JLG 3246ES Service Manual - Manual (Page 115)

SECTION 4 - HYDRAULICS
3121166 – JLG Lift – 4-13
Assembly
NOTE: Prior to cylinder assembly, ensure that the proper cyl-
inder seal kit is used. See your JLG Parts Manual
(3121167).
Apply a light film of hydraulic oil to all components prior
to assembly.
1. A special tool is used to install a new rod seal into
the applicable cylinder head gland groove.
NOTICE
WHEN INSTALLING ‘POLY-PAK’ PISTON SEALS, ENSURE SEALS
ARE INSTALLED PROPERLY. REFER TO WIPER SEAL INSTALLA-
TION FOR CORREC T SEAL ORIENTATION. IMPROPER SEAL
INSTALLATION COULD RESULT IN C YLINDER LEAKAGE AND
IMPROPER CYLINDER OPERATION.
2. Use a soft mallet to tap a new wiper seal into the
applicable cylinder head gland groove. Install a
new wear ring into the applicable cylinder head
glandgroove.
3. Place a new “O-ring and back-up seal in the appli-
cable 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 applica-
ble.
5. Carefully slide the piston spacer on the rod.
NOTE: Upper telescope cylinder piston has an o-ring
installed inside the spacer.
6. If applicable, correctly place new o-ring in the
inner piston 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 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 magnified
insert in Figure 4-9. The split of seals and backup
rings are to be positioned so as not to be in align-
ment with each other.
Figure 4-6. Rod Seal Installation
Figure 4-7. Poly-Pak Piston Seal Installation
Figure 4-8. Wiper Seal Installation
Figure 4-9. Installation of Head Seal Kit