JLG 1500SJ Service Manual - Manual (Page 397)

SECTION 5 - HYDRAULICS
3121262 – JLG Lift – 5-45
WHEN INSTALLING NEW SEALS, ENSURE SEALS ARE INSTALLED
PROPERLY. IMPROPER SEAL INSTALLATION COULD RESULT IN
CYLINDER LEAKAGE AND IMPROPER CYLINDER OPERATION.
2. Use a soft mallet to tap a new wiper seal into the cyl-
inder head gland groove. Install new wear rings into
the cylinder head gland groove.
3. Place a new O-ring and backup ring in the outside
diameter groove of the cylinder head.
4. Place the cylinder cap over the rod and carefully
install the head gland on the rod, ensuring that the
wiper and rod seals are not damaged or dislodged.
Push the head along the rod to the rod end.
5. Place a new O-ring and backup rings in the inner
piston diameter groove.
6. Using suitable protection, clamp the cylinder rod in
a vise or similar holding fixture as close to the piston
threads as possible.
7. Install the piston on the cylinder rod hand tight,
ensuring that the o-ring and back-up rings are not
damaged or dislodged.
8. Carefully thread the lock nut onto the rod to secure
the piston in place. Torque to 400 ft.lbs. (542 Nm).
9. Remove the cylinder rod from the holding fixture.
10. Place a new wear ring and t-seal in the outer piston
diameter grooves. (A tube, with I.D. slightly larger
than the O.D.of the piston is recommended to install
the seal.)
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 seals 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.
14. Secure the cylinder head using JLG Threadlocker
(P/N 0100035 and the cylinder cap.
15. After the cylinder has been reassembled, the rod
should be pushed all the way in (fully retracted).
Figure 5-98. Cylinder Head Seal Installation
Figure 5-99. Piston Seal Installation