Dodge RAM TRUCK 1500 1995 Service Manual page 288

7 -18 COOLING SYSTEM SERVICE PROCEDURES
B R
S E R V I C E P R O C E D U R E S
INDEX
page
Coolant 37
Coolant Reserve/Overflow System 41
Cooling System Cleaning/Reverse Flushing 39
Cooling System Fan—Diesel Engine 47
Cooling System Fan—Gas Engines . . . . . . . . . . . . 46
Cooling System Hoses 45
Draining Cooling System . 38
Radiator Pressure Cap . 42
Radiators 43
WATER PUMPS—EXCEPT DIESEL AND 8.0L V-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 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 an­
tifreeze in the coolant mixture. Additional lubrication
is not necessary.
A quick test to determine if pump is working is to
check if heater warms properly. P. defective water
pump will not be able to circulate heated coolant
through the long heater hose to the heater core.
MEMOWAl
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 3.9L/5.2L/5.9L gas powered engines, a gas­
ket 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 fa­
tigue 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 Viscous
Fan Drive in this group.
(1) Disconnect negative battery cable from battery.
(2) Drain cooling system. Refer to Draining Cooling
System in this group.
Do not waste reusable coolant. If solution is clean,
drain coolant into a clean container for reuse.
page
Refilling Cooling System 38
Testing Cooling System for Leaks 40
Thermostat 30
Viscous Fan Drive . . . . . . . . . . . . . . . . . . . . . . . . . 48
Water Pump Bypass Hose . . . . . . . . . . . . . . . . . . 26
Water Pump—5.9L Diesel 25
Water Pump—8.0L V-10 Engine . . . . . . . . . . . . . . 21
Water Pumps—Except Diesel and 8.0L V-10
Engine 18
(3) Remove windshield washer reservoir tank from
radiator fan shroud. Refer to Group 8K, Windshield
Wiper and Washer Systems.
(4) Disconnect the coolant reserve/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 MOUNTING BOLTS J9407-37
Fig. 1 Typical Fan Shroud Mounting
W A R N I N G : CONSTANT T E N S I O N HOSE C L A M P S
ARE U S E D ON HOST C O O L I N G SYSTEM HOSES.
W H E N R E M O V I N G OR I N S T A L L I N G , USE ONLY
T O O L S D E S I G N E D FOR S E R V I C I N G THIS T Y P E O F
CLAMP
S
SUCH AS SPECIAL C L A M P TOOL (NUMBER
6094) ( F I G . 2). S N A P - O N C L A M P TOOL ( N U M B E R
H P C - 2 0 ) M A Y B E U S E D F O R L A R G E R CLAMPS. AL­
W A Y S W E A R S A F E T Y G L A S S E S WHEN SERVICING
C O N S T A N T T E N S I O N CLAMPS.