Chrysler RAM TRUCK 2500 1994 Service Manual page 271

7 - 11 COOLING SYSTEM
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SERWiCE P R O C E D U R E S
INDEX
page
Coolant 34
Coolant Reserve/Overflow System 39
Cooling System Cleaning/Reverse Flushing 36
Cooling System Fan—Diesel Engine 45
Cooling System Fan—Gas Engines 43
Cooling System Hoses 43
Draining Cooling System 36
Radiator Pressure Cap 40
Radiators 41
WATER PUMPS—EXCEPT DIESEL AND 8.0L ¥-10
ENGINE
A 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
drive belt.
The water pump impeller is pressed onto the rear
of a shaft that rotates i n a bearing pressed into the
water pump body. The body has a small hole for ven­
tilation. The water pump seals are lubricated by an­
tifreeze i n the coolant mixture. Additional lubrication
is not necessary.
A quick test to determine i f pump is working is to
check i f 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 all gas powered engines except the 8.0L V-10, a
gasket is used as a seal between the water pump and
timing chain case/cover.
I f water pump is replaced because of bearing/shaft
damage or leaking shaft seal, the mechanical cooling
fan assembly should also be inspected. Inspect for fa­
tigue cracks, loose blades or loose rivets that could
have resulted from excessive vibration. Replace fan i f
any of these conditions are found. Also check condi­
tion of the thermal viscous fan drive. Refer to Viscous
Fan Drive i n this group.
(1) Disconnect negative battery cable from battery.
(2) Drain cooling system. Refer to Draining Cooling
System i n this group.
Do not waste reusable coolant. I f solution is clean,
drain coolant into a clean container for reuse.
page
Refilling Cooling System 36
Testing Cooling System for Leaks 37
Thermostat 28
Viscous Fan Drive 45
Water Pump Bypass Hose 24
Water Pump—5.9L Diesel 23
Water Pump—8.0L V-10 Engine 19
Water Pumps—Except Diesel and
8.0L V-10 Engine
16
(3) Remove windshield washer reservoir tank from
radiator fan shroud. Refer to Group 8K, Windshield
Wiper and Washer Systems.
(4) Except 8.0L V-10: Disconnect the coolant re­
serve/overflow tank-to-radiator hose at the tank.
(5) Remove the four fan shroud mounting bolts at
the radiator (Fig. 1). Do not attempt to remove
shroud from vehicle at this time.
RADIATOR
FAN SHROUD M O U N T I N G BOLTS J9407-37
Fig. 1 Typical Fan Shroud Mounting
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 A S SPECIAL CLAMP TOOL (NUMBER
60§4) (FIG. 2). SNAP-ON CLAMP TOOL (NUMBER
HPC-20) MAY BE USED FOR LARGER CLAMPS. A L ­
WAYS WEAR SAFETY GLASSES WHEN SERVICING
CONSTANT TENSION CLAMPS.