JLG 450A_AJ Series II Service Manual - Manual (Page 247)

SECTION 5 - HYDRAULICS
3121290 – JLG Lift – 5-7
ASSEMBLY
NOTE: Use proper cylinder seal kit for cylinder assembly. See your
JLG Parts Manual.
Apply a light film of hydraulic oil to all components before
assembly.
1. Use seal tool to install new rod seal in cylinder head
gland groove.
Figure 5-8. Rod Seal Installation
IMPROPER SEAL INSTALLATION CAN CAUSE CYLINDER LEAKS AND IMPROPER
CYLINDER OPERATION. ENSURE ‘POLY-PAK’ PISTON SEALS ARE PROPERLY
INSTALLED. REFER TO WIPER SEAL INSTALLATION FOR CORRECT SEAL ORIEN-
TATION.
NOTE: Install wiper seal with flat part towards head.
2. Use a soft mallet to tap new wiper seal into applicable
cylinder head gland groove. Install new wear ring into
applicable cylinder head gland groove.
Figure 5-9. Poly-Pak Piston Seal Installation
Figure 5-10. Wiper Seal Installation
3. Place new O-ring and back-up seal in applicable outside
diameter groove of cylinder head.
Figure 5-11. Head Seal Installation
4. Install washer ring on rod. Carefully install head on rod.
Ensure wiper and rod seals are not damaged or dis-
lodged. Push head to rod end.
5. Install two wear rings and piston spacer on rod.
6. Place two new O-rings and back-up rings in inner piston
diameter grooves.
Figure 5-12. Piston Seal Installation