/100,000 Mile Formula (glycol base coolant with
corrosion inhibitors called HOAT, for Hybrid Organic
Additive Technology) is recommended. This coolant
offers the best engine cooling without corrosion when
mixed with 50% distilled water to obtain to obtain a
freeze point of -37ÉC (-35ÉF). If it loses color or
becomes contaminated, drain, flush, and replace with
fresh properly mixed coolant solution.CAUTION: Do not use coolant additives that are
claimed to improve engine cooling.
DESCRIPTIONÐENGINE OIL
API SERVICE GRADE CERTIFIED
WARNING: NEW OR USED ENGINE OIL CAN BE
IRRITATING TO THE SKIN. AVOID PROLONGED OR
REPEATED SKIN CONTACT WITH ENGINE OIL.
CONTAMINANTS IN USED ENGINE OIL, CAUSED BY
INTERNAL COMBUSTION, CAN BE HAZARDOUS TO
YOUR HEALTH. THOROUGHLY WASH EXPOSED
SKIN WITH SOAP AND WATER. DO NOT WASH
SKIN WITH GASOLINE, DIESEL FUEL, THINNER, OR
SOLVENTS, HEALTH PROBLEMS CAN RESULT. DO
NOT POLLUTE, DISPOSE OF USED ENGINE OIL
PROPERLY. CONTACT YOUR DEALER OR GOVERN-
MENT AGENCY FOR LOCATION OF COLLECTION
CENTER IN YOUR AREA.
Standard engine-oil identification notations have
been adopted to aid in the proper selection of engine
oil. The identifying notations are located on the label
of engine oil plastic bottles and the top of engine oil
cans.
In diesel engines, use an engine oil that conforms
to API Service Grade CF-4 or CG-4/SH (Fig. 3).
MOPARtprovides an engine oil that conforms to this
particular grade.
SAE VISCOSITY
An SAE viscosity grade is used to specify the vis-
cosity of engine oil. SAE 15W±40 specifies a multiple
viscosity engine oil.
When choosing an engine oil, consider the range of
temperatures the vehicle will be operated in before
the next oil change. Select an engine oil that is best
suited to your area's particular ambient temperature
range and variation. For diesel engines, refer to (Fig.
4).
Fig. 3 API Service Grade Certification LabelÐDiesel
Engine Oil
0 - 4 LUBRICATION & MAINTENANCEBR/BE
FLUID TYPES (Continued)

DESCRIPTION - AUTOMATIC TRANSMISSION
FLUID
NOTE: Refer to the maintenance schedules in this
group for the recommended maintenance (fluid/filter
change) intervals for this transmission.
NOTE: Refer to Service Procedures in this group for
fluid level checking procedures.
MopartATF +4, type 9602, Automatic Transmis-
sion Fluid is the recommended fluid for
DaimlerChrysler automatic transmissions.
Dexron II fluid IS NOT recommended. Clutch
chatter can result from the use of improper
fluid.
MopartATF +4, type 9602, Automatic Transmis-
sion Fluid when new is red in color. The ATF is dyed
red so it can be identified from other fluids used in
the vehicle such as engine oil or antifreeze. The red
color is not permanent and is not an indicator of fluid
condition. As the vehicle is driven, the ATF will begin
to look darker in color and may eventually become
brown.This is normal.A dark brown/black fluid
accompanied with a burnt odor and/or deterioration
in shift quality may indicate fluid deterioration or
transmission component failure.
FLUID ADDITIVES
DaimlerChrysler strongly recommends against the
addition of any fluids to the transmission, other than
those automatic transmission fluids listed above.
Exceptions to this policy are the use of special dyes
to aid in detecting fluid leaks.
Various ªspecialº additives and supplements exist
that claim to improve shift feel and/or quality. These
additives and others also claim to improve converter
clutch operation and inhibit overheating, oxidation,
varnish, and sludge. These claims have not been sup-
ported to the satisfaction of DaimlerChrysler and
these additivesmust not be used.The use of trans-
mission ªsealersº should also be avoided, since they
may adversely affect the integrity of transmission
seals.
OPERATION - AUTOMATIC TRANSMISSION
FLUID
The automatic transmission fluid is selected based
upon several qualities. The fluid must provide a high
level of protection for the internal components by
providing a lubricating film between adjacent metal
components. The fluid must also be thermally stable
so that it can maintain a consistent viscosity through
a large temperature range. If the viscosity stays con-
stant through the temperature range of operation,transmission operation and shift feel will remain con-
sistent. Transmission fluid must also be a good con-
ductor of heat. The fluid must absorb heat from the
internal transmission components and transfer that
heat to the transmission case.
FLUID CAPACITIES
SPECIFICATIONS
FLUID CAPACITIES
DESCRIPTION SPECIFICATION
FUEL TANK
2500 Series Club Cab
and Quad Cab with 6.5'
Short Box129 L (34 gal.)*****
All 8' Long Box 132 L (35 gal.)*****
All Cab/Chassis Models 132 L (35 gal.)*****
ENGINE OIL WITH FILTER
5.9L 4.7 L (5.0 qts.)
8.0L 6.6 L (7.0 qts.)
5.9L DIESEL 10.4 L (11.0 qts.)
COOLING SYSTEM
5.9L 19 L (20 qts.)****
8.0L 24.5 L (26.0 qts.)****
5.9L DIESEL 22.7 L (24.0 qts.)****
POWER STEERING
Power steering fluid capacities are dependent on
engine/chassis options as well as steering gear/cooler
options. Depending on type and size of internal
cooler, length and inside diameter of cooler lines, or
use of an auxiliary cooler, these capacities may vary.
Refer to 19, Steering for proper fill and bleed
procedures.
AUTOMATIC TRANSMISSION
Service Fill - 46RE 3.8 L (4.0 qts.)
O-haul - 46RE 9-9.5L (19-20 pts.)*
Service Fill - 47RE 3.8 L (4.0 qts.)
O-haul - 47RE 14-16 L (29-33 pts.)*
0 - 6 LUBRICATION & MAINTENANCEBR/BE
FLUID TYPES (Continued)

