Hitachi NR 65AK Service Manual page 21

Problem
(
Air passage is clogged
1) Nails cannot
with broken pieces of
be driven.
piston bumper, etc.
(continued)
2) Nails are
Nails are not completely fed
driven but
into the injection port.
bent.
Unspecified nails are used.
Driver blade is worn.
Workpiece is too hard.
3) Nails cannot
Air pressure is too low.
be driven into
the workpiece
completely:
the heads
Workpiece is too hard.
cannot be
made flush.
Driver blade is worn.
O-ring in the piston is
abnormal (worn or
damaged).
Cylinder inside surface is
abnormal (worn or rough).
Cylinder plate or O-ring is
abnormal (removed,
deformed or damaged).
Head valve sliding surface is
abnormal (seized or
damaged, or lubrication is
needed).
Possible cause
: Most-common cause)
Inspection method
See item 1).
Check that the driver blade
tip is not abnormally worn.
Check if a nail is bent even
when driven into soft wood.
Check if a nail is bent even
when driven into soft wood.
Perform idle driving to check
the driver blade is projected
from the nose tip.
Disassemble the output
section and check the O-ring
and the inside of the cylinder
for abnomality.
Disassemble the cylinder
plate and check for
abnormality.
Check the sliding surface for
abnormality and lubricaton.
--- 17 ---
Remedy
Remove foreign matter.
Replace the piston bumper
with new one.
Body ... Remove foreign
matter in the return
air chamber.
Nose ... Remove foreign
matter in the air
passage and the
feed piston
chamber.
See item 1).
Replace the part.
Nailer cannot be used
because the material is
beyond its applicable range.
Adjust air pressure to 5.4 - --
8.3 bar (5.5 - -- 8.5 kgf/cm
80 - -- 120 psi).
Nailer cannot be used
because the material is
beyond its applicable range.
Replace the part.
Replace the abnormal part.
Replace the abnormal part.
Replace the abnormal part.
Apply grease.
2
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