JLG 150HAX ANSI Service Manual - Manual (Page 106)

SECTION 5 - HYDRAULICS
5-10 – JLG Lift – 3120679
10. Place new o-rings and seals in the applicable out-
side diameter grooves of both the piston and the cyl-
inder head.
11. Position the cylinder barrel in a suitable holding fix-
ture.
EXTREME CARE SHOULD BE TAKEN WHEN INSTALLING THE CYL-
INDER ROD, HEAD, AND PISTON. AVOID PULLING THE ROD OFF-
CENTER, WHICH COULD CAUSE DAMAGE TO THE PISTON AND
CYLINDER BARREL SURFACES.
12. With barrel clamped securely, and while adequately
supporting the rod, insert the piston end into the
barrel cylinder. Ensure that the piston loading o-ring
and seal ring are not damaged or dislodged.
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.
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) through (20) apply to the telescope cylin-
der.
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) through (20) is to posi-
tion the barrel horizontally in a suitable holding
device, attach a hydraulic power source to both
extend and retract ports, while supporting the cylin-
der rod, cycle the cylinder a minimum of 5 times with
the bleeder port unplugged, venting all trapped air
to atmosphere. 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.
Table 5-2.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)