SERVICE MANUAL
WATER PUMP, THERMOSTAT & IDLER PULLEYS
Section 9
WATER PUMP
The belt-driven centrifugal pump is built into the front
cover but can be removed when service is necessary.
Water Inlet and outlet passageways are cast into the
cover.
Coolant from the lower tank of the radiator enters the
front cover near the bottom and flows to the center of the
pump Impeller through the upper channel. Upon leaving
the Impeller, the coolant enters the lower channel which
divides the flow. Part of the flow travels Pack down to
the lower end and enters the oil cooler as shown in figure
one. After flowing through the cooler, It re-enters the
upper channel to mix with the incoming coolant from the
radiator.
The other part of the pump flow enters the distribution
passageway cast In the crankcase. The passageway
directs coolant from the front to the rear of the
crankcase, evenly distributing the coolant, to the lower
sections of each cylinder sleeve. The coolant enters
each sleeve chamber on a tangent causing It to swirl
around the sleeve as it travels upward and into the head.
This swirling of the coolant aids In preventing sludge and
rust
accumulations,
which
greatly
reduce
cooling
efficiency.
Coolant directors (2, Fig. 2) in the cylinder head water
passages direct the coolant for scrubbing the valve seat
areas and nozzle tubes, as shown. Two air bleed holes
(1) vent the crankcase into the cylinder head coolant
passages.
The coolant flowing out of the cylinder head enters the
thermostat housing. Here the coolant Is either directed
to the radiator If at operating temperature or directed
back to the pump if not at operating temperature.
Figure 2. - Coolant Passages In Cylinder Head and Crankcase
1. Air Bleed Holes
2. Coolant Director
CGES-185-3
PRINTED IN UNITED STATES OF AMERICA
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