JLG 1850SJ Service Manual - Manual (Page 182)

SECTION 5 - BASIC HYDRAULIC INFORMATION & HYDRAULIC SCHEMATICS
5-12 – JLG Lift – 3121619
5.2 HYDRAULIC CYLINDERS
Axle Extend Cylinder
Refer to Figure 5-13.
DISASSEMBLY
CONTAMINATION MAY DAMAGE EQUIPMENT. DISASSEMBLE CYLINDER ON A
CLEAN WORK SURFACE IN A DIRT FREE WORK AREA.
1. Connect a suitable auxiliary hydraulic power source to
cylinder port block fitting.
DO NOT FULLY EXTEND CYLINDER TO THE END OF STROKE.
RETRACT CYLINDER SLIGHTLY TO AVOID TRAPPING PRES-
SURE.
2. Operate hydraulic power source and extend cylinder.
Shut down and disconnect power source. Adequately
support cylinder rod.
3. Remove cartridge-type counterbalance valve and fittings
from cylinder port block. Discard O-rings.
4. Place cylinder barrel in a suitable holding fixture. Tap
around outside of cylinder head retainer with a suitable
hammer to break thread-locking compound.
5. Mark cylinder head and barrel with center punch marks
for later realignment. Remove the capscrews (4).
6. Attach a suitable pulling device to the cylinder rod end.
EXTREME CARE SHOULD BE TAKEN WHEN REMOVING THE
CYLINDER ROD, HEAD, AND PISTON. AVOID PULLING THE
ROD OFF-CENTER, WHICH COULD CAUSE DAMAGE TO THE
PISTON AND CYLINDER BARREL SURFACES.
7. With the barrel clamped securely, carefully withdraw the
complete rod assembly from the cylinder barrel.
8. Using suitable protection, clamp the cylinder rod in a
vise or holding fixture as close to the piston as possible.
ROD SUPPORT
PROTECTED ROD CLAMP
BARREL CLAMP
SUPPORT TABLE
Figure 5-10. Cylinder Barrel Support
Figure 5-11. Capscrew Removal
Figure 5-12. Cylinder Rod Support