TM-9-2350-256-10

RECOVERY VEHICLE, FULL TRACKED: MEDIUM, M88A1

OPERATOR'S MANUAL

OCTOBER 2014
TM-9-2350-256-10

  TM-9-2350-256-10 - Page 428 of 796

LOWERING BOOM
WARNING
Do not stand on top of vehicle while boom is being raised or lowered. Boom can fall or
cables can throw you off. Failure to comply may result in personnel death or injury.
CAUTION
•
If powerpack is removed and Auxiliary Power Unit (APU) is nonoperational, leave
boom in full raised position. Do not attempt to lower boom. Failure to comply may
result in damage to boom, boom cylinders, and hydraulic system.
•
To avoid damage to the boom and hydraulic system, always keep boom in stowed
position when not in use. Failure to comply may result in damage to equipment.
NOTE
In extreme or emergency cases, notify maintenance to ground hop APU and lower boom.
1.
Operate hoist winch (WP 0079) to raise the 25-ton (22.7-metric ton) snatch block. It will lay in the boom tray
when boom is lowered.
WARNING
Do not keep boom in full raised position for an extended period of time. Failure of the
hydraulic system could occur, allowing the boom to freefall when lowered, causing
personnel death or injury.
2.
Perform the following steps before lowering boom if boom has been in raised position for an extended
period of time.
a.
Move BOOM operating lever (Figure 5, Item 1) to FORWARD position, and hold for approximately
5 minutes. This allows system to fill with oil and eliminate any air pockets.
b.
Use BOOM operating lever (Figure 5, Item 1) to move boom backward and forward several times in
live boom area. This will assure that all air pockets have been eliminated and that boom will
operate smoothly.
3.
Move BOOM SAFETY control lever (Figure 5, Item 2) to STOW position and hold.
4.
Move BOOM operating lever (Figure 5, Item 1) to RETRACT position and hold.
5.
Continue to lower boom until it is about 1 ft (0.31 m) from the engine deck, then release BOOM operating
lever (Figure 5, Item 1). Release BOOM SAFETY operating lever (Figure 5, Item 2).
6.
Verify that stayline and hoist winch cables are safely stowed.
7.
Continue lowering boom, using both levers (Figure 5, Items 1 and 2) as required, until boom is in full-down
position against travel lock. Then release BOOM SAFETY operating lever (Figure 5, Item 2).
TM 9-2350-256-10
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