Hitachi NV 45AC Manual

POWER TOOLS
TECHNICAL DATA
AND
SERVICE MANUAL
COIL NAILER
NV 45AC
SPECIFICATIONS AND PARTS ARE SUBJECT TO CHANGE FOR IMPROVEMENT
LIST No. 1098 Nov. 2000
N
MODEL
NV 45AC

Page
CONTENTS
1. PRODUCT NAME.............................................................................................................................. 1
2. MARKETING OBJECTIVE ................................................................................................................ 1
3. APPLICATIONS................................................................................................................................. 1
4. SELLING POINTS ............................................................................................................................. 1
5. SPECIFICATIONS ............................................................................................................................. 2
5-1. Specifications ......................................................................................................................................2
5-2. Nail Selection ......................................................................................................................................3
5-3. Nail Driving Force ...............................................................................................................................4
5-4. Optional Accessories ..........................................................................................................................5
6. COMPARISONS WITH SIMILAR PRODUCTS ................................................................................. 6
7. PRECAUTIONS IN SALES PROMOTION ........................................................................................ 7
7-1. Instruction Manual ..............................................................................................................................7
7-2. Warning Label .....................................................................................................................................7
7-3. Related Laws and Regulations ...........................................................................................................8
8. MECHANISM AND OPERATION PRINCIPLE .................................................................................. 8
8-1. Mechanism .........................................................................................................................................8
8-2. Operation Principle ...........................................................................................................................10
9. TROUBLESHOOTING GUIDE ........................................................................................................12
9-1. Troubleshooting and Correction ........................................................................................................12
9-2. Possible Causes and Corrections of Air Leakage .............................................................................17
10. DISASSEMBLY AND REASSEMBLY ........................................................................................... 19
10-1. General Precautions in Disassembly and Reassembly ..................................................................19
10-2. Disassembly and Reassembly of the Output Section .....................................................................20
10-3. Disassembly and Reassembly of the Control Valve Section ..........................................................22
10-4. Disassembly and Reassembly of the Driving Section ....................................................................25
10-5. Disassembly and Reassembly of the Cap and the Magazine Section ...........................................29
11. INSPECTION AND CONFIRMATION AFTER REASSEMBLY ..................................................... 32
12. STANDARD REPAIR TIME (UNIT) SCHEDULES ........................................................................ 33
[ Appendix]
Assembly Diagram for NV 45AC .............................................................................................................34

--- 1 ---
1. PRODUCT NAME
Hitachi 1-3/4" Coil Nailer, Model NV 45AC
2. MARKETING OBJECTIVE
The current Model NV 45AB coil nailer is well-reputed in the U.S.A. market as a roofing nailer suitable for roofing
asphalt shingles in building construction. However, competitively priced roofing nailers have been put on the
U.S.A. market recently. The newly developed Model NV 45AC is specifically designed for roofing asphalt shingles
and weighs just 1.7 kg (3.7 lbs.). Please expand our market share with the new Model NV 45AC.
The Model NV 45AC is a medium-duty roofing coil nailer capable of asphalt shingles with 25 --- 45 mm length nails
after heavy-duty Model NV 45AB for 22 --- 45 mm length nails.
3. APPLICATIONS
Installation of asphalt roofing shingles in building construction
4. SELLING POINTS
Nailing depth adjustment
mechanism with an easy-
to-see calibrated dial
Rubber grip for comfort and
temperature protection
Rubber protector protects
tool and prevents sliding
Exhaust direction easily
changeable
Lightweight 1.7 kg (3.7 lbs.) for easy one-handed operation

