JLG 150HAX Service Manual - Manual (Page 105)

SECTION 5 - HYDRAULICS
3120817 – JLG Lift – 5-9
14. Inspect travel limiting collar or spacer for burrs and
sharp edges. If necessary, dress inside diameter
surface with Scotch Brite or equivalent.
15. If applicable, inspect port block fittings and holding
valve. Replace as necessary.
16. Inspect the oil ports for blockage or the presence of
dirt or other foreign material. Repair as necessary.
17. If applicable, inspect piston rings for cracks or other
damage. Replace as necessary.
Assembly
NOTE: Prior to cylinder assembly, ensure that the proper
cylinder seal kit is used. See your JLG Parts Manual.
NOTE: 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
2-1 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 JLG THREADLOCKER P/N 0100011 TO PIS-
TON NUT THREADS, THEN TIGHTEN NUT TO TORQUE SHOWN IN
Table 5-1.
NOTE: Self-locking setscrews used on piston nuts should
be discarded and replaced whenever they are
removed.
8. If applicable, install the setscrew(s) which secure the
piston attaching nut to the diameter groove.
9. Remove the cylinder rod from the holding fixture.
Figure 5-1. Poly-Pak Seal Installation
Table 5-1. Cylinder Piston Nut Torque Specifications
Description
Piston Nut
Torque Value
(w/
Threadlocker)
Setscrew
Torque Value
(w/o
Threadlocker)
Main Lift Cylinder
600 ft. lb.
(Nm)
200 in. lb.
(23 Nm)
Tower Lift Cylinder
600 ft. lb.
(813 Nm)
200 in. lb.
(23 Nm)
Main Telescope
Cylinder 600 ft. lb.
(813 Nm)
100 in. lb.
(11 Nm)
Tower Telescope
Cyl. - 1st Section
- 2nd Section
600 ft. lb.
(813 Nm)
400 ft. lb.
(542 Nm)
200 in. lb.
(23 Nm)
100 in. lb.
(11 Nm)
Master Cylinder
80 ft. lb.
(108 Nm)
100 in. lb.
(11 Nm)
Platform Level
Cylinder 80 ft. lb.
(108 Nm)
100 in. lb.
(11 Nm)
Steer Cylinder
80 ft. lb.
(108 Nm)
100 in. lb.
(11 Nm)
Axle Extend
Cylinder 100 ft. lb.
(136 Nm)
100 in. lb.
(11 Nm)
Axle Lift
Cylinder 400 ft. lb.
(542 Nm)
N/A