Yanmar 3JH4BE - Lube Oil Pump Inspection; Oil Pressure Control Valve Construction

8. LUBRICATION SYSTEM
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8.2.4 Lube oil pump inspection
(1) Outside clearance of outer rotor
Insert a gap gage between a outer rotor and a pump body,
and measure the clearance.
(2) Side clearance of outer rotor
When measuring a side clearance, put a right-angle gage
to the pump body, insert a gap gage and measure the
clearance.
(3) Inner rotor and gear boss clearance
8.2.5 Oil pressure control valve construction
The oil pressure control valve attached with lube oil pump controls the oil pressure from the time the lube
oil leaves the filter and is cooled in the lube oil cooler until just before it enters the cylinder body main
gallery.
When the pressure of lube oil entering the cylinder body main gallery exceeds the standard, the control
valve piston opens the bypass hole and lube oil flows back into the oil pan.
Outside clearance mm
Standard Limit
0.12-0.21 0.30
Side clearance mm
Standard Limit
0.02-0.07 0.12
Item Part
Standard
dimension
(mm)
Standard
clearance
(mm)
Standard
clearance limit
(mm)
Inside clearance of inner
rotor
Gear boss diameter 53.05-53.15
0.3-0.5 0.6
Rotor inner diameter 53.45-53.55
Width across flat
clearance of inner rotor
Width across flat of gear
boss
49.45-49.75
0.2-0.6 0.7
Width across flat of rotor 49.95-50.05
Standard oil pressure
0.39-0.54 MPa
(4.0-5.5kgf/cm
2
)
(Outer diameter clearance)
Outer roto
r
Gear case
(Side clearance)
Rotor inne
r
diameter
Crank gear
Inner rotor
Width across
flat of rotor