TM 55-4920-384-13&P
(d) Open the flow control valve.
leaks and correct as necessary. Stop the unit, wait 5
(e) Remove the reservoir fill cap. Remove
minutes, and check the oil level. Add oil to bring the
the coupling half from the opposite end of the at-
oil level up to the FULL mark if necessary.
tached 1/2 inch hose assembly and insert the open
end into the reservoir being careful not to damage
(2) Oil Filter.
the screen in the filler neck of the reservoir.
(a) Loosen the bolt and remove the cover
(f) Set the fluid volume control at 2 GPM
from the oil filter.
as registered on the fluid flow indicator.
(b) Remove the cartridge from inside the
(g) Start the test stand and circulate hy-
filter and discard.
draulic fluid through the system and back into the
(c) Wipe the inside of the filter with a lint
reservoir until all traces of air bubbles are gone
free cloth making sure all dirt and sludge are re-
from the fluid flowing into the reservoir.
moved.
(h) Stop the test stand and disconnect the
(d) Insert a new cartridge in the filter
hose assembly. Cap both ends of the hose assembly
body. Be sure the correct end of the cartridge is up.
and the coupling half on the test stand.
(e) Install a new gasket in the cover. Place
d. Hydraulic Filter Element Replacement -
the cover on the oil filter and tighten the bolt.
LOW Pressure. The high pressure filter and the
(f) Add one quart of oil to the engine crank-
low pressure filter are protected with differential
case to compensate for oil lost in servicing the oil
pressure switches which, when the pressure drop
filter. Refer to lubrication chart Table 1-2 for the
,
across the filter reaches a valve at which change of
proper grade of oil.
the filter element is required, illuminates a red
(g) Operate the unit immediately after ser-
warning light on the control panel.
vicing and check for oil leaks.
b. Air Cleaner.
CAUTION
(1) Remove the air intake cap.
After every replacement of the
(2) Loosen the thumbscrew and remove the oil
low pressure filter element, the
cup from the air cleaner assembly.
hydraulic system must be bled
(3) Discard the oil cup. Wash the oil cup and
air intake in an approved P-D-680 cleaning solvent
of air.
and dry thoroughly.
(4) Fill the oil cup to the level mark with
(1) Remove housing cover from stand per
clean oil of the proper grade. Refer to instructions
on side of cup per paragraph 2-2a (4). Install the oil
(2) Place selector valve in RETURN position.
cup on the air cleaner body and tighten the thumb-
(3) Drain approximately one quart of oil fluid
screw to secure.
from filter housing.
(5) Install the air intake cap on the top of the
(4) Remove 1/4 - 20 screws from top of low
air cleaner assembly.
pressure filter housing - remove cover.
c. Hydraulic System. The hydraulic system of
(5) Remove old element from housing. Install
the test stand must, at all times, be free of leaks.
new element.
The efficiency of the test stand will be impaired if a
(6) Replace cover on filter housing.
leak exists anywhere in the system.
(1) Component Removal. In the event that
e. Hydraulic Filter Element Replacement -
a component in the hydraulic system is removed, all
High Pressure.
openings must be capped or plugged to prevent en-
(1) Open fuel tank access door on side of
trance of foreign matter to the system.
stand.
(2) Bleeding Air From the Hydraulic Sys-
(2) Place drain pan under high pressure filter
tem.
housing.
(a) Fill the reservoir with MIL-H-5606 flu-
(3) Remove lower part of filter housing with a
id.
strap or filter wrench.
(b) Open by-pass valve and allow air to es-
(4) Pull old element down from housing until
cape from the pressure filter. Close bleed valve
it unsnaps.
when air bubbles no longer appear close by-pass
(5) Insert new element into housing with open
valve. Place selector valve in RESERVOIR position.
end up. Press upward on element until it snaps into
position and supports itself.
(c) Connect the 1/2 inch hose assembly to
(6) Replace lower part of filter housing with a
the coupling half.
strap or filter wrench.
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