Hitachi NR 1890DC Service Manual page 3

Possible cause
Problem
(*: Most common cause)
2. *• Worn-out piston tip
Nails are *• Broken or worn-out blade
driven but rack
bent.
• Nails are not completely fed
into the injection port.
• Unspecified nails are used.
• Wood material too hard to be
nailed
• Deformed output section
3. • Worn-out piston tip
Nails
cannot be
*• Worn-out piston rack
driven into
the
• Inadequate adjuster control
workpiece
completely:
• Wood material too hard to be
the heads
nailed
cannot be
made flush.
• Weak thrusting force against
wood to be nailed
• Deformed output section
• Insufficient grease on the
cylinder and piston section
• No compressed air in the
nailer
• Compressed air leak
4. *• Abnormal nails are used
Nails jam. (e.g., bent nails, abnormal
collation)
• Nails are not completely fed
into the injection port.
• Worn-out piston tip
• Wood material too hard to be
nailed
Inspection method
• Check the piston tip for
excessive wear.
• Check the blade rack for
break or wear.
• Check whether the
magazine is correctly loaded
with specified nails.
• Drive nails into soft wood
and check whether the
driven nails are bent.
• Check the tips of the
pushing lever and blade
guide for warp, deformation
and excessive wear.
• Check the piston tip for
excessive wear.
• Check the piston rack for
excessive wear.
• Set the adjuster to nail
deeper and then nail again.
• Drive nails into soft wood
and check whether the nail
heads are lifted.
• Firmly thrust the nailer
against wood to be nailed
and start nailing. Check
whether the nail heads are
still lifted.
• Check the nail guide groove
of the pushing lever and
blade guide for any trouble
(e.g., deformation,
excessive wear, burrs).
• Check the greasing
condition of the cylinder and
piston section.
• Fill up the nailer with
compressed air, leave the
nailer still for one day, and
then check the nailing work.
• Check the sealing surfaces,
X-rings, and O-rings inside
the cylinder, piston,
chamber cover, and
chamber base for flaws,
unwanted objects, and other
failures.
• Check whether the
magazine is correctly loaded
with specified nails.
• Check whether the piston tip
is excessively worn.
• Drive nails into soft wood
and check whether nails
jam.
-2-
Corrective action
• Replace defective
parts. See page 23.
• Use specified nails.
• Remove abnormal
nails and load the
nailer with proper
nails.
• This nailer is not for
hard wood.
• Replace defective
parts.
• Replace defective
parts. See page 23.
• Replace defective
parts. See page 23.
• Set the adjuster
properly.
• This nailer is not for
hard wood.
• Follow the nailer
operation guide.
• Replace defective
parts.
• Replenish grease.
• Supply compressed
air.
• Disassemble the
nailer and clean the
chamber, piston, and
their vicinity.
• Replace the sealing
parts.
• Use specified nails.
• Remove abnormal
nails and load the
nailer with proper
nails.
• Replace defective
parts. See page 23.
• This nailer is not for
hard wood.