SERVICE MANUAL
LUBRICATING OIL PUMP, OIL FILTERS & COOLER
Section 8
Depending upon the immediate conditions, the oil can
continue on in one of two directions or, in some
instances, divide and travel in both. During normal
operation, the flow of oil continues on through both filter
elements (14, Fig. 1) on its way back into the crankcase
main oil gallery. However, if the filters are not changed
per Operator’s Manual recommendations, excessive filter
contamination and pressure drop will result. When such
contamination occurs, the pressure differential type of
by-pass valve will open allowing the oil to by-pass the
filters and flow directly into the crankcase main oil gallery
where it is distributed to all parts of the engine.
OIL PRESSURE REGULATOR VALVE:
The unique design of the lubricating oil regulating valve
extends the life of the oil filters in that it controls the
volume and pressure of the filtered oil supplied to the
engine. The volume of oil supplied by the pump is in
excess of what is needed to lubricate the engine. This
valve divides that flow. The volume needed to lubricate
the engine is directed to the filters and excess is dumped
to return. When all points of lubrication within the engine
are satisfied, restriction to flow causes pressure to build
in the filtered oil gallery and on the face of the valve. As
this force moves the valve toward the regulator spring
the port in the unfiltered oil gallery is uncovered and
excess oil is dumped to return. Due to volume changes
caused by changes in engine RPM the valve will dump
more or less oil to the return keeping filtered oil pressure
and volume within the specified
range. Thus, the only oil filtered is that which is needed
to lubricate the engine.
Figure 6. - Oil Pressure Regulator Valve Operation
Oil Cooler:
The oil cooler is mounted on the right side of the engine.
All of the engine oil is circulated from the oil pump
through the cooler and into the oil filters. Water flows
from the radiator through numerous tubes in the oil
cooler.
CGES-185-3
PRINTED IN UNITED STATES OF AMERICA
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