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11-8
_ _ _ _ _ 6·/,8: _ _ _ .....
6·14~
1 - - - - - - 5·70''
- - - o - i
·050"
• THIS DIMENSION
·030""
MUST BE-MAINTAINED
FROM EXTREME SURFACE
OF IMPELLER
FIG.
10-302-351
VB Water
Pump Assembly Dimensions
302-351
WATER PUMP OVERHAUL
DISASSEMBLY
1. Position the pump on an arbor
press and press the hub off the shaft.
2. Press the shaft and impeller and
the seal assembly out of the housing
using a cylindrical support.
NOTE:
The impeller cannot be separated
from the shaft without damage to the
ceramic seal face and a new ceramic
seal must be fitted should the
impeller be removed.
Should a steel impeller be fitted,
pressure may only be applied to
sleeve of the impeller.
ASSEMBLY
1. Apply a light film of water-
proof sealer on a new seal and press
the seal into the housing.
2. Coat the outer ·diameter of the
bearing lightly with grease, and press
the shaft and bearing into the pump
housing. Press the shaft and bearing
into the housing until the bearing is
flush with the housing hub.
3. Carefully press the ceramic-
faced seal onto the shaft approxi-
mately!-"-
GROUP
11- COOLING SYSTEM
FIG.
11
-Water Pump Removal
CAUTION
Do not allow oil or grease to
contact the ceramic seal face.
4. Position the impeller on the
shaft and press impeller and ceramic
seal on to shaft until a dimension of
6.138/6.146 is obtained from the
pulley end of the shaft to the
extremity of the impeller (Fig. 10).
5. Position the pulley hub on the
shaft and press on until a dimension
of 5.70" is obtained from the hub
face to the housing mounting face.
(Fig. 10).
FAN DRIVE CLUTCH
DESCRIPTION
The fan clutch (Figs. 12, 13 and 14)
permits use of a powerful fan without
paying the penalty of power loss or
noise. The fan clutch is a mechanical
device which provides maximum air
flow through the radiator when re-
quired, and a minimum air flow when
less than maximum cooling is neces-
sary
.
It can modulate between the
maximum and the minimum air flows
according to conditions, and it limits
fan speed to a maximum rpm, beyond
a given engine input speed
.
The viscous fluid shear principle in
general is applied to fan clutch design
in the following manner
:
A drive plate totally enclosed with-
in the clutch housing is attached di-
rectly to the clutch input shaft (as-
sembled to the water pump shaft and
pulley).
A
predetermined clearance
between the drive plate and the inner
surfaces of the clutch housing is es-
tablished -at assembly
.
The clutch housing and the fan
blade assembly are mounted to the
input shaft by a sealed bearing and
are free to rotate independently of the
drive plate and input shaft.
The interior chamber of the clutch
housing is filled with a given amount
of silicon base oil. Centrifugal force
resulting from the rotation of the
clutch. coupled with the constant
pumping action designed into the unit
forces the silicon base oil evenly
about the inner surfaces of the clutch
in the close clearance or drive area
.
The drag between the driving and the
driven members is thus increased by
the presence of the oil, causing the
clutch action.
A control valve (operated by a te-
rn perature-sensitive bi-metal coi I or
strip in the air stream on the front of
the clutch) regulates the amount of oil
pumped in or out of the close clear-
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