TM 5-3810-306-20
NOTE
Rear outriggers may be used to raise
crane in order to lower boom nose
slightly below horizontal.
a. If air in telescope cylinder is not readily removed,
lower
boom
to
below
horizontal,
extend
telescope cylinder as far as practicable, and
allow boom to remain in this position overnight.
WARNING
Extreme care must be used when
removing any plugs or restrictions
from a hydraulic system suspected to
have entrapped air that may be
pressurized.
NOTE
This should allow entrapped air to
find its way to holding valve so
telescoping boom IN next morning
should force air back to reservoir.
NOTE
While allowing boom to remain in
extended
and
lowered
position
overnight is helpful in removing
entrapped air from hydraulic cylinder,
ensure boom is first telescoped IN
(not OUT) in morning. Telescoping
OUT can cause air to be forced back
into cylinder.
b. Entrapped air can be removed from any cylinder
by cycling cylinder. On certain cylinders, a
plugged port is provided on rod end to bleed-off
entrapped air.
WARNING
Do not attempt to loosen fittings in
pressurized lines or while hydraulic
pumps are in operation.
c. If pumps and motors are noisy after bleeding
cylinders, bleed air by loosening various fittings.
END OF TASK
16-53