--- 2 ---
Optional accessories
Nail capacity
1.7 kg (3.7 lbs.)
1.0 ltr/cycle at 6.9 bar (1.0 ltr/cycle at 7 kgf/cm2) (0.035 ft3/cycle at 100 psi)
Corrugated cardboard box
3 nails/sec.
Driving speed
241 mm x 269 mm x 124 mm
(9-1/2" x 10-19/32" x 4-7/8")
120 nails (1 coil)
Dimensions
(Length x Height x Width)
Nail feed system
3/8 NPT thread
Standard accessories
Weight
Spiral spring
Air consumption
Air inlet
Package dimensions
(Length x Height x Width)
Packaging
280 mm x 290 mm x 150 mm
(11-1/32" x 11-13/32" x 5-29/32")
Eye protector (Code No. 875769) .............................................................. 1
Hex. bar wrench for M6 screw (Code No. 944459) .................................... 1
Hex. bar wrench for M5 screw (Code No. 944458) .................................... 1
Sequential trip mechanism kit (Single-shot) (Code No. 881973)
Muffler (Code No. 881835)
Shingle guide
Shingle guide (Code No. 878175)
Guide base (Code No. 878176)
Washer (Code No. 949424)
Plate nut (Code No. 878213)
Hexagon socket hd. bolt M5 x 16 (Code No. 949819)
Pneumatic tool lubricant (1 oz oil feeder) (Code No. 877153)
Pneumatic tool lubricant (4 oz oil feeder) (Code No. 872042)
Pneumatic tool lubricant (1 quart can) (Code No. 876212)
5. SPECIFICATIONS
5-1. Specifications
Reciprocating piston type
Model
Driving system
NV 45AC
Operating pressure 4.9 --- 8.3 bar (5 --- 8.5 kgf/cm2, 70 --- 120 psi) (Gauge pressure)

--- 3 ---
10.5 mm
(0.413")
5-2. Nail Selection
The Model NV 45AC utilizes roofing nails which are common round-head nails collated by wire into coils from 120
nails. Applicable nail dimensions are shown below. However, it is recommended to use genuine HITACHI nails to
ensure satisfactory driving quality. For nail length 22 mm (7/8"), recommend the Model NV 45AB instead of this
Model NV 45AC.
CAUTION: Ensure that nails are as specified in Fig. 1. Other nails will cause clogging of nails and
subsequent damage to the nailer.
3.05 mm
(0.120")
25 mm (1")
Min.
Wire-collated nails
Fig. 1 Dimensions of nails
Max.
10.5 mm
(0.413")
45 mm (1-3/4")
3.05 mm
(0.120")

--- 4 ---
Porter Cable RN175
Senco SCN40R
Hitachi NV 45AB
5-3. Nail Driving Force
Fig. 2 shows by type of wood and nail the nailer output energy provided by the supply pressure and the nailing
energy required for driving the nail flush. Air pressure which exceeds the intersecting point between the nailer
output energy and the required nailing energy for driving the nail allows the nail to be fully driven.
For example, when driving a nail of 3.05 mm dia. x 45 mm length (0.120" x 1-3/4") into a workpiece of hemlock
with the Model NV 45AC, a pressure of about 6.9 bar (7 kgf/cm2, 100 psi) allows the nailer to drive the nail flush
with the wood surface. A pressure beyond this value causes the nail head to be driven below the wood surface.
Fig. 2 should be used as a reference only because those values vary depending on the type of wood, moisture
content, and grain of wood.
Fig. 2 Required nailing energy and nailer output energy
Max CN450R
Bostitch N63CP
NV 45AC
Hemlock

--- 5 ---
5-4. Optional Accessories
(1) Sequential trip mechanism kit
The sequential trip mechanism kit is provided as an optional accessory for the Model NV 45AC. When using
this optional accessory, a nail is driven by pressing the push lever first against a workpiece and then pulling
the trigger, and no nail is driven when pulling the trigger first and then pressing the push lever against a
workpiece (single-shot operation). Please recommend the sequential trip mechanism kit to customers who
may want to use it. Salespersons must instruct the customers to read thoroughly the Instruction Manual
attached to the sequential trip mechanism kit and also the Handling Instructions of the Model NV 45AC for
correct use.
(2) Muffler
The muffler is provided as an optional accessory for the Model NV 45AC. By mounting this muffler, the
exhaust sound is reduced by about 10 dB (A). Please recommend the muffler to customers who may want to
use it. The muffler can be mounted according to the following procedure as shown in Fig. 3.
1. Remove the hex. socket hd. bolt M5 x 10.
2. Put the muffler in the head ring with the convex side facing the top cover.
3. Fit the convex portion of the exhaust cover in the concave portion of the top cover.
4. Secure it with the hex. socket hd. bolt M5 x 10.
Exhaust cover
Washer
Top cover
Concave portion of top cover
Muffler
Head ring
Convex portion of muffler
Convex portion of exhaust cover
Hex. socket hd. bolt
M5 x 10
Fig. 3 Mounting of muffer

