Dodge ram truck 3500 1996 Service Manual page 323

B R COOLING SYSTEM 7 - 31
R E M O V A L A N D I N S T A L L A T I O N ( C o n t i n u e d )
AUTOMATIC
TENSIONER
RADIATOR
FAN
SHROUD
J9307-56
Fig, 49 Beit Routing—5.9L HDC-Gas Engine—
Without A/C
fatigue 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 in this group.
(1) Disconnect negative battery cable from battery.
(2) Drain cooling system. Refer to Draining Cool­
ing System in this group.
Do not waste reusable coolant. I f solution is clean,
drain coolant into a clean container for reuse.
(3) Remove windshield washer reservoir tank from
radiator fan shroud. Refer to Group 8K, Windshield
Wiper and Washer Systems.
(4) Remove the four fan shroud mounting bolts at
the radiator (Fig. 50). 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) (Fig. 23). SNAP-ON CLAMP TOOL (NUMBER
HPC-20) MAY BE USED FOR LARGER CLAMPS.
ALWAYS WEAR SAFETY GLASSES WHEN SERVIC­
ING CONSTANT TENSION CLAMPS.
CAUTION: A number or letter is stamped into the
tongue of constant tension clamps (Fig. 24). If
replacement is necessary, use only an original
equipment clamp with a matching number or letter.
FAN SHROUD M O U N T I N G BOLTS J9407-37
Fig. 50 Typical Fan Shroud Mounting
(5) Remove upper radiator hose at radiator.
(6) The thermal viscous fan drive is attached
(threaded) to the water pump hub shaft (Fig. 51).
Remove the fan/fan drive assembly from water pump
by turning the mounting nut counterclockwise (as
viewed from front). Threads on the fan drive are
EIGHT-HAND, A Snap-On 36 M M Fan Wrench
(number SP346 from Snap-On Cummins Diesel Tool
Set number 2017DSP) can be used. Place a bar or
screwdriver between the water pump pulley bolts
(Fig. 51) to prevent the pulley from rotating.
(7) I f water pump is being replaced, do not unbolt
fan blade assembly (Fig. 51) from the thermal control
fan drive.
(8) Remove fan blade/fan drive and fan shroud as
an assembly from vehicle.
After removing fan blade/fan drive assembly, do
not place the thermal viscous fan drive in the hori­
zontal position. I f stored horizontally, the silicone
fluid in the viscous drive could drain into its bearing
assembly and contaminate the bearing lubricant.
Do not remove the water pump pulley bolts at this
time.
(9) Remove accessory drive belt as follows: The
drive belt is equipped with a spring loaded automatic
tensioner (Fig. 52).
Relax the tension from the belt by rotating the ten­
sioner counterclockwise (as viewed from front) (Fig.
17). The threads on the pulley bolt are left-hand.
When all belt tension has been relaxed, remove
accessory drive belt.