Hitachi NR 83AA3, Technical Data And Service Manual, Page: 23 / 45

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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 head valve
spring.
<Output section>
Air pressure is too low.
Problem
Possible cause Inspection method
Remedy
Check if the nails can be
driven at 5 kgf/cm
2
.
After making idle driving,
check if the driver blade is
kept in the down position.
Disassemble the control
valve and check the O-ring.
Adjust for 5 to 8.5 kgf/cm 2 .
Replace the piston ring.
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).
<
Control valve section >
Plunger (A), Plunger (B) or
valve bushing is abnormal
(galled or damaged).
O-ring is worn or oiling is
needed.
Replace the defective part.
Apply grease or replace.
Nails are not fully fed into
the injection port.
Unspecified nails are used.
Driver blade is worn.
Workpiece is very hard.
2) Nails are bent
when being
driven.
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.
See item 1).
Replace the driver blade.
Do not use unspecified
workpieces.
Set the single actuation/
contact actuation selector to
the contact actuation.
Pull the nail feeder
backward to perform idle
driving. Check if the driver
blade has returned.