AIR TRACTOR AT-502A, Maintenance Section

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Air Tractor, Inc. Maintenance Page 41
AT-502A/502B/504 March 14, 2018
C. Oil Amount (Compressor swap, no flushing)
•
The goal of this procedure is to measure the oil amount
in the failed compressor and adjust the amount in the
new compressor to equal that of the failed
a) Remove the oil plug from the failed compressor and drain
as much oil as possible into a suitable container.
b) Drain oil from the suction and discharge ports into a
suitable container while turning the shaft clockwise only
with a socket wrench on the armature retaining nut.
c) Measure and record the amount of oil drained from the
compressor.
d) Drain oil from the new compressor following steps a) and
b).
e) Add oil back into the new compressor in an amount equal
measurement taken in step c).
f) Re-install oil plug. Seal and O-ring must be clean and not
damaged. Torque to 11-
15 ft•lb (15-20 N•m, 150-200
kgf•cm). Be careful not to cross thread the oil plug.
7. Service Procedures
A. Flushing
a) Equipment types
•
Refrigerant recovery recycle machines which contain a flushing circulating pump to
solvent- clean using R134a.
•
A closed loop flushing machine in which the circulated flushing fluid is returned to a
reservoir for filtering and continued circulation. Most of these machines provide a pulsing
action to dislodge particles that are stuck in small passageways.
•
A pressurized flush gun with a pulsating spray can also be used. To use this technique,
block one end of a air conditioning system component being flushed in order to build
pressure inside the component, and then quickly release the blockage to pulse the
flushing solvent out.
b) Safety
•
Do not use flammable fluids.
•
Protect eyes with safety goggles.
•
Wear chemical resistant gloves.
•
Use approved fluids. CFCs R-11,113 or 115 and Methyl Chloroform also known as 1,1,1,
Trichloroethane are not acceptable per the Clean Air Act.
c) Acceptable Flushing Fluids
•
Fluids designated for air conditioning flushing should be used and may be either solvent
or lubricant based. Fluids used to flush the system should meet SAE specification J2670
to insure compatibility with refrigerant, oil and any materials used in the air conditioning
system.