JLG 450AJ ANSI Service Manual - Manual (Page 30)

SECTION 2 - PROCEDURES
2-12 – JLG Lift – 3120749
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.
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.
WHEN INSTALLING "POLY-PAK" PISTON SEALS, ENSURE SEALS
ARE INSTALLED PROPERLY. REFER TO WIPER SEAL INSTALLA-
TION FOR CORRECT SEAL ORIENTATION. 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
applicable cylinder head gland groove. Install a new
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.)
Figure 2-10. Rod Seal Installation
Figure 2-11. Wiper Seal Installation
Figure 2-12. Installation of Head Seal Kit