JLG 340AJ Service Manual - Manual (Page 156)

SECTION 4 - BOOM & PLATFORM
4-24 – JLG Lift – 3121259
Installation and Bleeding
After installation of the actuator on the equipment, it is impor-
tant that all safety devices such as tie rods or safety cables are
properly reattached.
To purge air from the hydraulic lines, connect them together
to create a closed loop and pump hydraulic fluid through
them. Review the hydraulic schematic to determine which
hydraulic lines to connect. The linear feet and inside diameter
of the hydraulic supply lines together with pump capacity will
determine the amount of pumping time required to fully
purge the hydraulic system.
Bleeding may be necessary if excessive backlash is exhibited
after the actuator is connected to the hydraulic system. The
following steps are recommended when a minimum of two
gallons (8 liters) is purged.
1. Connect a 3/16" inside diameter x 5/16" outside diame-
ter x 5 foot clear, vinyl drain tube to each of the two
bleed nipples. Secure them with hose clamps. Place the
vinyl tubes in a clean 5-gallon container to collect the
purged oil. The oil can be returned to the reservoir after
this procedure is completed.
2. With an operator in the platform, open both bleed nip-
ples 1/4 turn. Hydraulically rotate the platform to the
end of rotation (either clockwise or counterclockwise),
and maintain hydraulic pressure. Oil with small air bub-
bles will be seen flowing through the tubes. Allow a 1/2
gallon of fluid to be purged from the actuator.
3. Keep the fittings open and rotate the platform in the
opposite direction to the end position. Maintain hydrau-
lic pressure until an additional 1/4 gallon of fluid is
pumped into the container.
4. Repeat steps 2 & 3. After the last 1/2 gallon is purged,
close both bleed nipples before rotating away from the
end position.
TYPICAL CONFIGURATION OF ACTUA-
TOR