Chrysler Town & Country/Voyager, Dodge Caravan, Plymouth Voyager. Manual — part 182
COOLING SYSTEM DIAGNOSIS
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COOLING SYSTEM
7 - 9
SERVICE PROCEDURES
WATER PUMPS
A quick test to tell whether the pump is working is to
see if the heater warms properly. A defective pump can
not circulate heated coolant through the long heater
hose.
The water pump on all models can be replaced
without discharging the air conditioning system.
WATER PUMP 2.5L ENGINE
The 2.5L engine water pump has a diecast aluminum
body and housing with a stamped steel impeller. The
2.5L pump uses an O-ring gasket between body and
housing. The assembly bolts directly to the block.
Cylinder block to water pump sealing uses a rubber
O-ring.
REMOVAL
(1) Drain cooling system. Refer to Draining Cooling
System in this group.
(2) If equipped with air conditioning, see Solid
Mount Accessory Bracket in (Standard Service Proce-
dures) Group 9, Engine:
(a) Remove air conditioning compressor and alter-
nator from solid mount bracket and set aside. It is
not necessary to discharge the a/c system.
(b) Remove solid mount bracket.
(3) If the vehicle is not equipped with air condition-
ing, remove alternator and mounting bracket.
(4) Disconnect lower radiator and heater hoses from
pump.
(5) Remove water pump attaching screws to engine
(Fig. 1).
DISASSEMBLY
(1) Remove three screws holding pulley to water
pump.
(2) Remove nine screws holding water pump body to
housing. Remove the pump body from housing. (Fig. 2)
(3) Clean gasket surfaces on water pump housing
and engine block.
(4) Remove and discard O-ring gaskets and clean
O-ring grooves.
INSPECTION
Replace water pump body assembly if it has any of
these defects:
(1) Cracks or damage on the body.
(2) Water leaks from the shaft seal, evident by
coolant traces below the vent hole.
(3) Loose or rough turning bearing.
(4) Impeller rubs either the pump body or the hous-
ing.
ASSEMBLY
Body assembly and housing are serviced as separate
components.
(1) Install new O-ring gasket in body O-ring groove.
(2) Assemble pump body to housing and tighten nine
screws to 12 N
Im (105 in. lbs.) (Fig. 2).
(3) Rotate pump by hand to check for freedom of
movement.
(4) Position water pump pulley to water pump. In-
stall three screws and tighten to 30 N
Im (250 in. lbs.).
(5) Position new O-ring in housing to block O-ring
groove.
Fig. 1 Water Pump 2.5L Engines
Fig. 2 2.5L Water Pump Components
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COOLING SYSTEM
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INSTALLATION
(1) Install water pump on engine. Tighten top three
screws (Fig. 1) to 30 N
Im (250 in. lbs.). Install lower
screw and tighten to 68 N
Im (50 ft. lbs.).
(2) Reinstall bypass/heater hose and lower radiator
hose.
(3) Reinstall alternator and air conditioning com-
pressor bracket(s). For solid mount bracket see stan-
dard service procedures in Group 9 Engine.
(4) Reinstall alternator and air conditioning com-
pressor.
(5) Refill cooling system. See Refilling Cooling
System.
(6) Install drive belt, See Accessory Drive Belts, this
Group.
WATER PUMP 3.0L ENGINE
The 3.0L pump bolts directly to the engine block,
using a gasket for pump to block sealing (Fig. 3). The
pump is serviced as a unit.
The water pump is driven by the timing belt. See
Timing System in Group 9, Engine for component
removal providing access to water pump.
REMOVAL
(1) Drain cooling system. Refer to Draining Cooling
System in this group.
(2) Remove mounting bolts.
(3) Separate pump from water inlet pipe (Figs. 3 and
4) and remove.
INSPECTION
Replace the water pump if it has any of the following
defects.
(1) Damage or cracks on the pump body.
(2) Coolant leaks, if the shaft seal is leaking, evident
by traces of coolant leaks from vent hole A in (Fig. 4).
(3) Impeller rubs the inside of pump.
(4) Loose or rough turning bearing.
INSTALLATION
(1) Clean all gasket and O-ring surfaces on pump
and water pipe inlet tube.
