TM 5-3810-288-12
(c) Remove
water
pump
line
nuts
and
(d) Remove water pump line and pump line gasket.
(e) Remove thermostat housing and gasket.
(f) Remove thermostat. Do not disassemble
further unless base gasket must be replaced.
(3) Testing. Test the thermostat for proper operation
by suspending it and a thermometer in a container of
water. Heat the water. When the thermometer indicates
between 160 and 165 degrees Fahrenheit, the thermostat
should begin to open. It should be fully open when the
temperature has risen to between 185 and 190 degrees
Fahrenheit. Remove the thermostat from the water when
it is fully open. The cool surrounding air should now
cause the thermostat to dose rapidly. Replace a defective
thermostat.
(4) Repair. No repair of a faulty thermostat is
possible. It must be replaced. Replace all gaskets when
disassembly has occurred. Replace faulty hoses or hose
clamps.
thermostat housing, and lines.
d. Water Pump. Drain the coolant system be- low
the level of the water pump before removing the pump.
Refer to figure 3-47 and remove the radiator. Refer to
Figure 3-34. Engine speed governor, removal and
can be removed from the water pump sheaves. Refer to
replacement
clean with a damp cloth. Keep the petcock (fig.
e. Water Pump Drive Belt. The water pump drive
3-48) closed.
belts also drive the alternator. Refer to paragraph 3-49 for
(2) Removal. With the engine stopped, open
information on water pump drive belt adjustment or
the petcock, figure 3-48, and drain coolant below the
replacement.
level of the thermostat. Refer to figure 3-47 and
remove the upper connection hose attached to the top
f. Water Temperature Sender. Refer to figure 3-50
of the thermostat housing. Then proceed as follows:
and replace a faulty water temperature sender.
(a) Remove bolts and lockwashers which
3-49. Electrical System
secure the thermostat housing to the base (fig. 3-48).
a. General. This machine uses 24 volt compon-
Note that the Oildex filter will be removed from its
ents. Refer to figure 1-14 for a view of the electrical
mounting on the thermostat housing by removing
system schematic diagram. The system consists of two
these bolts. Refer to figure 3-28.
12 volt batteries, a magnetic switch, an alternator with
internal voltage regulator, the starter motor, and other
(b) Remove the clamp which secure the
minor components as shown on the schematic diagram.
water pump line to the thermostat housing.
The system is of the negative ground type.
3-41
