TM 9-2320-387-24-l
REFERENCE INFORMATION
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. .
ENGINE COOLING
I SURGE COOLANT
TANK FILLER
SURGE
I
CAP
TANK
WARNING
Do not remove surge tank filler
cap before releasing
internal
pressure
when engine temperature
is above
IW’F
(WC).
Steam or hot coolant
under pressure
will cause injury.
Check seal and spring on pressure cap.
Replace pressure cap (para. 361).
-
i
Flush cooling system (para. 3-61).
For surge tank and radiator support replacement
procedures, refer to paras. 3-64 and 3-65.
For oil cooler and oil cooler hose replacement
procedures, refer to paras. 3-7 and 3-6.
Notify DS maintenance to repair radiator
(chapter 17).
- :
ENGINE COOLING FAN DESCRIPTION OF OPERATION
An external line from the power steering gear brings hydraulic fluid to the clutch fan solenoid through
i
control valve (normally open) and then to the fan drive. keeping it disengaged. The action of the valve
is controlled by the time-delay module and the fan temperature switch.
During normal operation, the fan timer switch is closed. This keeps the control valve in the
open position and the drive disengaged.
As the engine reaches a temperature of about 215°F (102%). the temperature switch opens and the
control valve closes. This engages the fan. If the fan is engaged and the accelerator is floored, the
throttle position sensor disengages the fan drive for a period of 20 seconds.
The easiest way to determine if the fan is engaged is to stand outside the drivers door and gently
work the accelerator.
If the fan is engaged, you will feel a breeze from the engine area. If the fan is
not engaged, you won’t feel the breeze.
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