SECTION III
PREVENTIVE MAINTENANCE
c. Slip used dehydrator cartridge (14) out of
3.1 GENERAL
dehydrator housing.
3.1.1 This Section contains instructions for performing the
d. Remove desiccant indicator assembly from
periodic servicing and preventive maintenance necessary
each end of replacement dehydrator cartridge.
to assure the continued efficient operation of the
compressor package assembly and to minimize the
NOTE
possibility of inadvertent break-down of the equipment.
Desiccant indicator assemblies
Included are the recommended procedures and intervals
are installed on all replacement
for cleaning, inspecting, lubricating and testing the overall
dehydrator cartridges to provide
equipment. Where necessary, references are made to
an air-tight seal that prevents
other sections of this service manual for more detailed
exposure of desiccant in cartridge
instructions and/or additional information.
to moisture during shipment and
storage.
Examine desiccant
3.2 CLEANING
indicators after removal. Do not
3.2.1 EXTERNAL SURFACES. Keep the external
use
dehydrator
cartridge
if
surfaces of the compressor package assembly clean at all
indicator desiccant is not blue in
times. Use clean, lint-free cloths dampened with dry-
color.
cleaning solvent (Federal Specification P-S-661) to
e. Make certain preformed packing and lock ring
remove all dust, dirt, oil, grease, and gummy substances
are installed in grooves at outlet end of dehydrator
from all component assemblies. Dry the surface with
cartridge (14). Install cartridge in dehydrator housing in
clean cloths and/or low-pressure compressed air. Be
accordance with instructions on cartridge body.
especially careful to remove all caked deposits from
between the cooling fins of the compressor aftercooler,
f. Screw adapter cap (4), together with filter disc
interstage connecting tubes and cylinders, and the cooling
(7), packing back-up ring (6) and quad ring packing (5),
fins of the engine cylinder.
on dehydrator housing finger-tight, then use appropriate
wrench to tighten cap with a torque of 10 pound feet.
3.2.2 COMPRESSOR AIR INTAKE FILTER. At least
once every 50 hours of accrued compressor operating
g. Use 0.032 inch diameter Monel wire to safety
time, or at shorter intervals if climatic conditions are
wire adapter cap to housing as in original installation.
excessively dry and dusty, remove the silencer cover and
3.2.4 LINE FILTER. At least once every 100 hours of
intake filter (see Figure 5-12) from the compressor first
accrued compressor operating time, or at shorter
stage cylinder head. Thoroughly clean the intake filter by
intervals if climatic conditions are excessively dry and
washing in ethyl alcohol (Federal Specification O-A-396)
dusty, .Remove the filter element from the line filter
and allow to air dry. Discard the intake filter if it is
(see Figure 1-4). Inspect the filter element carefully for
damaged or cannot be completely cleaned. Use a clean
cleanliness, damage and indications of deterioration. If
cloth moistened with dry-cleaning solvent to wipe the
the filter element is in good physical condition, wash it
inside of the silencer cover and the cylinder head, then
thoroughly in ethyl alcohol (Federal Specification O-A-
remove all traces of residue with a clean, dry, lint-free
396) and allow to air dry. Re-install the cleaned
cloth. Replace the intake filter and the silencer cover on
element, or a replacement element if required, in the
the first stage cylinder head.
line filter. Be sure the original equipment configuration
3.2.3 DEHYDRATOR CARTRIDGE. At least once every
is restored and the filter cap is properly safety wired.
50 hours of accrued compressor operating time, or at
shorter intervals if climatic conditions are excessively
CAUTION
humid, replace the dehydrator cartridge as follows:
Be sure receiver shutoff valve is
a. With compressor inoperative, close receiver
closed and system drain valve
shutoff valve (see Figure 1-4) and open system drain
open before attempting to remove
valve (see Figure 1-3).
the line filter element.
b. (See Figure 5-10.) Cut safety wire and remove
3.2.5 COMPRESSOR STRAINER AND RELIEF
outlet adapter cap (4) of dehydrator housing (13). Be
VALVE ASSEMBLY. At least once every 200 hours of
careful not to damage quad ring packing (5), packing
accrued compressor operating time, remove the strainer
back-up ring (6) and filter disc (7) which are removed with
from the strainer and relief valve assembly mounted on
cap.
the compressor second stage cylinder
NOTE:
This also applies to the third stage strainer and
relief valve used on Model 19 380219.
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