Dodge Dakota (R1). Manual - part 261

(9) After removing fan blade/viscous fan drive

assembly, do not place thermal viscous fan drive in
horizontal position. If stored horizontally, silicone
fluid in viscous fan drive could drain into its bearing
assembly and contaminate lubricant.

(10) Remove the accessory drive belt (Refer to 7 -

COOLING/ACCESSORY

DRIVE/DRIVE

BELTS

REMOVAL).

(11) Remove lower radiator hose clamp and remove

lower hose at water pump.

(12) Remove heater hose clamp and heater hose

from heater hose coolant return tube.

(13) Loosen

heater

hose

coolant

return

tube

mounting bolt (Fig. 48) and remove tube from water
pump. Discard the old tube O-ring.

(14) Remove seven water pump mounting bolts.
(15) Loosen clamp at water pump end of bypass

hose (Fig. 47). Slip bypass hose from water pump
while removing pump from vehicle. Discard old gas-
ket.

CAUTION: Do not pry water pump at timing chain
case/cover. The machined surfaces may be dam-
aged resulting in leaks.

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, Loose or rough
turning bearing or Impeller rubbing either the pump
body or timing chain case/cover.

INSTALLATION

(1) Clean gasket mating surfaces.
(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. 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. 48). Coat the new O-ring with anti-
freeze before installation.

(6) Install coolant return tube and its mounting

bolt to engine (Fig. 48). 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 accessory drive belt (Refer to 7 - COOL-

ING/ACCESSORY DRIVE/DRIVE BELTS - INSTAL-
LATION).

(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.

Fig. 47 Fan Blade and Viscous Fan Drive

1 - WATER PUMP BYPASS HOSE
2 - FAN BLADE ASSEMBLY
3 - VISCOUS FAN DRIVE
4 - WATER PUMP AND PULLEY

Fig. 48 Coolant Return Tube—Typical

1 - COOLANT RETURN TUBE
2 - WATER PUMP
3 - TUBE MOUNTING BOLT
4 - O-RING

7 - 56

ENGINE

WATER PUMP - 3.9L/5.9L (Continued)

(13) Fill cooling system. (Refer to 7 - COOLING -

STANDARD PROCEDURE).

(14) Connect battery negative cable.
(15) Start and warm the engine. Check for leaks.

WATER PUMP - 4.7L

DESCRIPTION—WATER PUMP

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.
49).

DESCRIPTION—WATER PUMP BYPASS

The 4.7L engine uses an internal water/coolant

bypass system. The design uses galleries in the tim-
ing 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. 50)
to control flow through the bypass gallery.

OPERATION

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.

Fig. 49 Water Pump and Timing Chain Cover

1 - INTEGRAL WATER PUMP PULLEY
2 - TIMING CHAIN COVER
3 - THERMOSTAT HOUSING
4 - HEATER HOSE FITTINGS
5 - WATER PUMP

Fig. 50 Water/Coolant Bypass Flow and Thermostat

1 - FROM HEATER
2 - FROM RADIATOR
3 - TO WATER PUMP
4 - ENGINE BYPASS
5 - THERMOSTAT

ENGINE

7 - 57

WATER PUMP - 3.9L/5.9L (Continued)

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 4.7L engines is bolted directly

to the engine timing chain case cover.

(1) Disconnect negative battery cable from battery.
(2) Drain cooling system (Refer to 7 - COOLING -

STANDARD PROCEDURE).

(3) Remove fan/viscous fan drive assembly from

water pump (Fig. 51) (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.
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 matching number or letter.

(4) If water pump is being replaced, do not unbolt

fan blade assembly from thermal viscous fan drive.

(5) Remove two fan shroud-to-radiator screws (Fig.

52). Disconnect the coolant overflow hose, windshield
washer fluid hose and washer pump electrical con-
nector.

Fig. 51 Viscous Fan and Fan Drive 4.7L

1 - SPECIAL TOOL 6958 SPANNER WRENCH WITH ADAPTER
PINS 8346
2 - FAN

Fig. 52 Upper Fan Shroud, Coolant reservoir and

Washer Fluid Reservoir

1 - RADIATOR
2 - WASHER FLUID RESERVOIR
3 - COOLANT OVERFLOW/RESERVOIR
4 - FAN SHROUD (UPPER)
5 - SCREW
6 - INTERLOCKING PINS
7 - FAN SHROUD (LOWER)

7 - 58

ENGINE

WATER PUMP - 4.7L (Continued)

(6) Remove upper fan shroud and fan blade/viscous

fan drive assembly from vehicle.

(7) After removing fan blade/viscous fan drive

(8) Remove accessory drive belt (Fig. 53) (Refer to

7 - COOLING/ACCESSORY DRIVE/DRIVE BELTS -
REMOVAL).

(9) Remove lower radiator hose clamp and remove

lower hose at water pump.

(10) Remove seven water pump mounting bolts

and one stud bolt.

CAUTION: Do not pry water pump at timing chain
case/cover. The machined surfaces may be dam-
aged resulting in leaks.

(11) Remove water pump and gasket. Discard gas-

ket.

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, Loose or rough
turning bearing or Impeller rubbing either the pump
body or timing chain case/cover.

INSTALLATION

The water pump on 4.7L engines is bolted directly

to the engine timing chain case cover.

(1) Clean gasket mating surfaces.
(2) Using a new gasket, position water pump and

install mounting bolts as shown. (Fig. 54). Tighten
water pump mounting bolts to 54 N·m (40 ft. lbs.)
torque.

(3) Spin water pump to be sure that pump impel-

ler does not rub against timing chain case/cover.

(4) Connect radiator lower hose to water pump.
(5) Relax tension from belt tensioner (Fig. 53).

Install drive belt (Refer to 7 - COOLING/ACCES-
SORY DRIVE/DRIVE BELTS - INSTALLATION).

Fig. 53 Automatic Belt Tensioner—4.7L

1 - AUTOMATIC TENSIONER
2 - WATER PUMP PULLEY

Fig. 54 Water Pump Installation—4.7L

1 - WATER PUMP
2 - TIMING CHAIN COVER

ENGINE

7 - 59

WATER PUMP - 4.7L (Continued)

Content .. 259 260 261 262 ..