(2) Install new O-ring on water inlet pipe (Fig. 5).
Wet the O-ring (with water) to ease assembly.
CAUTION: Keep the O-ring free of oil or grease.
(3) Install new gasket on water pump and install
pump inlet opening over water pipe, press assembly to
cause water pipe insertion into pump housing.
(4) Install pump to block mounting bolts and tighten
to 27 N
Im (20 ft. lbs.).
(5) See Timing System in Engine, Group 9 and
install timing belt. Reassemble engine.
(6) Fill cooling system. See Refilling Cooling System.
WATER PUMP 3.3L ENGINE
The 3.3L pump has a die cast aluminum body and a
stamped steel impeller. It bolts directly to the chain
case cover, using an O-ring for sealing. It is driven by
the back surface of the Poly-V Drive Belt.
Fig. 3 Water Pump 3.0L Engine
Fig. 4 Water Pump Inspection
Fig. 5 Water Pipe O-Ring
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COOLING SYSTEM
7 - 11
REMOVAL
(1) Drain Cooling System. Refer to Draining Cooling
System in this group.
(2) Remove Poly V Drive Belt.
(3) Remove right front lower fender shield.
(4) Remove pump pulley bolts and remove pulley.
(5) Remove pump mounting screws (Fig. 6). Remove
pump.
(6) Remove and discard O-ring seal.
(7) Clean O-ring groove and O-ring surfaces on
pump and chain case cover. Take care not to scratch or
gouge sealing surface.
INSPECTION
Replace the water pump if it has any of the following
defects.
(1) Damage or cracks on the pump body.
(2) Coolant leaks; if the seal is leaking, evident by
traces of coolant leaks from vent hole.
(3) Loose or rough turning bearing.
(4) Impeller rubs either the pump body or chain case
cover.
INSTALLATION
(1) Install new O-ring in O-ring groove (Fig. 7).
(2) Install pump to chain case cover. Torque screws
to 12 N
Im (105 in. lbs.)
(3) Rotate pump by hand to check for freedom of
movement.
(4) Position pulley on pump. Install screws and
torque to 30 N
Im (250 in. lbs.).
(5) Install drive belt. See Accessory Drive Belts this
group.
(6) Install right front lower fender shield.
(7) Refill Cooling System. See Refilling Cooling Sys-
tem.
ENGINE THERMOSTAT
The 2.5L engine thermostat is located on the front of
the engine (radiator side) in the waterbox that is part
of the cylinder head construction (Fig. 8).
These thermostats do not have an air bleed notch.
The 3.0L engine thermostat is in a water box, formed
in the timing belt end of the intake manifold. This
thermostat has an air bleed valve, located in the
thermostat flange (Fig. 9).
The 3.3L engine thermostat is in a water box, formed
in the drive belt side of the intake manifold (Fig. 11).
DESCRIPTION AND OPERATION
The engine cooling thermostats are wax pellet
driven, reverse poppet choke type. They are designed
to provide the fastest warm up possible by preventing
leakage through them and to guarantee a minimum
engine operating temperature of 88 to 93°C (192 to
199°F). They also automatically reach wide open so
they do not restrict flow to the radiator as temperature
of the coolant rises in hot weather to around 104°C
(220°F). Above this temperature the coolant tempera-
ture is controlled by the radiator, fan, and ambient
temperature, not the thermostat.
OPERATION AND TESTING
The thermostat operateds by a wax filled container
(pellet) that is sealed so that when heated to a prede-
termined temperature. The wax expands enough to
overcome the closing spring and water pump pressure,
which forces the valve to open. Coolant leakage into the
pellet will cause a thermostat to fail open. Do not
attempt to free up a thermostat with a screwdriver.
The open too soon type failure mode is included in
the on-board diagnosis. The check engine light will not
be lit by an open too soon condition. Only if the
thermostat has failed open, a code 17 will be set. Do not
change a thermostat for lack of heat by gauge or heater
performance, unless code 17 is present, see diagnosis
for other probable causes. Failing shut is the normal
long term mode of failure, and normally, only
Fig. 6 Water Pump 3.3L Engine
Fig. 7 Water Pump Body
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COOLING SYSTEM
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