(1) Inspect for cracks in housing and body.
(2) Inspect pump for damage or a blocked pump.
pump as follows:
(1) Drain the cooling system.
(1) Affix a new gasket to the water pump.
(2) Loosen hose clamp and remove hose.
(3) Remove bolt and remove pump cover.
(3) Fill the cooling system to proper level.
(4) Remove bolts and remove pump from blower.
(5) Remove and discard gasket.
Figure 4-16. Water pump, removal and installation.
shut down solenoid to close the shut down valve.
4-29. Engine Controls
4-30. Oil Pressure Switch
The automatic electrical shut-down system includes an oil
a. General. The oil pressure switch is located on the
pressure switch, a water temperature switch, a fuel
pressure switch and a shut down switch. The overspeed
left side of the engine above the by-pass oil filter (fig. 4-17).
governor switch can be employed separately or in
conjunction with the electrical shut-down system. When the
(1) Disconnect electrical wiring.
engine is not running, the fuel oil pressure switch is open,
(2) Disconnect fuel oil tubing.
the lubrication oil pressure switch is closed and the water
(3) Remove elbow, lock washers and hex nut and
temperature switch is open. After starting the engine, the
lubricating oil pressure switch contacts open when oil
pressure reaches 10 spi, and the fuel oil pressure switch
(1) Inspect for frayed or broken wiring.
contacts are closed when fuel oil pressure reaches 20 psi.
(2) Check for cracks or breaks in switch housing.
The water temperature switch is connected in parallel with
(3) Check connections and tubing for breaks,
the lubricating oil pressure switch and remains open unless
cracks or damage.
coolant temperature exceeds 200 + 5F. The shut down
(4) Replace defective parts.
solenoid would then be energized. The overspeed governor
d. Installation. Install the oil pressure switch in reverse
switch activates if engine speed exceeds the speed
order of removal.
established by the engine governor, causing the