Advertisement
7-4
COOLING SYSTEM
\
1
NK480
\
PULLEY
f
SPACER
NY 72 B
Fig. 1-Standard
Fan Drive
Fig. 2--Torque
Control Fan Drive
fluid filled coupling connecting the fan to the fan pul-
ley. The unit allows the fan to be driven in a normal
manner at slow vehicle speeds while limiting the top
speed of the fan to a pre-determined level.
Thermal Control Drive
The Thermal Control Drive (Fig.
3)
is essentially
the same as the Torque unit except for a thermal
spring on the drive face. The thermal spring senses
the heat from the radiator and engages the drive for
normal fan operation when required.
In case of engine overheating during slow vehicle
speed or idle operation, increase the engine speed
to approximately
1000
rpm in neutral gear. If the con-
dition is not corrected by increasing the engine speed,
replace the fan drive unit with a unit known to be op-
erating properly and test by operating the vehicle
under the same conditions. Replace the original drive
unit assembly
if
the trouble was corrected with the
test unit.
NK479
Fig. 3--Thermal
Control Fan Drive
WATER PUMP
Removal
(1) Drain the cooling system and remove the fan
shroud (air conditioning equipped vehicles). Loosen
the fan drive belt by loosening the alternator mount-
ing bracket and swing the alternator in towards the
water pump (on vehicles equipped with air condition-
ing, loosen the idler pulley).
(2)
Remove the fan, spacer and pulley.
(3) Remove the water pump to housing retaining
bolts and washers and remove the water pump from
the vehicle. Discard the gasket.
Installation
(1)
Use a new gasket and install the water pump.
Tighten the bolts to 30 foot-pounds.
(2)
Install the pulley spacer, fan and shroud (when
so equipped).
Fill the cooling system and
test
for leaks.
Test the belt tension as outlined in "Accessory Belt
Drives."
Disassembly
( I
70,225
cubic inch engines)
(Fig.
41.
the metal insert.
(1)
Break the plastic impeller and remove it from
(2)
Remove the separator plate and gasket.
(3)
Split the sintered metal insert of the plastic im-
(4)
Remove the rubber portion of the shaft seal
(5) Using puller Tool C-3753 (Fig.
5)
remove the
(6)
Remove the fan hub using puller Tool
C-412.
(7) Support the pump body on the front face (fan
hub end) and apply pressure to the rear end of the
shaft to press the shaft and bearing assembly out
through the front of the pump. If an attempt is made
to remove the shaft in the opposite direction damage
to the pump body may result.
peller with a chisel and hammer.
and the spring.
retainer portion of the seal.
Hide quick links:
Advertisement
