14
4
CYLINDERS
DISASSEMBLY AND ASSEMBLY
4L0AX00CYLINDERS
Inspection and adjustment
Inspection after disassembly
Clean each part thoroughly with cleaning oil, then carry out
the following checks. When a cylinder has been disassem-
bled, replace all the seals with new ones.
1. Piston rod
• Replacetherodiftherearecracks.
• Ifthethreadsaredamaged,repairthemorreplace
the rod.
• If theplating layerof theplated portionis broken,
rusted or scratched, replace the rod.
• Iftherodisbentmorethanthelimitof1mm(0.04
in.)in1m(3.3ft.),replaceit.(Forthemeasurement
method, refer to the figure on the right.)
• Iftheinnerdiameterof theclevisbushingisworn,
replace the bushing.
Measuring the bend
a. Support the portion of the rod with the same diam-
eter at both ends on V-blocks.
b. Set a dial gauge at the center between the two
blocks.
c. Rotatetherodandtakeareadingofthemaximum
and minimum run-out indicated by the dial gauge. If
the bending of the rod is within the above limit, yet is
bent a lot in a small distance so that it will not move
smoothly, replace the rod ifit makes a squeaking
sound in the operation test after reassembly or if it
catches during movement.
2. Tube
• Iftherearecracksintheweldedportion,replacethe
tube.
• Replacethetubeif
theinsidesurfaceisscratchedor
if it leaks hydraulic oil.
• Iftheinnerdiameteroftheclevisbushingisworn,
replace the bushing.
3. Rod cover
• Ifthebushinginnerdiameteriswornandtheclear-
ance with the piston rod is greater than 0.25 mm
(0.0098in.),replacethebushing.
• Iftheinsidesurfaceofthebushingisscratched,and
the scratches are deeper than the depth of the coat-
ing layer, replace the bushing.