--- 6 ---
Maker BOSTITCH
HITACHI SENCO PORTER CABLE MAX
Air consumption at 6.9
bar (7 kgf/cm2, 100 psi)
Operating pressure
Driving depth
adjustment mechanism
Direction change of
exhaust air
Magazine type
(Material)
Tool not required
Weight
Dimensions
(L x H x W)
Replaceable anti-slip
protector
Trigger lock mechanism
Exhaust muffler
Handle grip
Shank dia.
Applicable
nails
Head dia.
Collation
Length
4.9 --- 8.3 bar
(5 --- 8.5 kgf/cm2)
(70 --- 120 psi)
241 mm x 269 mm x 124 mm
(9-1/2" x 10-19/32" x 4-7/8")
250 mm x 264 mm x 124 mm
(9-27/32" x 10-13/32" x 4-7/8")
277 mm x 269 mm x 117 mm
(10-29/32" x 10-19/32" x 4-19/32")
248 mm x 264 mm x 117 mm
(9-3/4" x 10-13/32" x 4-19/32")
Model name
25 mm -- 45 mm
(1" -- 1-3/4")
NV 45AC NV 45AB RN45B SCN40R RN175 CN450R
4.9 --- 6.9 bar
(5 ---7 kgf/cm2)
(70 --100 psi)
4.9 --8.3 bar
(5 --8.5 kgf/cm2)
(70 --120 psi)
4.9 --8.3 bar
(5 --8.5 kgf/cm2)
(70 --120 psi)
4.5 -- 6.9 bar
(4.6 -- 7 kgf/cm2)
(65 --100 psi)
1.0 ltr/cycle
(0.035 ft3/cycle) 1.2 ltr/cycle
(0.042 ft3/cycle) 1.8 ltr/cycle
(0.064 ft3/cycle) 1.3 ltr/cycle
(0.046 ft3/cycle) 1.4 ltr/cycle
(0.049 ft3/cycle) 2.0 ltr/cycle
(0.070 ft3/cycle)
120 nails 120 nails 120 nails 120 nails 120 nails
Bottom loading
(Plastic) Top loading
(Plastic) Top loading
(Plastic) Top loading
(Plastic) Top loading
(Plastic)
Nail capacity
None Tool required None Tool not required None
Provided
None
Provided
Tool not required Tool not required Tool not required
Provided Provided None
None
None
Racket grip
(Comfortable grip)
Wire
10.5 mm (0.413")
3.05 mm (0.120")
None
Rubber
(Not elastic)
Wire
3.05 mm (0.120")
None
Provided
Foam rubber
(Apt to peel off)
Wire
None
None
Rubber
(Not elastic)
Wire
Provided
Provided
Rubber
(Not elastic)
Wire
10 mm (0.394")
3.05 mm (0.120")
19 mm --- 38 mm
(3/4" --- 1-1/2")
9.8 mm (0.385")
3.05 mm (0.120")
22 mm -- 45 mm
(7/8" -- 1-3/4")
10.5 mm (0.413")
3.05 mm (0.120")
19 mm -- 45 mm
(3/4" -- 1-3/4")
10.5 mm (0.413")
19 mm -- 45 mm
(3/4" -- 1-3/4")
22 mm -- 45 mm
(7/8" -- 1-3/4")
1.7 kg (3.7 lbs.) 2.5 kg (5.5 lbs.) 2.7 kg (6.0 lbs.) 2.4 kg (5.3 lbs.) 2.3 kg (5.1 lbs.) 2.5 kg (5.5 lbs.)
None
Optional
275 mm x 268 mm x 111 mm
(10-13/16" x 10-9/16" x 4-3/8")
300 mm x 257 mm x 110 mm
(11-13/16" x 10-1/8" x 4-11/32")
6. COMPARISONS WITH SIMILAR PRODUCTS
Tool not required Tool not required
None

