TM 5-4930-218-14
6-4. Repair
c. Remove air nipple and screen (6), valve (7), and
nipple (8).
a. Repairs consist mainly of replacing all packings
d. You can unscrew and remove the oiler assembly
and parts which fail to pass inspection.
(9 through 17) and disassemble on bench. Remove the
b. You can remove minor nicks or scratches using a
filler cap (9) and packing (10). Unscrew the oiler head
fine stone, then polish with fine emery cloth or
(11) and remove the gasket (12), oil wick (13), wick
crocus cloth. Reclean parts after polishing,
tube (14), sight tube (15), and gasket (16) from the
c. Clean up any damaged threads using a fine file
oiler body (17).
or taps and dies of the correct size.
e. Unscrew the foot valve body (19) from the pump
tube (22) and remove retainer (20) and ball (21).
6-5. Reassembly
a. Reassembly is essentially the reverse of
NOTE
disassembly. Note the following:
To prevent marring surface finishes, use a suitable
(1) You should apply a light coating of engine oil
strap wrench to hold parts without wrenching flats or
on all packings, leather cup, and tubes with interior
parts that have polished surfaces. Use a soft-jawed vise
when clamping parts to disassemble.
or exterior sliding surfaces.
(2) Assemble air piston tube assembly (40
f. Unscrew and remove the pump tube (22) from the
through 53, fig. 6-1) on a bench. When completed,
pump inlet body (58).
check action of upper and lower valve plates and
g. After nut (23) and low pressure valve (24) are
valves. Valve plates should move freely with no bind-
removed, piston assembly (25, 26, and 27), spring (28),
ing of the lower valve plate on the air piston adapter
and washer (29) will slide off lower pump rod (32).
(51). If valve operation is satisfactory, lubricate the
h. Unscrew and remove the cylinder (30) from the
inside of tube and carefully install in pump body.
cylinder support (36).
(3) Assemble upper and lower pump rods (33 and
i. After cotter pin (31) is removed, unscrew assem-
32) to piston (35). Install packings (34) on piston and
bled upper pump rod (33), lower pump rod (32), and
lubricate liberally with engine oil. Install assembly,
upper piston (35) from adapter (52). Unscrew pump
upper pump rod first, through cylinder (30) and
rods from the piston, Unscrew the cylinder support
thread into adapter (52). Aline holes in upper pump
(36).
rod and adapter, then install cotter pin (31).
j. Remove cylinder cap (37), spring (38), and then
unscrew and remove air cylinder (39).
NOTE
To prevent damage to piston packing, use care when in-
k. Push air piston tube assembly (40 through 53)
serting the piston into the cylinder. The chamfer on the
out of pump body and disassemble. Use care when
inside edge of the cylinider should compress the packing
handling polished surfaces of air piston tube. To
and the piston should enter the cylinder easily.
remove upper valve plate (43) and exhaust valve stem
(4) Place flat side of leather cup (26) against flat
(44), remove nuts (40 and 42) and packing (41).
surface of piston nut (25), then thread lower piston
Remove nuts (45) to remove lower valve plate (50), in-
(27) on piston nut. Tighten parts sufficiently, but do
take valve stem (46), and packing (47) from air piston
not distort leather cup. Leather cup will flare out if
(49). Unscrew air piston from adapter (51). Unscrew
excessively tightened and rapid wear of the cup will
and remove air piston adapter (51) and piston rod
result.
adapter (52) from air piston tube.
(5) Assemble oiler and component parts (6
1. Remove spring (54) and packing (55) from inlet
through 18) on the bench, and install as an assembly
body (58).
in the pump body. Fill oiler assembly with recom-
mended lubricant.
b. After reassembly you should test the transfer
a. Discard and replace all packings.
pump for correct operation. Proceed as follows:
(1) Install transfer pump in a drum of lubricant.
b. Clean all remaining parts with dry cleaning
Connect transfer hose to pump.
solvent (fed. spec. P-D-680).
C. Check to see that foot valve is clean and free
(2) Make certain that shutoff valve, adjacent to
oiler, is closed.
from dirt and foreign matter. Inspect ball and seat in
(3) Connect an outside air supply of ap-
valve body for damage. Also check low pressure valve
proximately 150 psi to the transfer pump.
for damage to seat face.
d. Check to see that air valve is clean and operates
(4) Direct hose nozzle into a container, then
slowly open shutoff valve. Open valve sufficiently to
easily.
check pump operation.
e. Inspect pump rods and tubes for cracks, breaks,
or other defects which would prevent proper
(5) If pump functions correctly, shut off air at
the pump and disconnect air supply.
operation.
