case. The crankcase is a single casting comprising the
1st stage cylinder, the 2d stage cylinder, the oil sump as
well as the, housing for the rotating parts. Located in
the oil sump portion of the crankcase are the drain plug,
rod-cap and tube assembly. The tube assembly serves
to siphon and filter the oil from the oil sump to the gerotor
which pumps the oil to the other portions of the
compressor group. The rod-cap is located at the top of
the oil sump and is used to determine the oil level within
the oil sump. The drain plug is located at the bottom of
the oil sump and is used to drain the oil sump and to
provide an access to the tube assembly.
14. Maintenance
Third echelon maintenance personnel are authorized to
replace the drain plug, preformed packing, rod-cap,
spring tension washer, tube assembly and any attaching
hardware.
a. Removal. Removal of the compressor group is
not required for replacement of components at the third
echelon.
b. Disassembly (fig. 4)
(1) Unscrew the drain plug (7) from the
crankcase and remove the preformed
packing (6).
(2) Rotate the rod-cap (1) and remove it from
the crankcase.
Remove the preformed
packing (2).
(3) Disassemble the two screws (3) and remove
the spring tension washer (4) from the
crankcase.
(4) Unscrew the tube assembly (5), using a
suitable size screwdriver, and remove it from
the interior of the oil sump of the crankcase
c. Cleaning and Inspection (fig. 4).
(1) Clean all metallic parts with dry-cleaning
solvent.
(2) Blow out the tube assembly (5) through both
orifices using compressed air.
(3) Inspect all parts for distortion, cracks,
defective threads or other damage. Replace
if defective.
(4) Replace the preformed packings (2 and 6)
1
Water separator
4
Nut
and the spring tension washer (4).
2
Clamp
5
Needle valve
3
Washer
6
Fitting
Figure 2. Water separator group, exploded view.
addition to the three pressure stages, the compressor
group includes a crankcase section The crankcase
section consists of the crankshaft, keystone, gerotor,
bearings, and a crank-
AGO 648A
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