--- 7 ---
7. PRECAUTIONS IN SALES PROMOTION
In the interest of promoting the safest and most efficient use of the Model NV 45 AC Nailer by all of our customers,
it is very important that at the time of sale the salesperson carefully ensures that the buyer seriously recognizes
the importance of the contents of the Instruction Manual, and fully understands the meaning of the precautions
listed on the Warning Label attached to each tool.
7-1. Instruction Manual
Although every effort is made in each step of the design, manufacture, and inspection to provide protection
against safety hazards, the dangers inherent in the use of any pneumatic tool cannot be completely eliminated.
Accordingly, general precautions and suggestions for use of pneumatic tools, and specific precautions and
suggestions for the use of the pneumatic nailer are listed in the Instruction Manual to enhance the safe, efficient
use of the tool by the customer.
Salespersons must be thoroughly familiar with the contents of the Instruction Manual to be able to offer
appropriate guidance to the customers during sales promotion.
7-2. Warning Label
Each Model NV 45AC unit is provided with a Warning Label (illustrated below) which lists basic safety precautions
in its use. Carefully ensure that customers fully understand and follow these precautions before using the tool.

--- 8 ---
7-3. Related Laws and Regulations
As nailers and staplers are designed to instantaneously drive nails and staples, there is an ever-present danger of
misfiring and subsequent possible serious injury. Accordingly, close attention in handling is absolutely necessary
at all times. Carefully ensure that the customer is fully aware of the precautions listed in the Instruction Manual
provided with each unit.
While there are no specific safety regulations, there are related items in various general safety regulations with
which the salespersons should be familiar in order to properly advise the customer. Please check your national
and/or local regulations for applicable items. Some applicable items are outlined below.
The U.S.A:
OSHA 1926.102 Eye and face protection
1926.302 Power-operated hand tools
ANSI SNT-101-1993 Portable, Compressed-Air-Actuated,
Fastener Driving Tools-Safety Requirements for
8. MECHANISM AND OPERATION PRINCIPLE
8-1. Mechanism
As illustrated in Fig. 4, NV 45AC can be generally divided into four sections: output section, control valve section,
driving section and magazine section. Most of the parts of the above sections have been newly designed, though
its basic construction is the same as that of the Model NV 50AG. Primary differences from the Model NV 50AG
are described below.
Output section ................... Most of the parts have been newly designed, though its basic construction is the
same as that of the Model NV 50AG. The piston unit employs O-rings at the
sliding portion in the same manner as the Model NV 45AB instead of a piston
ring. The protector has been newly designed to prevent slipping of tool.
Control valve section .......... This section is common to the Models NR 90AC and NV 65AH.
Driving section .................... The adjuster has been newly designed to improve operability in nailing depth
adjustment.
The plastic guard shielding the pushing lever and the feed piston has been newly
designed to prevent adhesion of dust.
Magazine section ................ This section is common to the Model NV 45AB, though the shingle guide is not
provided. The shingle guide is interchangeable between the Model NV 45AB and
the Model NV 45AC.

--- 9 ---
Fig. 4 Construction
Top Cover [3]
Accumulator
Piston [14]
(Drive Blade)
Exhaust
Cover [8]
Head Valve (A) [12]
Head Ring [4]
Exhaust Vent
Cylinder [19]
Piston
Bumper [20]
Adjuster [71]
Nose [36]
Guard [32]
Feeder [41]
Pushing
Lever (A) [42]
Protector [5]
Control valve
section
Plunger Spring [61]
Plunger (A) [62] Valve Bushing (A) [64]
Valve Bushing (B) [55]
Valve Piston (B) [59]
Nail Stopper (B) [86]
Magazine Cover [102]
Nail Holder [99]
Cap [49]
Body Ass'y [21]
Nail Stopper (A) [84] Nail Guide [83]
Guide Lock [81]
Feed Piston [73]
Feeder [41]
Magazine
Stopper [93]
Magazine section
Trigger (A) [25] Magazine [95]
Driving section Output section

