Pressure Relief Valve - Generac Power Systems OHVI GSH 220 Service Manual

OIL PUMP
INNER ROTOR
Figure 9-5. Oil Pump
INSPECTION:
. Inspect the inner and outer rotors for damage and wear
(Figure 9-6).
2. Use a feeler gauge to check tip clearance of inner rotor,
with rotor installed on shaft in crankcase cover.
. Measure the bore inner diameter of the inner rotor.
. Measure the inner rotor thickness.
5. Check the outer rotor outside diameter.
6. Inspect the outer rotor drive pins on the camshaft. Check
for breaking, bending or other damage. The two roll pins
can be removed and replaced with relative ease.
Replace any oil pump component that is damaged or worn
excessively.
NOTE: The shaft on which the inner oil pump rotor
rotates is NOT replaceable. If the shaft is damaged or
worn, the crankcase cover must be replaced.
Tip Clearance of Rotor
Rotor Thickness
Figure 9-6. Inner and Outer Rotor Check Points
OIL PUMP
OUTER ROTOR
CAMSHAFT
Inner Rotor I.D.
Outer Rotor O.D.
9-
SeCTIoN 9: lubrICATIoN SYSTeM

PreSSure relIeF vAlve

DESCRIPTION:
A ball type pressure relief valve is located in a bore of the
crankcase cover (see Figure 9-7). The valve serves to limit oil
pressure to a maximum value. The ball will remain against its
seat as long as oil pressure is below about 0 psi (on Large
Frame engines) or 0 psi (on Small Frame engines). Should oil
pressure increase above that value, the ball will be forced off
it's seat to relieve excess oil pressure into the crankcase. The
ball and spring are held in place by a retainer.
INSPECTION:
Remove the SCREW that retains the RETAINER to the crank-
case. Remove the RETAINER, SPRING and BALL (Figure 9-7).
Clean all parts in solvent.
Inspect the BALL and RETAINER for damage, wear. Replace
any damaged or worn part. Inspect the SPRING, replace if
damaged or worn.
Measure the free length of the oil pressure relief valve spring.
Replace the spring if it is not the proper length. Refer to the
SPECIFICATIONS section at the back of this manual for proper
spring dimensions.
1. SCREW
2. RETAINER
3. SPRING
4. BALL
4
3
2
1
Figure 9-7. Oil Pressure Relief Valve
9