International Harvester Company Cub Lo-Boy C-60 Service Manual page 56

Pressure Regulator Valve
Since the normal output of the oil pump is
much greater than the normal requirement
of the engine lubricating system, and all
the oil cannot escape through the engine
bearing clearances and metered passages,
a spring-loaded regulator valve is em-
ployed to release the excess oil. This
valve maintains an operating oil pressure
of 30 lbs. at 2200 rpm.
The free length of the valve spring will
give some indication of its condition. How-
ever, the best test to determine the
spring's tension is to load it with the
weight specified, and measure its length at
that load. If this tension test is found be-
low specifications the spring should be re-
placed or low oil pressure will continue.
The piston-type pressure regulator valve
and spring is located behind the hex-head
retaining plug on the right side of the
crankcase, near the timing gear end. The
valve should slide freely in the crankcase
bore and the spring should be straight so
that the valve will not be cocked in the bore
or on its seat.
During a complete engine overhaul, while
the engine is completely disassembled, all
oil passages should be cleaned, using
brass rifle brushes. Also, if crankshaft or
connecting rod bearings have failed due to
abrasives in the lubricating oil, the engine
must be completely disassembled and
thoroughly cleaned. Clean all, lubricating
oil passages, using rifle brushes and com-
pressed air. Clean and inspect the oil
pump and pressure regulator a~sembly and
service them as required.
Removal and Disassembly
If oil pressure is not within specifications,
the oil filter regulator valve, intake pipe
with screen, and the pump may be dis-
assembled as follows:
1. Remove filter element and clean
filter case. If filter case is exceptionally
sludgy, install bolt without cover and
flush thoroughly.
2. Remove hex-head regulator valve
retaining plug and remove the spring and
valve.
1. Plug
2. Spring
3.
Valve
3. Remove the crankcase oil pan. Re-
move the oil intake pipe and screen.
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FESM.3278