Telescope Cylinder - JLG 400S Service And Maintenance Manual

Telescope Cylinder

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
cylinder. Shut down and disconnect the power source.
Adequately support the cylinder rod, if applicable.
3. Remove the capscrews securing the valve block to the
barrel end of the cylinder. Remove the valve assembly.
4. Remove the counterbalance valves, shuttle valve and
plugs from the valve block and cylinder port block. Dis-
card o-rings.
5. Place the cylinder barrel into a suitable holding fixture.
ROD SUPPORT
PROTECTED ROD CLAMP
SUPPORT TABLE
Figure 5-85. Cylinder Barrel Support
3121671
SECTION 5 - BASIC HYDRAULICS INFORMATION & SCHEMATICS
BARREL CLAMP
6. Mark cylinder head and barrel with a center punch for
easy realignment. Using an allen wrench, loosen and
remove the capscrews securing the wearpad plate and
cylinder head to the barrel. Remove the hardware secur-
ing the wear pads to the plate. Remove the wear pads.
BARREL
PUNCH
MARKS
CYLINDER
HEAD
Figure 5-86. Cylinder Head Removal
7. 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.
8. With the barrel clamped securely, apply pressure to the
rod pulling device and carefully withdraw the complete
rod assembly from the cylinder barrel.
Figure 5-87. Cylinder Rod Support
WEAR PAD
WEAR PAD PLATE
CAPSCREW
MAF00340
ROD SUPPORT
SUPPORT TABLE
5-83