JLG 110HX ANSI Service Manual - Manual (Page 47)

SECTION 2 - PROCEDURES
3120636 – JLG Lift – 2-23
13. Continue pushing the rod into the barrel until the cyl-
inder head gland can be inserted into the barrel cyl-
inder or, if applicable, until the cylinder head threads
engage the threads of the barrel.
14. If applicable, secure the cylinder head retainer using
a suitable spanner type wrench in the holes pro-
vided.
15. After the cylinder has been reassembled, the rod
should be pushed all the way in (fully retracted) prior
to the reinstallation of any holding valve or valves.
16. If applicable, install the cartridge-type holding valve
and fittings in the rod port block using new o-rings
as applicable. Torque holding valves in accordance
with Table 2-3, Holding Valve Torque Specifications.
IF THE CYLINDER IS TO BE TESTED PRIOR TO INSTALLATION ON
THE MACHINE, EXTREME CARE SHOULD BE USED TO INSURE
THAT THE OUTER END OF THE ROD IS SUPPORTED. USE
EITHER A TRAVELING OVERHEAD HOIST, FORKLIFT, OR OTHER
MEANS TO SUPPORT THE OVERHANGING WEIGHT OF THE
EXTENDING ROD.
NOTE: Steps (17) thru (20) apply to the telescope cylinder.
17. Elevate the barrel end of the cylinder to a work
bench or other suitable device.
18. Plug the retract port and supply hydraulic power to
the extend port.
19. Open the bleeder port plug (TP), venting all trapped
air to atmosphere. Retighten the bleeder port plug.
Disconnect the hydraulic power source and remove
plug from retract port.
20. An alternative to steps (18) thru (20) is to position
the barrel horizontally in a suitable holding device,
attach a hydraulic power source to both extend and
retract ports, while supporting the cylinder rod, cycle
the cylinder a minimum of 5 times with the bleeder
port unplugged, venting all trapped air to atmo-
sphere. A suitable hose may be attached to the
bleeder port with the end in a container suitable to
contain the hydraulic fluid. After all air is vented
remove all attached hoses, and install the bleeder
port plug. Also plug the extend and retract ports until
cylinder is installed in boom.
2.12 BOOM MAINTENANCE
Removal
1. Shut down machine systems.
NOTE: Boom Assembly weighs approximately 10,000 (4536
kg).
2. Using suitable lifting equipment, adequately support
boom weight along entire length of retracted boom.
HYDRAULIC LINES AND PORTS SHOULD BE CAPPED IMMEDI-
ATELY AFTER DISCONNECTING LINES TO AVOID ENTRY OF
CONTAMINANTS INTO SYSTEM.
3. Tag and disconnect hydraulic lines that run along
the side of the boom.
4. Remove hardware attaching upper lift cylinder
attach pin to boom.
5. Using a slide hammer or similar tool, and taking care
not to damage pin, remove pin from boom.
6. Using all applicable safety precautions, and only if
necessary, operate crane and fully retract lift cylin-
der.
7. Shut down machine systems.
8. Tag and disconnect all wiring to ground control box.
9. Remove boom length/angle indicator box.
10. Loosen and remove hardware securing boom pivot
pin.
11. Ensuring that boom is adequately supported and
using a suitable slide hammer, carefully remove
pivot pin from boom and turntable structure. Ensure
that boom and turntable structure are not damaged.
12. Carefully lift boom assembly clear of turntable and
lower to ground or suitably supported work surface.
Table 2-3.Holding Valve Torque Specifications
Description Torque Value
Sun - 7/8 Hex M20 x 1.5 Thds. 30-35 ft. lbs.
(41-48 Nm)
Sun - 1 1/8 Hex 1/14 UND Thds. 45-50 ft. lbs.
(61-68 Nm)
Sun - 1 1/4 Hex M36 x 2 Thds. 150-160 ft. lbs.
(204-217 Nm)
Racine - 1 1/8 Hex 1 1/16 - 12 Thds. 50-55 ft. lbs.
(68-75 Nm)
Racine - 1 3/8 Hex 1 3/16 - 12 Thds. 75-80 ft. lbs.
(102-109 Nm)
Racine - 1 7/8 Hex 1 5/8 - 12 Thds. 100-110 ft. lbs.
(136-149 Nm)