Takeuchi TB 250, Workshop Manual

Page: 343 / 352

5-52
5
TROUBLESHOOTING
CYLINDERS
“4. Disassembly and assembly, Cylinder”
Symptoms Major causes Remedies
Oil leak from the piston rod sliding part
(oil stays on the surface in a ring shape;
this “oil ring” becomes larger and starts
dripping) • Foreign matter is caught in the inter-
nal part of the rod packing or dust
seal
• Flaw or abnormal condition of the in-
ternal lip surface of the rod packing
or dust seal
• Remove the foreign matter.
• Replace the faulty part(s).
• Flaw on the sliding surface of the
piston rod
• Peeling on a hard chromium plated
surface
• Deburr/smooth the sliding surface
with an oilstone (1.6 S or less).
• If the leak still persists after deburr-
ing/smoothing, replace the seals
(e.g., rod packing).
• If the leak still persists after replacing
the seals, replace the piston rod.
• Redo the hard chromium plating.
Oil leak from the rod cover perimeter • O-ring is damaged
• Backup ring is damaged • Replace the faulty part(s).
• Replace the faulty part(s).
Oil leak from the welded part • Tube’s welded part is damaged • Replace the faulty part(s).
Spontaneous drop of cylinder (“spon-
taneous drop” refers to a piston condi-
tion that its maximum movement in 10
minutes is 0.5 mm or more when the
static load is exerted on the rod. The
static load is determined by multiplying
the maximum operating pressure by
the cylinder area) • Foreign matter is caught in the slid-
ing surface of the wear ring
• Flaw or abnormal condition on the
sliding part of the wear ring
• Flaw on the sliding part of the piston
packing
• O-ring is damaged
• Remove the foreign matter.
• Replace the faulty part(s).
• Replace the faulty part(s).
• Replace the faulty part(s).
CYLINDERS