Main Lift Cylinder (Sn 0300243704 To Present, Sn E300005608 To Present) - JLG 400S Service And Maintenance Manual

SECTION 5 - BASIC HYDRAULICS INFORMATION & SCHEMATICS
Main Lift Cylinder (SN 0300243704 to Present,
SN E300005608 to Present)
DISASSEMBLY
DISASSEMBLY OF THE CYLINDER SHOULD BE PERFORMED ON A CLEAN WORK
SURFACE IN A DIRT FREE WORK AREA.
1. Connect a suitable auxiliary hydraulic power source to
the cylinder port block fitting.
DO NOT FULLY EXTEND CYLINDER TO THE END OF STROKE. RETRACT CYLINDER
SLIGHTLY TO AVOID TRAPPING
PRESSURE.
2. Operate the hydraulic power source and extend the cyl-
inder. Shut down and disconnect the power source.
Adequately support the cylinder rod, if applicable.
3. Remove the check valve, cartridge valves, orifice plug
and plugs from the cylinder port block. Discard o-rings.
4. Place the cylinder barrel into a suitable holding fixture.
ROD SUPPORT
PROTECTED ROD CLAMP
SUPPORT TABLE
Figure 5-57. Cylinder Barrel Support
5-70
BARREL CLAMP
5. Mark cylinder head and barrel with a center punch for
easy realignment. Using a hook wrench, unscrew the
cylinder head from the barrel.
BARREL
PUNCH
MARKS
Figure 5-58. Cylinder Head Removal
6. Attach a suitable pulling device to the cylinder rod port
block end or cylinder rod end, as applicable.
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, apply pressure to the
rod pulling device and carefully withdraw the complete
rod assembly from the cylinder barrel.
Figure 5-59. Cylinder Rod Support
CYLINDER HEAD
MAF00230
ROD SUPPORT
SUPPORT TABLE
3121671