Mitsubishi S12U User Manual

Chapter 5 PERIODIC MAINTENANCE CHART
5-5
Every 12000
service
hours
Overhaul of top end of engine (remove the cylinder heads for inspection and main-
tenance.)
½
Cylinder
heads and
valve mech-
anisms
Disassemble and maintain, clean and change expendable parts.
Valve seat Inspect, regrind and lap.
Cylinder head
gasket
Change.
Copper tubes Change copper tubes and O-rings.
Inlet and
exhaust valves
Inspect, regrind and lap.
Valve guides,
valve rotator,
valve cotter,
pushrods,
rocker arm
bushings, valve
springs, tappet
rollers, tappet
roller bushing,
tappet shafts,
tappet guides,
tappet guide
set screws.
Inspect.
Stem seal Change.
Safety valve Inspect and change expendable parts.
Cylinder liners Inspect and clean.
Pistons Inspect including overhaul and clean.
Piston rings Change.
Connecting rods
Inspect bolts, inspect Magnaflux serrations,
change big-end bearing shells and inspect small-
end bushings.
Crankshaft Inspect and adjust deflection.
Damper
Analyze silicon oil properties and change thermo
label.
Front gear and timing gear Inspect gear teeth.
Table 5-1 Periodic maintenance chart for engine in regular use (3 / 5)
Service
interval
Service item Service contents Page

Mitsubishi S12U Specifications

General

Brand	Mitsubishi
Model	S12U
Category	Engine
Language	English