TM 5-3805-263-14&P-3
CLEANING AND INSPECTION
DISCHARGE VALVES AND SEATS
If discharge valves are worn and grooved where they
OF PARTS
contact the seats, they should be replaced. If the
CLEANING
discharge valve seats are worn excessively so that there
All parts should be cleaned thoroughly in a good cleaning
is no longer enough metal left to reclaim them by
solvent before inspection.
lapping, the seats should be replaced.
CYLINDER HEAD ASSEMBLY
DISCHARGE VALVE SPRING AND CAP NUTS
Remove all carbon deposits from discharge cavities and
Replace all used discharge valve springs and cap nuts.
all rust and scale from cooling cavities of cylinder head
body.
CRANKCASE AND END COVER
Check for cracks or broken lugs in crankcase and end
Scrape all foreign matter from body surfaces and use air
cover. Also check their oil passages to make sure they
pressure to blow dirt particles from all cavities.
are open and clean.
Discharge valves can be dressed by lapping them on a
Check fit of the oil seal ring in ring groove of the end
piece of fine crocus cloth on a flat surface, provided they
cover. There should be 0.008 in. to 0.015 in. clearance at
are not excessively worn.
the gap when placed in the end bore of the crankshaft. If
the oil ring is worn thin or is damaged, it should be
CYLINDER BLOCK
replaced. Inspect oil ring groove in end cover; if groove is
Clean carbon and dirt from inlet and unloader passages.
worn excessively replace end cover.
Use air pressure to blow carbon and dirt deposits from
unloader passages.
CYLINDER BLOCK
Check for cracks or broken lugs on cylinder block. Also
Inlet valves, as in the case of discharge valves, not worn
check unloader bore bushings to be sure they are not
excessively, can be cleaned by lapping them on a piece
worn, rusted or damaged. If these bushings are to be
of fine crocus cloth on a flat surface.
replaced they can be removed by running a 1/8 in. pipe
thread tap inside the bushing, then inserting a 1/8 in.
OIL PASSAGE
pipe threaded rod and pulling the bushing straight up and
Clean thoroughly all oil passages through crankshaft,
out. Do not use an easy-out for removing these
connecting rods, crankcase, end covers and base plate.
bushings.
If necessary inspect passages with a wire and blow
foreign matter out with air pressure.
INLET VALVES AND SEATS
If inlet valves are grooved or worn where they contact the
INSPECTION OF PARTS CYLINDER HEAD BODY
seat, they should be replaced. If the inlet valve seats are
Inspect cylinder head body for cracks or damage.
worn or damaged so they cannot be reclaimed by facing,
they should be replaced.
Use air pressure to test water jackets of cylinder head
and block for leakage. Replace unit if leakage is found.
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