TM 5-4310-352-14
than a slight discoloring, the cylinder has not been prop-
c
Cleaning, Inspection and Repair.
erly cleaned.
(1) Thoroughly clean the air heads by brushing
(7) Wash the oil reservoir portion of the frame,
or scraping lightly to remove accumulations of carbon
being sure that accumulations of oil and sludge are re-
deposits, being careful not to damage gasket surfaces. Be
moved. Clean gasket surfaces for cylinders and end cov-
sure the gasket surface is free of all gasket particles.
ers. Be sure no particles of old gaskets remain on the
WARNING
surfaces.
Dry cleaning solvent, P-D-680, used to clean
WARNING
parts is potentially dangerous to personnel
Dry cleaning solvent, P-D-680, used to clean
and property. Do not use near open flame or
parts is potentially dangerous to personnel
excessive heat. Flash point of solvent, is
and property. Do not use near open flame or
100 (38 ) - 138 (59 ).
F
C
F
C
excessive heat. Flash point of solvent is
(2) Use solvent Fed Spec P-D-680 and wash
100 (38 ) - 138 (59 ).
F
C
F
C
away all accumulated oil. Be sure bore of cylinder is
(8) Clean the air valves in solvent Fed. Spec.
clean, and that all gasket particles are removed from
P- D-680. Clean both valve and seat by brushing with a
surfaces to be gasketed.
stiff bristle (not wire) brush. Should it be necessary to
(3) Wash pistons in P-D-680 solvent and re-
scrape carbon or sludge, do so lightly, with something
move all accumulated oil or carbon. Pay particular atten-
soft, like a square edge piece of hardwood. This will pre-
tion to the ring grooves. Be sure that oil return holes in the
vent marring of valve or seating surface.
oil control wiper ring grooves are open, and that grooves
(9) Clean thoroughly, then inspect bearings for
themselves are absolutely clean.
signs of wear, or roughness. If bearings are worn, rough,
(4) Inspect the cylinder bore for any signs of
or have other damage, replace the crankshaft assembly.
scoring or scuffing. If the cylinder bore shows signs of
(10) Clean the unloader parts (fig. 4-3) thor-
wear or scoring, as indicated by visible ridging at the end
oughly, then inspect weights and pins for a free fit.
of ring travel, it must be replaced (see (6) below).
(5) Inspect the piston for signs of scoring, or
(crankcase) on workbench. Fasten it down so it will not tip
for any indication of cracked or broken lands. If these
over when weight is added by assembly.
signs are found, replace the piston. If piston shows no
signs of scoring, or cracked or broken lands, check the
NOTE
condition of ring grooves for signs of excessive wear. A
Install new gaskets in all positions at reassem-
tapered ring groove would result in excessive clearance,
bly, and a new oil seal in the shaft end cover.
and that piston should be replaced.
(1) Slide the crankshaft (3, fig. 6-8) through the
NOTE
end cover opening until bearings seat in compressor
frame.
If new ring sets are to be installed on pistons,
(2) Tap journal end of shaft with a soft faced
and the old cylinder is going to be reused, the
hammer until the retaining ring groove extends approxi-
cylinder walls must be deglazed, or slightly
mately 1/6 inch (0.04 cm) out of housing.
roughened to provide a proper seating-in sur-
(3) Insert retaining ring in its groove, then tap
face for the new piston rings.
the keyway end of the shaft with a soft faced hammer,
(6) Cylinders that passed inspection in (4)
until the retaining ring is tight against the housing.
above, and are to be reused, must be deglazed as fol-
lows:
CAUTION
WARNING
Install oil seal with the sealing lip facing i n-
Dry cleaning solvent, P-D-680, used to clean
side of the shaft end cover, then press into
parts is potentially dangerous to personnel
position. If a vise is used to press the seal,
and property. Do not use near open flame or
be sure serrated jaws, if any, are covered to
excessive heat. Flash point of solvent is
protect seal from distortion.
100 (38 ) - 138 (59 ).
F
C
F
C
(4) Install the shaft end oil seal (16) (see Cau-
tion above) in housing (14).
(a) Use a No. 80 grit abrasive cloth
dampened in oleum spirits, or solvent Fed. Spec. P-D-
CAUTION
680, and move it over the surface of the bore in a rotating
Protect lip of the seal from cutting by the
and reciprocating motion with a very light pressure.
threads on end of crankshaft by wrapping a
(b) After deglazing, the cylinder wall
sheet of 0.003 inch brass shim stock around
should be thoroughly cleaned with a hot soapy solution,
threads, then slipping shaft end cover and
using a good stiff bristle (not wire) brush. Rinse thoroughly
seal in position on frame.
with hot water then check cleanliness of the bore by wip-
(5) Place gasket (15) in position around shaft, then
ing with a soft white paper cloth. If the paper shows more
6-12