COOLING
TABLE OF CONTENTS
page page
COOLING
DESCRIPTION
DESCRIPTION - COOLING SYSTEM FLOW -
5.9L ENGINE..........................1
DESCRIPTIONÐCOOLING SYSTEM FLOW -
5.9L DIESEL..........................2
DESCRIPTIONÐHOSE CLAMPS...........4
OPERATION
OPERATIONÐHOSE CLAMPS............4
OPERATIONÐCOOLING SYSTEM.........4
DIAGNOSIS AND TESTING
DIAGNOSIS AND TESTING - PRELIMINARY
CHECKS.............................4
DIAGNOSIS AND TESTINGÐON-BOARD
DIAGNOSTICS (OBD)...................5
DIAGNOSIS AND TESTING - COOLING
SYSTEM LEAKS.......................5
DIAGNOSIS AND TESTING - COOLING
SYSTEM GAS ENGINE..................7
DIAGNOSIS AND TESTING - COOLING
SYSTEM DIESEL ENGINE...............13
STANDARD PROCEDURE
STANDARD PROCEDURE - DRAINING
COOLING SYSTEM 5.9L/8.0L ENGINES....15STANDARD PROCEDUREÐDRAINING
COOLING SYSTEM 5.9L DIESEL ENGINE . . . 15
STANDARD PROCEDURE - REFILLING
COOLING SYSTEM 5.9L/8.0L ENGINES....16
STANDARD PROCEDUREÐREFILLING
COOLING SYSTEM 5.9L DIESEL ENGINE . . . 16
STANDARD PROCEDURE - ADDING
ADDITIONAL COOLANT.................16
STANDARD PROCEDUREÐCOOLANT
LEVEL CHECK........................16
STANDARD PROCEDURE - COOLING
SYSTEM CLEANING/REVERSE FLUSHING . . 17
STANDARD PROCEDURE - COOLANT
SELECTION - ADDITIVES...............17
SPECIFICATIONS
TORQUE............................18
SPECIAL TOOLS
COOLING...........................18
ACCESSORY DRIVE......................19
ENGINE...............................38
TRANSMISSION.........................78
COOLING
DESCRIPTION
DESCRIPTION - COOLING SYSTEM FLOW -
5.9L ENGINE
The cooling system regulates engine operating tem-
perature. It allows the engine to reach normal oper-
ating temperature as quickly as possible. It also
maintains normal operating temperature and pre-
vents overheating.The cooling system also provides a means of heat-
ing the passenger compartment and cooling the auto-
matic transmission fluid (if equipped). The cooling
system is pressurized and uses a centrifugal water
pump to circulate coolant throughout the system.
An optional factory installed maximum duty cool-
ing package is available on most models. This pack-
age will provide additional cooling capacity for
vehicles used under extreme conditions such as
trailer towing in high ambient temperatures (Fig. 1).
BR/BECOOLING 7 - 1

