SECTION 4 - BASIC HYDRAULIC INFORMATION & SCHEMATICS
3121788
4-23
4.14 CYLINDER REPAIR
NOTE:
The following are general procedures that apply to
the cylinders on this machine. Procedures that apply
to a specific cylinder will be so noted.
Disassembly
NOTICE
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 port block fitting in the manifold
located on the cylinder.
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.
If applicable, remove the cartridge-type holding
valve and fittings from the cylinder port block.
Discard o-rings.
4.
Place the cylinder barrel into a suitable holding
fixture.
5.
Mark cylinder head and barrel with a center
punch for easy realignment. Loosen the cylinder
head setscrew.
6.
Using the proper wrench, loosen the cylinder
head and remove head from cylinder barrel.
When removing cylinder head do not force if
binding occurs. Reverse rotation a couple times
and try removing again. If still no release, tap
barrel with hammer in threaded area, and try
again. Repeat if necessary, until head is com-
pletely removed.
7.
Attach a suitable pulling device to the cylinder
rod port block end or cylinder rod end, as appli-
cable.
NOTICE
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 BAR-
REL 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.
9.
Using suitable protection, clamp the cylinder rod
in a vise or similar holding fixture as close to the
piston as possible.
10.
Loosen and remove the capscrew(s), if applica-
ble, which attach the tapered bushing to the pis-
ton.
11.
Insert the capscrew(s) in the threaded holes in
the outer piece of the tapered bushing. Progres-
sively tighten the cap screw(s) until the bushing
is loose on the piston.
12.
Remove the bushing from the piston.
13.
Screw the piston CCW, by hand, and remove the
piston from cylinder rod.
14.
Remove and discard the piston o-rings, seal
rings, and backup rings.
ROD SUPPORT
PROTECTED ROD CLAMP
BARREL CLAMP
SUPPORT TABLE
Figure 4-19. Cylinder Barrel Support
SUPPORT TABLE
ROD SUPPORT
Figure 4-20. Cylinder Rod Support
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