--- 10 ---
Control valve
section
Fig. 5
Fig. 6 Control valve section
8-2. Operation Principle
(1) Before nailing: (Fig. 5 and Fig. 6)
1) When compressed air is fed to the main body,
it fills the accumulator ( ).
2) At the same time, the compressed air flows into
the valve piston lower chamber of the control
valve section and forces Valve Piston (B) [59]
upward. Also, the compressed air is fed through
the air supply vent and air passage to the head
valve chamber. As a result, the Head Valve Spring
[10] is pushed down together to seal Head
Valve (A) [12] and Cylinder [19].
(2) When nailing: (Fig. 5 and Fig. 6)
1) When Pushing Lever (A) [42] and Trigger (A) [25]
are operated together and Plunger (A) [62] is
pushed upward, the compressed air in the valve
piston lower chamber is discharged from the
bottom of Plunger (A) [62]. As a result, the
compressed air in the accumulator ( ) pushes
down Valve Piston (B) [59], blocking the air
supply vent and opening the exhaust valve.
2) When the exhaust valve opens, the compressed
air in the head valve chamber is discharged into
the atmosphere through the air passage.
3) When the air pressure applied on the bottom
surface of Head Valve (A) [12] overcomes the
strength of the Head Valve Spring [10], Head
Valve (A) [12] is pushed upward. At this time,
Head Valve (A) [12] seals the Exhaust Cover [8],
blocking the passage to the exhaust vent.
4) When Head Valve (A) [12] goes up, the
compressed air in the accumulator flows rapidly
into the Cylinder [19], forcing the Piston [14]
downward to strike the nail. When the Piston
[14] passes the cylinder hole, the compressed air
flows into the return air chamber and is
accumulated there.
Air supply vent
To the head valve chamber
Air passage
Trigger (A) [25]
Nail
Cylinder hole
Cylinder [19]
Piston [14]
Accumulator
Head Valve (A) [12]
Head Valve
Spring [10]
Exhaust vent
Head valve
chamber
Exhaust Cover [8]
Valve piston
lower chamber
Valve Piston (B) [59]
Air
passage Accumulator
Return air
chamber
Pushing Lever (A) [42]
Exhaust
valve
Plunger (A) [62]

--- 11 ---
(3) During return: (Fig. 7 and Fig. 8)
1) When either Pushing Lever (A) [42] or Trigger
(A) [25] is released, Plunger (A) [62] goes down
and the compressed air in the accumulator
flows into the valve piston lower chamber.
2) As the air pressure in the valve piston lower
chamber increases to overcome the air
pressure applied on the upper portion of Valve
Piston (B) [59], Valve Piston (B) [59] is forced
upward. When this occurs, the exhaust valve is
closed and the air supply vent is opened.
3) When the air supply vent opens, the compressed
air in the accumulator ( ) passes through the
air passage and flows into the head valve
chamber to push down Head Valve (A) [12].
As a result, Head Valve (A) [12] and Cylinder
[19] are sealed and, at the same time, Head
Valve (A) [12] and Exhaust Cover [8] are
released to open the exhaust vent.
4) The compressed air at the upper portion of the
Piston [14] is discharged into the atmosphere
through the exhaust vent. In this way, the air
pressure at the upper portion of the Piston [14]
is reduced, and the greater pressure of the air
accumulated in the return air chamber pushes
the Piston [14] upward.
5) If the air pressure at the lower portion of the
Piston [14] is higher than that of the
atmosphere after the Piston [14] has fully
returned, the excess air pressure is discharged
into the atmosphere through the clearance
between the Piston Bumper [20] and the driver
blade.
Fig. 7
Control valve
section
Air passage
Trigger (A) [25]
Nail
Driver blade
Cylinder [19]
Accumulator
Head Valve (A) [12]
Exhaust vent
Head valve
chamber
Exhaust Cover [8]
Return air
chamber
Pushing Lever (A) [42]
Fig. 8 Control valve section
Air supply
vent
To the head valve chamber
Plunger (A) [62]
Valve piston
lower chamber
Valve Piston (B) [59]
Air
passage Accumulator
Exhaust valve
Piston [14]
Piston
Bumper [20]

