Hitachi NV 65AF3 Technical Data And Service Manual page 21

Problem
(
1) Nails cannot Cylinder inside surface is
be driven. abnormal (packed with
(continued) dust, or worn).
Head valve sliding surface
is abnormal (seized or
damaged, or lubrication is
needed).
Head valve rubber (A) is
abnormal (removed or
damaged).
Head valve spring is
abnormal (fatigued or
damaged).
<Control valve section>
Plunger (A), valve piston
(B), valve bushing (A) or
valve bushing (B) is
abnormal (seized or
damaged).
O-rings or sliding surfaces
are worn or need
lubrication.
Adjuster is raised too high
2) Nails are
for short nails.
driven but
bent.
Nails are not completely fed
into the injection port.
Unspecified nails are used.
Driver blade is worn.
Workpiece is too hard.
3) Nails cannot
Adjuster is incorrectly set.
be driven into
the workpiece
completely:
Air pressure is too low.
the heads
cannot be
made flush.
Workpiece is too hard.
Possible cause
: Most-common cause)
Inspection method
Check that nails can be
2
driven at 5 kgf/cm (4.9 bar,
70 psi).
Perform idle driving to
check the driving
operation.
Perform idle driving to check
that the driver blade is not
held in the down position.
Disassemble the control
valve section and check the
O-rings.
Check that the adjuster is
not raised too high.
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.
Turn the adjuster to the
lowest position and then
drive nails.
Check if a nail is bent even
when driven into soft wood.
--- 18 ---
Remedy
Remove dust and then
lubricate.
Replace the part.
Replace the part.
Apply grease.
Replace the part.
Replace the abnormal part.
Replace the abnormal part.
Apply grease.
Turn the adjuster lower
(lower the pressure).
See item 1).
Replace the part.
Nailer cannot be used
because the material is
beyond its applicable range.
Set the adjuster to the
optimum position.
Adjust air pressure to
5 --- 8.5 kgf/cm 2 (4.9 --- 8.3
bar, 70 --- 120 psi).
Nailer cannot be used
because the material is
beyond its applicable range.