JLG 110HX Service Manual - Manual (Page 46)

SECTION 2 - PROCEDURES
2-22 – JLG Lift – 3120864
Assembly
NOTE: Prior to cylinder assembly, ensure that the proper
cylinder seal kit is used. See your JLG Parts Manual.
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Apply a light film of hydraulic oil to all components
prior to assembly.
WHEN INSTALLING NEW “POLY-PAK” TYPE PISTON SEALS,
ENSURE SEALS ARE INSTALLED PROPERLY. REFER TO FIGURE
2-8 FOR CORRECT SEAL ORIENTATION. IMPROPER SEAL
INSTALLATION COULD RESULT IN CYLINDER LEAKAGE AND
IMPROPER CYLINDER OPERATION.
1. Place a new wiper seal and rod seal into the applica-
ble cylinder head gland grooves.
2. Carefully install the head gland on the rod, ensuring
that the wiper and rod seals are not damaged or dis-
lodged. Push the head along the rod to the rod end,
as applicable.
3. Carefully slide the piston spacer on the rod. If appli-
cable, align the oil holes in the rod and the spacer.
Secure the spacer, if applicable.
4. If applicable, correctly place a new o-ring and back-
up rings in the inner piston diameter groove.
5. Carefully place the piston on the cylinder rod, ensur-
ing that the o-ring and back-up rings are not dam-
aged or dislodged.
6. Using suitable protection, clamp the cylinder rod in
a vise or similar holding fixture as close to the piston
as possible.
7. Push the piston onto the rod until it abuts the spacer
end and install the attaching nut.
IF CYLINDER IS EQUIPPED WITH A PISTON NUT, APPLY “LOC-
QUIC PRIMER T” AND LOCTITE #242 TO PISTON NUT THREADS,
THEN TIGHTEN NUT TO TORQUE SHOWN IN TABLE 2-2.
NOTE: Self-locking setscrews used on piston nuts should be
discarded and replaced whenever they are removed.
8. If applicable, torque the piston nut to the proper
torque as outlined in Table 2-2. Spot drill the piston
rod at the point where the setscrew is inserted into
the piston nut. Install the setscrew(s) which secure
the piston attaching nut to the diameter groove.
9. Remove the cylinder rod from the holding fixture.
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
CYLINDER 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.
Figure 2-8. Poly-Pak Seal Installation
Table 2-2.Cylinder Piston Nut Torque Specifications.
Description
Nut
Torque Value
(Wet)
Setscrew
Torque Value
(Dry)
Lift Cylinder 814 Nm 22.5 Nm
Slave Cylinder 109 Nm 12 Nm
Master Cylinder 109 Nm 12 Nm
Steer Cylinder 109 Nm 12 Nm
Telescope Cylinder 814 Nm 12 Nm
Axle Extension Cylinder 109 Nm 12 Nm
Axle Lift Cylinder 553 Nm 12 Nm
Extend - A - Reach
Lift Cylinder 553 Nm 12 Nm
Slave Cylinder 271 Nm 12 Nm