DESCRIPTIONÐCOOLING SYSTEM FLOW -
5.9L DIESEL
The diesel engine cooling system consists of (Fig.
2):
²Cross-flow radiator
²Belt driven water pump
²Belt driven mechanical cooling fan
²Thermal viscous fan drive
²Fan shroud
²Radiator pressure cap
²Vertically mounted thermostat
²Coolant reserve/recovery system
²Transmission oil cooler
²Coolant
Coolant flow circuits for the 5.9L diesel engine are
shown in (Fig. 3).
Fig. 1 Engine Cooling System Flow
1 - HEATER
2 - BYPASS*3 - CROSSFLOW RADIATOR
Fig. 2 Cooling System Components 5.9L Diesel
Engine
1 - RADIATOR CAP
2 - AUXILIARY TRANSMISSION OIL COOLER
3 - CHARGE AIR COOLER
4 - RADIATOR LOWER HOSE
5 - OVERFLOW/RESERVOIR BOTTLE
6 - FAN SHROUD
7 - RADIATOR UPPER HOSE
8 - CONSTANT TENSION CLAMP
7 - 2 COOLINGBR/BE
COOLING (Continued)

Fig. 3 Cooling System CirculationÐDiesel Engine
BR/BECOOLING 7 - 3
COOLING (Continued)

DESCRIPTIONÐHOSE CLAMPS
The cooling system utilizes both worm drive and
spring type hose clamps. If a spring type clamp
replacement is necessary, replace with the original
Mopartequipment spring type clamp.
CAUTION: A number or letter is stamped into the
tongue of constant tension clamps. If replacement
is necessary, use only a original equipment clamp
with matching number or letter (Fig. 4).
OPERATION
OPERATIONÐHOSE CLAMPS
The worm type hose clamp uses a specified torque
value to maintain proper tension on a hose connec-
tion.
The spring type hose clamp applies constant ten-
sion on a hose connection. To remove a spring type
hose clamp, only use constant tension clamp pliers
designed to compress the hose clamp.
OPERATIONÐCOOLING SYSTEM
The cooling system regulates engine operating tem-
perature. It allows the engine to reach normal oper-
ating temperature as quickly as possible. It also
maintains normal operating temperature and pre-
vents overheating.
The cooling system also provides a means of heat-
ing the passenger compartment and cooling the auto-
matic transmission fluid (if equipped). The cooling
system is pressurized and uses a centrifugal water
pump to circulate coolant throughout the system.
An optional factory installed maximum duty cool-
ing package is available on most models. This pack-age will provide additional cooling capacity for
vehicles used under extreme conditions such as
trailer towing in high ambient temperatures.
DIAGNOSIS AND TESTING
DIAGNOSIS AND TESTING - PRELIMINARY
CHECKS
ENGINE COOLING SYSTEM OVERHEATING
Establish what driving conditions caused the com-
plaint. Abnormal loads on the cooling system such as
the following may be the cause:
²PROLONGED IDLE
²VERY HIGH AMBIENT TEMPERATURE
²SLIGHT TAIL WIND AT IDLE
²SLOW TRAFFIC
²TRAFFIC JAMS
²HIGH SPEED OR STEEP GRADES
Driving techniques that avoid overheating are:
²Idle with A/C off when temperature gauge is at
end of normal range.
²Increasing engine speed for more air flow is rec-
ommended.
TRAILER TOWING:
Consult Trailer Towing section of owners manual.
Do not exceed limits.
AIR CONDITIONING; ADD-ON OR AFTER MARKET:
A maximum cooling package should have been
ordered with vehicle if add-on or after market A/C is
installed. If not, maximum cooling system compo-
nents should be installed for model involved per
manufacturer's specifications.
RECENT SERVICE OR ACCIDENT REPAIR:
Determine if any recent service has been per-
formed on vehicle that may effect cooling system.
This may be:
²Engine adjustments (incorrect timing)
²Slipping engine accessory drive belt(s)
²Brakes (possibly dragging)
²Changed parts. Incorrect water pump or pump
rotating in wrong direction due to belt not correctly
routed
²Reconditioned radiator or cooling system refill-
ing (possibly under filled or air trapped in system).
NOTE: If investigation reveals none of the previous
items as a cause for an engine overheating com-
plaint, (Refer to 7 - COOLING - DIAGNOSIS AND
TESTING)
Fig. 4 Spring Clamp Size Location
1 - SPRING CLAMP SIZE LOCATION
7 - 4 COOLINGBR/BE
COOLING (Continued)