Service Manual

SECTION 5 - HYDRAULICS
3121202 – JLG Lift – 5-7
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.
WHEN INSTALLING THE WIPER SEAL ON THE LOWER (TOWER)
LIFT CYLINDER, APPLY LOCTITE #609 ON THE WIPER SEAL IN
THREE EVENLY SPACED PLACES TO AID IN RETENTION OF THE
SEAL.
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.
Figure 5-7. Rod Seal Installation
Figure 5-8. Poly-Pak Piston Seal Installation
Figure 5-9. Wiper Seal Installation
Figure 5-10. Installation of Head Seal Kit