Service and Parts Manual - Cummins Onan

HEX HEAD
CAP SCREW ,a
I
OIL PUMP IN
CRANKCASE TURN
ON LEFT SIDE-
UNSCREW OIL PUMP
FROM INTAKE CU
To reassemble revers
OIL PUMP ASSEHB .L
.,,A /
FIGURE 4. OIL PUMP ASSEMBLY
Check the oil pump thoroughly for worn parts. Oil the
pump to prime it before reinstalling. Except for gaskets
and suction cup, the component parts of the pump are
not available individually. Install a new pump assembly
if required.
WASHER .-
A
. cfJ REEDVALVE
ATHER BAFFLE
GASKET HAS A
CORRECTWAY AND
AN INCORRECT WAY
TO INSTALL. CHECK
CLOSELY FOR PROPER
ElTl
If new oil pump gaskets are installed, they should be
the same thickness as those removed. A gasket kit with
various thickness gaskets is available.
OIL BY-PASS VALVE
The by-pass valve (located to the right and behind gear
cover), controls oil pressure by allowing excess oil to
flow directly back to the crankcase. Normally the valve
begins to open about 3Opsi.
The valve is non-adjustable and normally does not need
maintenance. To determine if valve is not working
' correctly, caused by a sticky plunger, inspect as
follows:
1. Remove 3/8 x 24 x 1 cap screw located behind gear
cover and under governor ann.
2. Remove spring and plunger with a magnet tool.
Clean plunger and spring with a suitable solvent
and reinstall.
FIGURE 3. CRANKCASE BREATHER
c
PRESSURE LUBRlCATlON
Pressure lubricated engines use an oil pump to lubricate
engine parts. If oil pressure is low, the pump
should be checked.
To remove the oil pump, it is necessary to detach the
intake cup assembly, as illustrated in Figure 4.
7