Lycoming YO-233-B2A - Page 101

TEO-540-A1A Engine Maintenance Manual
© 2021 Avco Corporation. All Rights Reserved 12-30
February 2021 Page 81
YO-233-B2A Engine Maintenance Manual
Table 1 (Cont.)
Fault Isolation Guide
Problem
Cause
Corrective Action
Ref.
Irregular or low oil
pressure
Low engine oil level
Complete a check of the oil
level. Add oil.
12-10
Air leaks
Look for air leaks at the oil
sump gasket.
Pressure relief is out of
adjustment
Increase the oil pressure by
turning the adjusting screw
counterclockwise.
72-50
Dirt or metal chips under
the oil pressure relief
valve
Remove, disassemble, and clean
the oil pressure relief valve
OHM
Damaged oil pressure
relief seat
Replace or repair the oil
pressure relief seat
OHM
Blockage at inlet side of
oil pump
Remove and clean the oil
suction screen and oil passage to
the inlet side of the oil pump.
12-10
Too much internal oil
spill-off
Examine these area:
— Loose or missing plugs
in oil galley
— Piston cooling squirts
are blocked open (at idle
rpm)
— Too much bearing
clearance
— Cracked crankcase in the
oil galley area
OHM
Air leak on suction side
1. Examine the conditions of
these components:
— Oil suction screen
— Oil sump gasket
— Oil pump mating surface
to accessory housing
2. Replace cracked or damaged
parts.
OHM