2002 DODGE RAM air condition

(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 hose clamps and hoses from radiator.
(4) Remove coolant reserve/overflow tank hose
from radiator filler neck nipple.
(5) The coolant recovery/reservoir does not require
removal. Disconnect the overflow hose from the radi-
ator.
(6) Disconnect electrical connectors at windshield
washer reservoir tank and remove tank.
(7) Remove the four fan shroud mounting bolts
(Fig. 37). Position shroud rearward over the fan
blades towards engine.
(8) Remove the two radiator upper mounting bolts
(Fig. 38).
(9) Lift radiator straight up and out of engine com-
partment. The bottom of the radiator is equippedwith two alignment dowels that fit into holes in the
lower radiator support panel (Fig. 38). Rubber bis-
cuits (insulators) are installed to these dowels. Take
care not to damage cooling fins or tubes on the radi-
ator and air conditioning condenser when removing.
CLEANING
Clean radiator fins are necessary for good heat
transfer. The radiator and air conditioning 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
radiator to flush the radiator and/or A/C condenser 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 fan shroud over the fan blades rear-
ward towards engine.
Fig. 37 Fan Shroud MountingÐ8.0L Engine
1 - RADIATOR SUPPORT
2 - RADIATOR
3 - BOLTS (4)
4 - FAN SHROUD
Fig. 38 Typical Radiator Mounting
1 - MOUNTING BOLTS
2 - RADIATOR
3 - ALIGNMENT DOWELS (2)
4 - RADIATOR SUPPORT
BR/BEENGINE 7 - 61
RADIATOR - 8.0L (Continued)

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 hose clamps and hoses from radiator.
(4) Remove coolant reserve/overflow tank hose
from radiator filler neck nipple.
(5) Remove the coolant reserve/overflow tank from
the fan shroud (pull straight up). The tank slips into
T-slots on the fan shroud (Fig. 40). The coolant recov-
ery/reservoir does not require removal. Disconnect
the overflow hose from the radiator.
(6) Disconnect electrical connectors at windshield
washer reservoir tank and remove tank.
(7) Remove the two metal clips retaining the upper
part of fan shroud to the top of radiator.
(8) Remove the four fan shroud mounting bolts
(Fig. 41). Position shroud rearward over the fan
blades towards engine.
(9) Remove the two radiator upper mounting bolts
(Fig. 42).
(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 (Fig. 42). Rubber bis-
cuits (insulators) are installed to these dowels. Take
care not to damage cooling fins or tubes on the radi-
ator and air conditioning condenser when removing.
Fig. 40 Coolant Recovery BottleÐTypical
1 - T-SLOTS
2 - ALIGNMENT PIN
3 - FAN SHROUD
4 - COOLANT RESERVE/OVERFLOW TANK
Fig. 41 Fan Shroud MountingÐ5.9L Diesel Engine
1 - RADIATOR SUPPORT
2 - RADIATOR
3 - BOLTS (4)
4 - FAN SHROUD
Fig. 42 Typical Radiator Mounting
1 - MOUNTING BOLTS
2 - RADIATOR
3 - ALIGNMENT DOWELS (2)
4 - RADIATOR SUPPORT
BR/BEENGINE 7 - 63
RADIATOR - 5.9L DIESEL (Continued)

CLEANING
Clean radiator fins are necessary for good heat
transfer. The radiator and air conditioning 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
radiator to flush the radiator and/or A/C condenser 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 fan shroud over the fan blades rear-
ward towards engine.
(2) Install rubber insulators to alignment dowels
at lower part of radiator.
(3) 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.
(4) Install two upper radiator mounting bolts.
Tighten bolts to 11 N´m (95 in. lbs.) torque.
(5) Connect both radiator hoses and install hose
clamps.
(6) Connect transmission cooler lines to radiator
tank. Inspect quick connect fittings for debris and
install until an audible ªclickº is heard. Pull apart to
verify connection.
(7) Install windshield washer reservoir tank.
(8) Position fan shroud to flanges on sides of radi-
ator. Install fan shroud mounting bolts (Fig. 41).
Tighten bolts to 6 N´m (50 in. lbs.) torque.
(9) Install metal clips to top of fan shroud.
(10) Install coolant reserve/overflow tank hose to
radiator filler neck nipple.
(11) Install coolant reserve/overflow tank to fan
shroud (fits into T-slots on shroud).
(12) Install battery negative cables.
(13) Install positive battery cable to top of radia-
tor. Tighten radiator-to-battery cable mounting nuts.
(14) Position heater controls tofull heatposition.
(15) Fill cooling system with coolant (Refer to 7 -
COOLING - STANDARD PROCEDURE).
(16) Operate engine until it reaches normal tem-
perature. Check cooling system and automatic trans-
mission (if equipped) fluid levels.
RADIATOR PRESSURE CAP
DESCRIPTION
Radiators are equipped with a pressure cap, which
releases pressure at some point within a range of
97-124 kPa (14-18 psi). The pressure relief point (in
pounds) is engraved on top of 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.
A rubber gasket seals radiator filler neck to pre-
vent leakage. This is done to keep system under
pressure. It also maintains vacuum during coolant
cool-down allowing coolant to return from reserve/
overflow tank.
OPERATION
The cap (Fig. 43) contains a spring-loaded pressure
relief valve that opens when system pressure reaches
release range of 97-124 kPa (14-18 psi).
A vent valve in the center of cap allows a small
coolant flow through cap when coolant is below boil-
ing temperature. The valve is completely closed when
boiling point is reached. As the coolant cools, it con-
tracts and creates a vacuum in the cooling system.
This causes the vacuum valve to open and coolant in
the reserve/overflow tank to be drawn through its
connecting hose into radiator. If the vacuum valve is
stuck shut, the radiator hoses will collapse on cool-
down. Clean the vent valve (Fig. 43).
Fig. 43 Radiator Pressure Cap and Filler NeckÐ
Typical
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
7 - 64 ENGINEBR/BE
RADIATOR - 5.9L DIESEL (Continued)

