Chevrolet 70 1969 Series, Shop Manual

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6V-53 DIESEL ENGINE 6C-10
cooler and back into the front engine cover and
cylinder block oil galleries for distribution to var­
ious engine bearings. The oil drains from the cyl­
inder head and other engine parts back to the oil
pan.
A replaceable element-type full-flow filter
installed between the oil pump and oil cooler, filters
the oil prior to entering the engine. If filter be­
comes restricted, the oil will flow through a by­
pass valve, which opens at 18 to 21 psi, directly
to the cooler.
The oil cooler by-pass valve is located on the
right side of the engine front cover and the oil
pressure regulator valve is located on the left side
as viewed from the rear of the engine.
If oil cooler becomes restricted, the oil flow
will be to a by-pass valve in lower engine front
cover, then to the cylinder block oil galleries. The
by-pass valve opens at approximately 52 psi.
Stabilized lubricating oil pressure is main­
tained within the engine at all speeds by means of
a regulator valve located in the lower front engine
cover. The regulator valve, located in the pump
outlet passage, opens at approximately 52 psi and
returns excess oil directly to the crankcase.
All crankshaft and connecting rod bearings
are pressure lubricated. Oil passages branching off
from the main oil gallery direct the oil to camshaft
end bearings, idler gear and accessory drive gear
bearings, blower, and cylinder heads.
Oil for lubricating connecting rod bearings,
piston pins, and for cooling the piston heads is
provided through the drilled crankshaft from the
adjacent forward main bearings. The gear train is
lubricated by the overflow of oil from the camshaft
pocket through a passage into the flywheel housing.
CHEVROLET SERIES 70 -80 H EAVY DUTY TRUCK SH O P M A N U A L