z. The Engine Coolant Pump (Fig. 22).
The centrifugal pump
mounts on top of the oil cooler housing. An impeller presses on one
end of the pump shaft and the pump drive pulley presses on the
A sealed, double row, combination radial and thrust
ball bearing supports the pump shaft.
A seal prevents coolant from
leaking along the shaft toward the bearing.
The shaft and bearing
are an assembly, and serviced as such. The sealed coolant pump shaft
bearing is filled with lubrication at assembly, therefore no
requirement for further lubrication exists.
aa. The Engine Thermostat (Fig. 23).
A single blocking
thermostat, located in a housing attached to the water outlet of the
left hand cylinder head, automatically controls the temperature of
the engine coolant. A crossover tube connects the thermostat housing
to the right hand cylinder head. If the temperature of the coolant
is below 170F, the thermostat stays closed and blocks the flow of
coolant to the radiator.
During this period, the coolant flows
the coolant pump using the bypass tube.