Hitachi NT 65M2 Technical Data And Service Manual page 17

Problem
< Output section >
Air pressure is too low.
Piston O-ring is worn or
damaged.
Piston bumper is abnormal
(dislocated, deformed or
damaged.)
Cylinder ring is abnormal
(dislocated, deformed or
damaged).
Driver blade is abnormal
(deformed, burrs, damaged
or fatigued).
Cylinder's internal surface is
abnormal (deposits of dirt or
worn).
Head valve sliding surface
is abnormal (galled,
damaged or needs oil).
Head valve spring is
abnormal (fatigued or
damaged).
< Control valve section >
Plunger, valve piston, valve
bushing (A) or valve bushing
(B) is abnormal (galled or
damaged).
O-ring is worn or oiling is
needed.
For short nails, the adjuster
2) Nails are bent
is raised too high.
when being
driven.
Nails are not fully fed into
the injection port.
Unspecified nails are used.
Driver blade is worn.
Workpiece is very hard.
Possible cause Inspection method
Pull the nail feeder
backward and perform idle
driving. Check if the driver
blade has returned.
Check if nails can be driven
2
at 5 kgf/cm .
While operating the nailer
without nails, check if the
driving operation is
performed.
After operating the nailer
without nails, check if the
driver blade is kept in the
down position.
After making idle driving,
check if the driver blade is
kept in the down position.
Disassemble the control
valve and check the O-ring.
Check if the adjuster is
raised too high.
See item 1).
Check if the driver blade tip
is abnormally worn.
Drive a nail into soft wood
workpiece and check if the
nail is bent.
--- 14 ---
Remedy
Adjust for 5 to 8.5 kgf/cm
(70 --- 120 psi).
Replace the piston O-ring.
Replace the piston bumper.
Reassemble or replace.
Repair or replace.
Remove the dirt and apply
oil, or replace.
Replace the defective part.
Apply grease.
Replace the defective part.
Apply grease or replace.
Turn the adjuster to the
lower position to decerase
the pressure.
See item 1).
Replace the driver blade.
Do not use unspecified
workpiece.
2