INSPECTION
Hold cap at eye level, right side up. The vent valve
(Fig. 45) at bottom of cap should open. If rubber gas-
ket has swollen and prevents vent valve from open-
ing, replace cap.
Hold cap at eye level, upside down. If any light can
be seen between vent valve and rubber gasket,
replace cap.Do not use a replacement cap that
has a spring to hold vent shut.A replacement cap
must be the type designed for a coolant reserve/over-
flow 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. 46).
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 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
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 DRIVE VISCOUS
CLUTCH - DIAGNOSIS AND TESTING).
(1) Disconnect negative cable from battery.
(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.
Fig. 45 Radiator Pressure Cap
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
Fig. 46 Water Pump LocationÐTypical
1 - WATER PUMP BYPASS HOSE
2 - FAN BLADE ASSEMBLY
3 - VISCOUS FAN DRIVE
4 - WATER PUMP AND PULLEY
7 - 66 ENGINEBR/BE
RADIATOR PRESSURE CAP (Continued)

(2) Using a new gasket, install water pump to
engine as follows: Guide water pump nipple into
bypass hose as pump is being installed. Install water
pump bolts (Fig. 52). Tighten water pump mounting
bolts to 40 N´m (30 ft. lbs.) torque.
(3) Position bypass hose clamp to bypass hose.
(4) Spin water pump to be sure that pump impel-
ler does not rub against timing chain case/cover.
(5) Install a new o-ring to the heater hose coolant
return tube (Fig. 51). Coat the new o-ring with anti-
freeze before installation.
(6) Install coolant return tube and its mounting
bolt to engine (Fig. 51). Be sure the slot in tube
bracket is bottomed to mounting bolt. This will prop-
erly position return tube.
(7) Connect radiator lower hose to water pump.
(8) Connect heater hose and hose clamp to coolant
return tube.
(9) Install drive belt (Refer to 7 - COOLING/AC-
CESSORY DRIVE/DRIVE BELTS - INSTALLATION)
(Fig. 50).
(10) Position fan shroud and fan blade/viscous fan
drive assembly to vehicle as a complete unit.
(11) Install fan shroud.
(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 - 8.0L
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
NOTE:
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 8.0L V-10 engine, a rubber o-ring (instead of
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 couldhave 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 DRIVE VISCOUS
CLUTCH - DIAGNOSIS AND TESTING).
(1) Disconnect negative battery cable from battery.
(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 windshield washer reservoir tank from
radiator fan shroud.
(4) Remove the four fan shroud mounting bolts at
the radiator (Fig. 53). Do not attempt to remove
shroud from vehicle at this time.
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.
(5) Remove radiator upper hose at radiator.
(6) The thermal viscous fan drive is attached
(threaded) to the water pump hub shaft (Fig. 55).
Fig. 53 Typical Fan Shroud Mounting
1 - RADIATOR SUPPORT
2 - RADIATOR
3 - BOLTS (4)
4 - FAN SHROUD
BR/BEENGINE 7 - 69
WATER PUMP - 5.9L (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)

(15) Lift and position generator and A/C compres-
sor (along with their common mounting bracket) to
gain access to bypass hose. A block of wood may be
used to hold assembly in position.
(16) Loosen and position both hose clamps to the
center of bypass hose. A special clamp tool must be
used to remove the constant tension clamps. Remove
hose from vehicle.
REMOVAL - WATER PUMP BYPASS HOSE
WITHOUT AIR CONDITIONING
A water pump bypass hose (Fig. 70) 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 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.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.
(2) Loosen both bypass hose clamps and position to
the center of hose.
(3) Remove hose from vehicle.
INSTALLATION
INSTALLATION - WATER PUMP BYPASS HOSE
WITH AIR CONDITIONING
(1) Position bypass hose clamps to the center of
hose.
(2) Install bypass hose to engine.
(3) Secure both hose clamps.
(4) Install generator-A/C mounting bracket assem-
bly to engine. Tighten bolt number 1 (Fig. 63) to 41
N´m (30 ft. lbs.) torque. Tighten bolt number 2 (Fig.
63) to 28 N´m (20 ft. lbs.) torque. Tighten bracket
mounting bolts (Fig. 68) (Fig. 69) to 40 N´m (30 ft.
lbs.) torque.
(5) Install a new O-ring to the heater hose coolant
return tube (Fig. 66) (Fig. 67). Coat the new O-ring
with antifreeze before installation.
(6) Install coolant return tube and its mounting
bolt to engine (Fig. 66) (Fig. 67).
(7) Connect throttle body control cables.
(8) Install oil dipstick mounting bolt.
(9)/5.9L V-8 LDC-Gas Engine:Install idler pul-
ley. Tighten bolt to 41 N´m (30 ft. lbs.) torque.
Fig. 70 Water Pump Bypass Hose - Typical
1 - WATER PUMP BYPASS HOSE
2 - FAN BLADE ASSEMBLY
3 - VISCOUS FAN DRIVE
4 - WATER PUMP AND PULLEY
7 - 76 ENGINEBR/BE
WATER PUMP INLET TUBE - 5.9L (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)