Hitachi NR 83A2 Technical Data And Service Manual page 25

Problem
Possible cause
<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).
< Control valve section >
Plunger (A), valve piston
(B), valve bushing (A) or
valve bushing (B) is
abnormal (galled or
damaged).
O-ring is worn or oiling is
needed.
Inspection method
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.
Check if the nails can be
2
driven at 5 kgf/cm .
After making idle driving,
check if the driver blade is
kept in the down position.
Disassemble the control
valve and check the O-ring.
--- 22 ---
Remedy
Adjust for 5 to 8.5 kgf/cm
Replace the piston 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 head valve
spring.
Replace the defective part.
Apply grease or replace.
2
.