TM 5-3805-290-23-2
PILOT OIL ACCUMULATOR MAINTENANCE - CONTINUED
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TESTING AND CHARGING
N OT E
The following procedure can be used to test the pilot accumulator. Pilot accumulator maintains pressure in
pilot hydraulic system. Accumulator allows boom to be lowered and tools to work with stopped engine.
When testing or charging pilot accumulator, pressure in pilot hydraulic system must be released. Tempera-
ture of nitrogen gas must also be taken into account. Pressure and volume of nitrogen gas varies with temper-
ature.
Operational Test for Pilot Oil Accumulator
1.
Remove right chassis covers (WP 0107 00) for access to pressure reducing valve.
2.
Turn engine start switch to ON position (TM 5-3805-290-10). Move joystick, third function lever, and fourth function
control through full range of travel. Repeat moving levers several times.
N OT E
Operating joystick and levers will release pressure in pressure reducing valve.
3.
Connect Test stand, automotive (gage set) (Item 92,
WP 0205 00) to Hose (Item 38, WP 0205 00) with
quick-disconnect fittings.
4.
Connect other end of Hose (Item 38, WP 0205 00) to
pressure tap (6) for pilot pressure on pressure reducing
valve (7).
427-B0783
5.
Start engine (TM 5-3805-290-10) and run at HIGH idle. Pressure gage will read 450 25 psi (310 172 kPa).
6.
Shut down engine.
7.
Turn engine start switch to ON position (TM 5-3805-290-10).
8.
Move joystick to release pressure in pressure reducing valve.
9.
Observe pressure gage as joystick is moved. Pressure will steadily decrease.
10.
When pressure reaches approximately 125 psi (860 kPa), pressure will suddenly drop to zero. This occurs because no oil
is left in accumulator (2). Final pressure, prior to sudden drop to zero, is approximate pressure of accumulator charge.
Discharging Accumulator
1.
With oil in hydraulic system at normal operating temperature, park machine on smooth, level surface (TM 5-3805-290-
10).
2.
Install steering frame lock (TM 5-3805-290-10).
3.
Turn engine start switch to ON position (TM 5-3805-290-10).
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