--- 12 ---
Problem Possible cause
( : most-common cause) Inspection methods Remedy
9. TROUBLESHOOTING GUIDE
9-1. Troubleshooting and Correction
1) Nails cannot
be driven.
<Nails>
Magazine is not loaded with
specified genuine nails.
Magazine is loaded with
abnormal nails (bent nails,
too large or too small nail
heads, abnormal collation,
others).
Nails or link pieces are
jammed.
Link pieces are deformed or
broken.
<Driving section: Nose, feeder,
feed piston, etc.>
Sliding resistance of the
feed piston is too high.
Nail guide face of the nose
is abnormal (deformed,
burrs or damaged).
Spring or feeder spring is
abnormal (damaged or
fatigued).
Feeder is abnormal
(damaged or worn).
Nails are not correctly
loaded in the groove of the
nose.
Dust sticks to the feeder
sliding portion of the nose,
or lubrication is needed.
Air pressure is too low.
Air passage is clogged
with broken pieces of
piston bumper, etc.
Feeder piston chamber
contains foreign matter
such as broken pieces of
piston bumper, etc.
Check that the magazine is
correctly loaded with
specified nails.
Check that the driving
section is not abnormal
(burrs, deformed, damaged
or worn).
Remove the feed piston
and check the feed piston
sliding surface of the
nose.
Check that nails are
correctly loaded in the
groove of the nose.
Open the nail guide and
perform idle driving to check
the feeder's operation.
Use specified nails.
Remove the abnormal nails
and load the nailer with
proper nails.
Apply grease to the sliding
surface.
Polish the scratched portion
with sandpaper. Replace
the parts.
Deburr the nail guide face.
Correct the deformed part.
Replace the abnormal parts.
Remove dust and then
lubricate the sliding surface.
Adjust the air pressure to
4.9 --- 8.3 bar (5 --- 8.5 kgf/cm
2
,
70 --- 120 psi).
Remove foreign matter.
Replace the piston bumper
with new one.
Body ... Remove foreign
matter in the return
air chamber.
Nose ... Remove foreign
matter in the air
passage and the
feed piston
chamber.
Load nails in the correct
position in the nose.

--- 13 ---
1) Nails cannot
be driven.
Air leaks from the gap
between the body and the
nose.
O-rings are worn or
deformed.
O-rings need lubrication.
<Nail guide section>
Nail guide face is abnormal
(deformed, burrs or
damaged).
Dust stickes to the inside of
the nail guide groove, or
lubrication is needed.
Spring is abnormal (missing,
damaged or fatigued).
The claw ridge section of the
nail stopper is abnormal
(damaged, worn or burrs).
<Magazine section>
<Pushing lever>
Magazine
Pushing lever
<Output section:piston, driver
blade, etc.>
Air pressure is too low.
O-ring in the piston is
abnormal
(worn or damaged).
Piston bumper is abnormal.
O-ring in the cylinder is
abnormal (removed, deformed
or damaged).
Driver blade is abnormal
(deformed, burrs or damaged).
Check that the nail guide is
not abnormal (worn,
deformed, damaged, etc.).
Check the operation of nail
stopper (A) and nail stopper
(B).
Tighten screws and check
the O-rings.
Replace the O-rings.
Apply grease or lubricate.
Correct or replace the parts.
Remove dust and then
lubricate.
Replace the abnormal parts.
Collate the nails correctly
and reload the nailer with
them.
Remove burrs or deformed
part. Replace the parts.
Adjust the height of the nail
holder correctly.
Correct or replace the parts.
Adjust the air pressure to
4.9 -- 8.3 bar (5 -- 8.5 kgfcm2,
70 -- 120 psi).
Replace the O-ring.
Replace the piston bumper.
Reassemble or replace the
parts.
Correct or replace the part.
Problem Possible cause
( : most-common cause) Inspection methods Remedy
Check that a nail does not
catch on another nail in the
magazine.
Check that a nail does not
catch on some part of the
magazine.
Check the height of the nail
holder.
Check the operation of the
pushing lever.
Open the nail guide and
perform idle driving to check
that the driver blade is
returned.

