JLG 740AJ Service Manual - Manual (Page 293)

SECTION 5 - HYDRAULICS
3121160 – JLG Lift – 5-7
NOTE: Install pin into the Gar-Max bearing dry. Lubrication
is not required with nickel plated pins and bearings.
14. Inspect travel limiting collar or spacer for burrs and
sharp edges. If necessary, dress inside diameter
surface with Scotch Brite or equivalent.
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.
NOTE: 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 INSTALLATION 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.
Figure 5-5. Gar-Max Bearing Installation Figure 5-6. Rod Seal Installation
Figure 5-7. Hyrdro-Pak Piston Seal Installation
Figure 5-8. Wiper Seal Installation