JLG M450 ANSI Service Manual - Manual (Page 159)

SECTION 5 - HYDRAULICS
3121127 – JLG Lift – 5-7
wear ring into the applicable cylinder head gland
groove.
3. Place a new o-ring and back-up seal in the applica-
ble outside diameter groove of the cylinder head.
4. Install washer ring onto rod, 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, as applicable.
5. Carefully slide the piston spacer on the rod.
6. If applicable, correctly place new o-ring in the inner
piston diameter groove. (The backup ring side fac-
ing the O-ring is grooved.)
7. If applicable, correctly place new seals and guide
lock rings in the outer piston diameter groove. (A
tube, with I.D. slightly larger than the O.D.of the pis-
ton is recommended to install the solid seal.)
NOTE: The backup rings for the solid seal have a radius on
one side. This side faces the solid seal.(See magni-
fied insert in Figure 5-9.)The split of seals and
backup rings are to be positioned so as not to be in
alignment with each other.
8. Using suitable protection, clamp the cylinder rod in
a vise or similar holding fixture as close to piston as
possible.
9. Carefully thread the piston on the cylinder rod hand
tight, ensuring that the o-ring and back-up rings are
not damaged or dislodged.
10. Thread piston onto rod until it abuts the spacer end
and install the tapered bushing.
NOTE: When installing the tapered bushing, piston and mat-
ing end of rod must be free of oil.
WHEN REBUILDING THE STEER, LOWER LIFT, LEVEL CYLINDER,
OR UPPER LIFT CYLINDER, APPLY LOCTITE #242 TO TAPERED
BUSHING BOLTS, THEN TIGHTEN SECURELY.
Figure 5-7. Wiper Seal Installation
Figure 5-8. Installation of Head Seal Kit
Figure 5-9. Piston Seal Kit Installation