--- 14 ---
Cylinder inside surface is
abnormal (packed with dust,
or worn).
Head valve sliding surface is
abnormal (seized or
damaged, or lubrication is
needed).
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-ring or sliding surface is
worn or needs lubrication.
Adjuster is raised too high
for short nails.
Nails are not completely fed
into the injection port.
Unspecified nails are used.
Driver blade is worn.
Workpiece is too hard.
Adjuster is incorrectly set.
Air pressure is too low.
Workpiece is too hard.
Problem Possible cause
( : most-common cause) Inspection methods Remedy
1) Nails cannot
be driven.
(continued)
Check that nails can be
driven at 4.9 bar (5 kgf/cm2,
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.
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
4.9 --- 8.3 bar
(5 --- 8.5 kgf/cm2, 70 ---120 psi).
Nailer cannot be used
because the material is
beyond its applicable range.
2) Nails are
driven but
bent.
3) Nails cannot
be driven into
the workpiece
completely:
the heads
cannot be
made flush.
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.

--- 15 ---
Problem Possible cause
( : most-common cause) Inspection methods Remedy
Driver blade is worn.
O-ring in the piston is
abnormal (worn or
damaged).
Cylinder inside surface is
abnormal (worn or rough).
Cylinder plate or O-ring is
abnormal (removed,
deformed or damaged).
Head valve sliding surface is
abnormal (seized or
damaged, or lubrication is
needed).
<Nails>
Unspecified nails are used.
Abnormal nails are mixed.
Nail heads are too large or
too small.
Collating wires are abnormal
(broken, welding failed,
deformed or welding position
failed).
Collating wires are
deformed (deformed in
collation angle or collation
pitch).
3) Nails cannot
be driven into
the workpiece
completely:
the heads
cannot be
made flush.
(continued)
Perform idle driving to check
the driver blade is projected
from the nose tip.
Disassemble the output
section and check the
O-ring and the inside of the
cylinder for abnormality.
Disassemble the cylinder
plate and check for
abnormality.
Check the sliding surface for
abnormality and lubrication.
Check if the specified nails
are used.
Check the nails as follows.
Replace the part.
Replace the abnormal part.
Replace the abnormal part.
Replace the abnormal part.
Apply grease.
Use specified nails.
Remove the abnormal nails
and load the nailer with
proper nails.
4) Nails jam.
16˚
L2
8
(0.315)
10.5
(0.413)
30.5
(0.120)
L1
UNIT: mm (inch)
Type L2 L1
7
(0.276) 16
(0.630)
7
(0.630) 25
(0.984)
A
B

--- 16 ---
Problem Possible cause
( : most-common cause) Inspection methods Remedy
<Body: Nail feeding is
incomplete.>
Feeder is worn and the
sliding section is abnormal.
Nail guide face of the nose
or the sliding section of the
feeder is abnormal
(deformed, burrs or
damaged).
Spring or feeder spring is
abnormal (damaged,
fatigued or removed).
<Body: Nail guide section>
Nail guide section is
abnormal.
<Driver blade is not returned
completely.>
See item "1) Output section:
piston, driver blade, etc.".
Air pressure is too high.
4) Nails jam.
(continued)
Open the nail guide and
check the position of the
feeder claw. Check that the
feeder claw holds a nail, and
the first nail is positioned in
the injection port. (Check
that the second claw holds
the nail shaft and feeds it.)
See item "1) Nail guide
section".
Perform idle or actual
driving to check if the driver
blade is returned
completely.
Nails may be jammed if
driven at a high pressure
and high speed. Check
pressure and driving speed.
Replace the abnormal part.
See item "1) Nail guide
section".
See item "1) Output section:
piston, driver blade, etc.".
Adjust the air pressure to
4.9 --- 8.3 bar (5 -- 8.5 kgf/cm2,
70 --120 psi).

