compressed air. Be sure all drilled passages are clean
b. Slowly increase air pressure applied to strainer
and unobstructed. Inspect parts for scoring, scratches,
and relief valve assembly until valve opens, allowing air to
corrosion, wear and other signs of damage. Refer to
escape to atmosphere through holes drilled in adjusting
plug.
questionable parts, and install new items during
c. Place a collector cup over seat housing end of
reassembly.
assembly. Connect a 1/4-inch inner diameter hose to
4.14.7.3
REASSEMBLY. Reassemble the oil pump,
collector cup and immerse opposite end of hose about one
sight indicator and oil reservoir by performing the removal
inch in a container of water.
procedure in reverse sequence. Be sure all gaskets are in
d. Shut off air pressure applied to strainer and relief
good condition and properly installed, and that all screws
valve assembly. As applied pressure decreases, observe
and nuts are tightened sufficiently to eliminate oil leaks.
pressure gage and note pressure at which valve closes
Install safety wire as in the original equipment
(i.e., leakage rate as indicated by escaping air bubbles is
configuration.
one bubble per second or less).
4.14.8
INSTALLING
AIR
COMPRESSOR
(See
e. Second stage strainer and relief valve should
Figure 5-11.
close before applied pressure drops below 100 PSIG.
a. Align air compressor (3) with shaft of gasoline
Third stage strainer and valve should close before applied
engine (20) and carefully mate units. Engage draw bolt
pressure drops below 700 PSIG.
(11, Figure 5-12) with tapped hole in engine crankshaft but
f. If necessary, readjust sprig adjusting plug to
do not tighten. Install cap screws (4) and lock washers (5)
obtain required operation of strainer and relief valve
attaching compressor to engine, but do not tighten.
assembly. Turn plug clockwise to increase pressure,
b. Slip spacers (6) between mating surfaces of
counterclockwise to lower closing pressure.
compressor and engine. Tighten cap screws (4) as
g. Repeat alternate tests and adjustments until
necessary to hold spacers in place. Tighten draw bolt with
strainer and relief valve functions as specified. Safety
a torque of 125 to 150 pound-inches, then loosen cap
wire adjusting plug to seat housing with 0.025 inch
screws and remove spacers. Retighten cap screws.
diameter stainless steel wire.
c. Attach nameplate (4, Figure 5-12) to compressor
4.14.6.6 INSTALLATION. Refer to paragraph 4.14.4.3,
fan guard with screws and lock washers (5 and 6, Figure
step f.
4.14.7 OIL
PUMP,
SIGHT
INDICATOR
AND
d. Reconnect aftercooler-to-separator connecting
RESERVOIR
tube (22, Figure 5-3) to union installed in compressor
aftercooler.
4.1.7.1 REMOVAL (See Figure 5-12).
e. Reconnect first-stage-to-filter connecting tube (17,
a. Make certain all lubricating oil is drained from
crankcase. Remove drain cock and elbows (1 and 2,
cylinder head.
f. Replace housing on compressor end of cart (refer
b. Remove eight screws and lift sight glass cup (35),
gaskets (38 and 39) and sight indicator(37)from side of oil
reservoir (46).
4.14.9
COMPRESSOR
PRELIMINARY
LUBRICATION RUN
c. Remove four screws (41) and carefully slip oil
pump housing (40) and gasket (42) from bottom of oil
4.14.9.1
During normal compressor operation, the
reservoir (46).
small quantity of oil vapor that passes from the first stage
d. Remove two screws (44) and pull oil pump
cylinder to the second and third stage cylinders along with
cylinder (43) and packing (45) from oil pump housing (45).
the compressed air provides the necessary piston to
cylinder lubrication. However, following overhaul of the
e. Remove fasteners (47) and pull oil reservoir (46)
air compressor assembly or replacement of any part of the
from compressor crankcase (117). Remove and discard
assembly, the compressor must operate for an
oil reservoir gasket (48).
appreciable time before the lubricant is thoroughly
circulated in this manner. To prevent damage to the
f. Cut safety wire and unscrew oil pump piston
second and third stage cylinder and piston assemblies
retainer (50) from master rod (113). Remove shims (51),
during this initial period of operation, all repaired and/or
oil pump piston (49), ball retainer (53) and master rod
overhauled air compressor assemblies first must be
socket (54).
operated in accordance with the following instructions:
4.14.7.2
CLEANING AND INSPECTION. Clean all
a. Disconnect first-to-second-stage connecting tube
parts by washing In dry -cleaning solvent (Federal
at second stage strainer and relief valve assembly.
Specification PS-661). Dry parts with clean, lint-free
cloths and/or
40
