JLG 1200SJP Service Maintenance Manual page 339

3. Place a new "O-ring and back-up seal in the applicable
outside diameter groove of the cylinder head.
Figure 5-17. Installation of Head Seal Kit
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.
NOTE: Main telescope cylinder piston has an o-ring installed
inside the spacer.
6. If applicable, correctly place new o-ring in the inner pis-
ton diameter groove. (The backup ring side facing 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 piston is recom-
mended to install the solid seal.)
3121142
NOTE: The backup rings for the solid seal have a radius on one
side. This side faces the solid seal.(See magnified insert in
Figure 5-18.)The split of seals and backup rings are to be
positioned so as not to be in alignment with each other.
Figure 5-18. Piston Seal Kit Installation
8. Using suitable protection, clamp the cylinder rod in a
vise or similar holding fixture as close to piston as possi-
ble.
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.
– JLG Lift –
SECTION 5 - HYDRAULICS
5-15