--- 17 ---
Head Valve (A) [12] is abnormal ((a)
portion is worn, deformed or broken).
The Exhaust Cover [8] is abnormal ((a)
portion is deformed or clogged with
dust).
The Hex. Socket Hd. Bolt M5 x 22 [6]
is loose.
Gasket (A) [9] is damaged.
The seal surface of the Body Ass'y [21]
or the Exhaust Cover [8] is abnormal.
9-2. Possible Causes and Corrections of Air Leakage
Air leakage repair location
(A)
Repair procedure
(1) Check the points of the
following parts marked
by an asterisk for
abnormal condition.
(2) Next, check the seal
parts (marked with a
double circle) for wear,
flaws or damage.
(3) And then, check other
places.
(B)
e
fg
d
c
b
h
(E)
(E)
(D)
(C)
(C)
(F) (G)
a
(A) Exhaust port Head Valve (A) [12] and Cylinder [19]
are abnormal (seal surface of the (b)
portion is worn or deformed).
The Head Valve O-ring [11] is abnormal
(worn, deformed or damaged).
Head Valve (A) [12] is abnormal (worn,
deformed or damaged).
(B) Exhaust cover
Air leakage points Possible cause
With control valve OFF With control valve ON
(H)
Nail feeder section Control valve section

--- 18 ---
The Cylinder O-Ring (1AS-50) [15] of
the Cylinder Plate [16] is abnormal
(broken or damaged).
The O-Ring (S-36) [17] of the Cylinder
[19] is abnormal (broken or damaged).
The seal surface of the Body Ass'y [21],
Cylinder Plate [16] or Cylinder [19] is
abnormal ( c or d portion).
The O-Ring [60] on Valve Piston (B)
[59] is abnormal (worn, broken or
damaged).
The lower O-Ring [57] on Valve Piston
(B) [59] is abnormal (worn, broken or
damaged).
The O-Ring (S-18) [56] on Valve
Bushing (B) [55] is abnormal (broken or
damaged).
The inside surface of the valve chamber
of the Body Ass'y [21] is abnormal.
The O-Ring [63] on Plunger (A) [62] is
abnormal (worn, broken or damaged).
Valve Bushing (A) [64] is abnormal
(sliding surface of Plunger (A) [62] is
deformed or scratched).
(C) Nose (I) The O-Rings [24] [31] of the Body Ass'y
[21] are abnormal (broken or
damaged).
The Nylock Bolt (W/Flange) M6 x 25
[35] is loose.
The seal surface of the Body Ass'y [21]
or the Nose [36] is abnormal (broken,
deformed or scratched).
The Piston Bumper [20] is abnormal
( e or f portion is damaged,
deformed or cracked).
The Piston [14] is abnormal (driver
blade or sealed face is deformed).
The f surface of the Body Ass'y [21]
is deformed.
The O-Ring (P-18) [74] on the Feed
Piston [73] is abnormal (worn, broken
or damaged) or the Nose [36] is worn,
deformed or scratched on the sliding
surface.
The O-Ring (P-9) [72] in the Nose [36]
is abnormal (worn, broken or damaged)
or the Feed Piston [73] is worn,
deformed or scratched on the sliding
surface.
The upper O-Ring [57] on Valve Piston
(B) [59] is abnormal (worn, broken or
damaged).
The Head Valve O-Ring [11] on Valve
Bushing (B) [55] is abnormal (broken or
damaged).
The top surface of the valve chamber of
the Body Ass'y [21] is abnormal ( g
portion).
The inside of the O-Ring (S-4) [58] on
Valve Piston (B) [59] is abnormal (worn,
broken or damaged).
Plunger (A) [62] is abnormal (sliding
surface is deformed or scratched).
The O-Ring [48] is abnormal (worn, broken or damaged).
The Cap [49] is loose.
The seal surface of the Body Ass'y [21] or the Cap [49] is abnormal (broken,
deformed or scratched).
(D) Nose (II)
(E) Feed piston
(F) Control valve (I)
(G) Control valve (II)
(H) Cap
Air leakage points Possible cause
With control valve OFF With control valve ON