package assembly
to be determined quickly and
b. Open drain cock and drain oil from compressor
efficiently. Failure of
a compressor package assembly to
oil reservoir. Close (.rain cock.
perform as specified
indicates the need for adjustments
NOTE
and/or the repair
or replacement of component
Refer to paragraphs 3.4.2 and 3.4.3
assemblies.
for types of lubricating oil, and
3.6.2 Before starting the tests, perform the pre-operating
paragraph 3.4.4 for changing types
inspections and servicing procedures as specified in
of oil.
paragraphs 2.2 and 2.3. Close the system drain valve and
c. Pour approximately five pints of lubricating oil, of
both shutoff valves located on the instrument panel; open
same type previously used, into compressor crankcase
the receiver shutoff valve. Start the engine in accordance
through breather body assembly. Check level of oil in
with the instructions in paragraph 2.6 and allow an
reservoir by observing indicator sight mounted on side of
approximate 5 minute warm-up period.
reservoir. Add oil as necessary to bring level up to full
mark on indicator sight.
3.6.3 LEAKAGE TEST. With the engine operating at full
throttle and air pressure in the receiver increasing, brush a
d. Wash breather cover and filter assembly in dry-
soap-water solution on all pneumatic system connection
cleaning solvent (Federal Specification P-S-661).
points and the joints of the component assemblies. Check
Replace breather cover and filter assembly on breather
for air leakage as indicated by bubbles. There shall be no
body assembly.
visible indications of air leakage through the complete
3.4.2 The air compressor assembly is designed to
operating pressure range of 0 to 3300 psig. Eliminate all
operate with two types of lubricating oil.
When
pressure leaks by tightening coupling nuts, fittings,
compressing breathing quality air, use only special
connections, and/or replacing defective gaskets, packings
medicinal grade, mineral base lubricating oil (Stewart
or component assemblies.
Warner part number 130A1190). For other applications,
3.6.4 PRESSURE REGULATOR AND GAGE TEST.
including operation at temperatures below 32 F (0 ),
C
Connect the air hose and chuck assembly to the low
use only aircraft instrument lubricating oil (Specification
pressure outlet fitting on the instrument panel Open the
MIL-L-6085A). DO NOT INTERMIX THE TWO TYPES
pressure servicing valve on the air hose just enough to
OF OIL.
allow a slight air flow, then open the low pressure shutoff
3.4.3 The two types of oil are easily distinguished by
valve. Adjust the low pressure regulator to obtain outlet
their color.
Special medicinal grade, mineral base
pressures from 0 to 200 psi as indicated by the low
lubricating oil is a clear, colorless liquid.
Aircraft
pressure gage. Close the low pressure shutoff valve,
instrument lubricating oil (Specification MIL-L-6085A) has
connect the air hose and chuck assembly to the high-
an amber color. Both oils will tend to cloud after use but
pressure outlet fitting, and repeat the tests over the high
can still be recognized by their color.
pressure range (0 to 3300 psig). No erratic pressure gage
indications, excessive pressure creepage, or evidence of
3.44
The following procedure should be observed
pneumatic or mechanical malfunctions are permissible.
carefully when changing from aircraft instrument
lubricating oil (Specification MIL-L-6085A) to special
3.6.5
PUSH VALVE TEST.
With the compressor
medicinal grade, mineral base lubricating oil.
The
operating and air pressure in the receiver at approximately
procedure need not be followed when changing from
3000 psig, depress the push valve on the instrument panel
medicinal grade oil to aircraft instrument oil.
for approximately 5 seconds.
The condensate
accumulated in the filter and separator assembly should
a. Drain oil reservoir and refill with medicinal grade
blow down with a pronounced sound. Release the push
oil, and wash breather cover and filter assembly. (Refer
valve.
The pneumatic dump valve should close,
preventing the further escape of air from the blow down
b. Operate compressor
package
assembly
for
tube.
approximately 15 minutes.
3.6.6 BLOW DOWN ON SHUT DOWN. With the
c. Press push valve and allow condensate to blow
compressor operating and both pressure shutoff valves on
to atmosphere. Stop compressor package assembly.
the instrument panel closed, move the engine throttle to
the idle position. Press the engine stop button. The
d. Drain oil reservoir and refill with medicinal grade
condensate accumulated in the filter and separator
oil. Compressor package assembly can now be used for
assembly should blow down within 90 seconds after the
compressing breathing quality air.
engine stops.
3.5. Refer to the lubrication order (figure 3-1) for engine
lubrication instructions.
3.6.7 SYSTEM DRAIN. With the unit inoperative, open
the system drain valve to relieve air pressure to
3.6 FUNCTIONAL TESTS
atmosphere. Open both shutoff valves on the instrument
panel.
3.6.1 The following functional tests enable the operating
capabilities of a new, repaired or overhauled compressor
23
