LUBRICATING OIL PUMP, OIL FILTERS & COOLER
Inspect Oil Pressure Regulator Valve as follows:
Remove valve retaining plug from crank- case.
Move the regulator inner valve assembly (1, Fig.
13) to ensure it operates freely.
Inspect per Figures 13a and 13b.
Make sure that the snap rings (4 and 5, Fig. 13)
are in position and the inner valve spool has an
unobstructed 3.175 mm (0.125 in.) diameter bleed
hole (3, Fig. 13).
NOTE: This inspection can be performed without oil
pressure regulator valve disassembly.
Figure 13. - Oil Pressure Regulator Valve
Inner Valve Assembly
Outer Valve Assembly
3.175 mm (.125 in.) Bleed Hole
Large Snap Ring
Figure 13a. - Lube Oil Pressure Regulating Valve Check
Figure 13b. - Cross-Sectional View of Pressure
Regulating Valve Complete Assembly Check Points
NOTE: If conditions exist as shown in Figures 13a
and 13b and dimensions are not as specified replace
complete valve assembly.
Inspect and Repair Oil Drain Hole as follows:
Locate oil drain hole in the crankcase pressure
regulator valve bore (Fig. 14).
NOTE: The oil drain hole is an elliptical shaped port,
positioned in the lower radius of the bore. Three
oclock to six oclock on 400 Series engines and six
oclock to nine oclock on 300 Series engines.
Obstruction of the drain hole will result in excessive
oil pressure and possible oil filter rupture.
Figure 14. - Pressure Regulator Valve Bore (AE
Oil Pressure Regulator Valve Bore
Elliptical Drain Hole - approximately
12.7 mm (0.5 in.) X 6.3 mm (0.25 in.)
Oil Filter Base
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