Makita Gas nailer GN900SE Manual

Models No.
Description
PRODUCT
TECHNICAL INFORMATION
CONCEPT AND MAIN APPLICATIONS
Specification
P 1/ 16
Standard equipment
Dimensions: mm (")
Width*2(W)
*2 with Hook
Height (H)
Length*2(L)
108 (4-1/4)
321 (12-5/8)
368 (14-1/2)
Note: The standard equipment for the tool shown above may differ by country.
GN900
Cordless Clipped Head Framing Nailer
Model GN900 is a cordless clipped head nailer developed for a wide range of
framing applications. The main features are as follows:
Using fuel gas as the power source to provide freedom from hoses and compressors
Equipped with LED indication lamp with battery power warning and trouble detection
functions for convenience of operation and repair
Safety goggles ............................ 1
Hex wrench 4 ............................. 1
Plastic carrying case ................... 1
Magazine capacity
Nail
44 nails (1 strip)
50 - 90
(2 - 3-1/2)
2.9 - 3.3
(0.113 - 0.131)
Clipped-head
Length: mm (")
Gauge (Shank diameter): mm (")
Head type
34 degreeNail collation angle
Optional accessories
Nail fuel pack
Fuel cell
Cleaner kit (contains the following accessories in a special Tool bag: Cleaner/ 1, Lubricating oil/ 1,
Hex wrench 4/ 1, Brush/ 1, Cotton waste/ 1)
Charger DC07SA
Charger DC10WA
Battery BL7010
7.2
1.0
30
with DC07SA/DC10WA
Li-ion
Charging time (approx.): min.
Battery
YesAnti-dry-fire mechanism
Cell
Voltage: V
Capacity: Ah
Battery life*4
Fuel cell life*5
4,000 nails (approx.)
Motor*3Coreless DC motor
1,200 nails (approx.)
3.2 (7.0)
3.4 (7.5)
without Battery and Fuel cell
with Battery and Fuel cell
Net weight: kg (lbs)
W
H
L
This product is available in the following variations.
The model also includes the accessories listed below in "Standard equipment".
GN900SE
GN900S DC07SA
Model No. type
No
Charger
No
quantity
No
1
2
BL7010
(Li-ion 1.0Ah)
Battery*1
GN900ZK
*3 The motor is used for gas mixing, air intake/exhaust, supply of cooling air.
*4 Battery life: the number of nails on a single full battery charge
*5 Fuel cell life: the number of nails per Fuel cell
*1 Battery is used as the power source for ignition spark,
gas mixing, air intake/exhaust and supply of cooling air.

P 2/ 16
Repair
CAUTION: 1) Remove Battery, Fuel cell, Nail from the machine for safety before repair/ maintenance
in accordance with the instruction manual!
2) Loosen Hex socket head bolts with L-shape wrench in advance before removing them
using cordless impact driver with 1R228/ 1R229, or the top of 1R228/ 229 will damage.
[1] NECESSARY REPAIRING TOOLS
[2] LUBRICATIONS AND ADHESIVES
Fig. 1
Code No. Description Use for
1R005 Retaining ring pliers RT-2N Disassembling / Assembling Retaining ring R-58
1R228 1/4” Hex shank bit for M4 Disassembling / Assembling M4 Hex socket head bolt
1R229 1/4” Hex shank bit for M5 Disassembling / Assembling M5 Hex socket head bolt
1R268 Spring pin extractor 3 Disassembling / Assembling Spring pin 3-32
1R291 Retaining ring S and R pliers Disassembling / Assembling Retaining ring R-24
Item No.
Apply a little amount of Lubricant and Adhesives illustrated in Fig. 1.
Description Portion to lubricate Lubrication
Lubrication oil VG100
Lubrication oil VG100
Molybdenum
disulfide
a: Inside with which Driver complete contacts
b: Outside with which Chamber contacts
24
42
23
Cylinder ring Whole portion
O ring 60 Whole portion
Cylinder
24
b
b
42
23
17
9
c
67
97
a
ThreeBond1342
or
Loctite272
c: Rib portion on which
Exhaust plate is attached
23 Cylinder
Item No. Description Adhesive
ThreeBond
1215
Portion to glue
Thread
Driver complete
Exhaust plate
Chamber
M5x10 Hex
socket head bolt
M5x16 Hex
socket head bolt
M5x35 Hex
socket head bolt
9
97
17
67

P 3/ 16
Repair
[3] DISASSEMBLY/ASSEMBLY
[3]-1. Driver, Front cushion
DISASSEMBLING
1) Remove M5x35 Hex socket head bolt (2pcs.)
Note: Sleeve 8 (2pcs.) may be
fallen from Handle set
in the disassembling step.
Therefore, pay attention
not to lose Sleeve 8.
1) Remove Retaining ring (INT) R-58 from Cylinder with 1R005.
2) Remove M5x25 Hex socket head bolt (4pcs.) and Top cap.
3) Hold Housing by hand and slide it straightly
and gently in order not to hook with Fan 60,
then lift Housing obliquely as designated in
black arrow.
Note: Do not deform Fan 60.
Handle set
Top cap
Cylinder head
Fan 60
M5x35 Hex socket
head bolt (2pcs.)
M5x25 Hex socket
head bolt (4pcs.)
Housing
(1) Disassemble Driver complete as illustrated in Figs. 2 and 3.
Fig. 2
Fig. 3
Sleeve 8
cylinder 1R005 Driver complete
Retaining ring (INT) R-58 on Cylinder
3) While holding Piston ring (2pcs.)
with the slotted screwdriver to
prevent them from being caught
in the groove for Retaining ring
(INT) R-58, push Driver complete
with another slotted screwdriver
toward Top cap side.
2) Insert slotted screwdriver along with
an vertical groove of Cylinder.
slotted
screwdriver
vertical groove
of Cylinder
Cylinder viewed from top cap side
Inside view
slotted screwdriver
end of Driver complete
Piston ring (2pcs.)
on Driver complete

P 4/ 16
Repair
[3] DISASSEMBLY/ASSEMBLY
[3]-1. Driver, Front cushion (cont.)
DISASSEMBLING
ASSEMBLING
M5x10 Hex socket
head bolt (2pcs.)
Separate Cylinder section from Housing after removing
Arm plate, Contact top and Front plate.
(2) Separate Cylinder section from Housing. And then disassemble Front cushion. (Fig. 4)
(1) Assemble Front cushion to Cylinder as illustrated in Fig. 5.
(2) Mount two Piston rings to Driver complete. (Fig. 6)
M5x16 Hex socket
head bolt (3pcs.)
Arm plate
Contact top
Front plate
Housing
Front cushion
Push Front cushion into Cylinder
with hammer until it stops.
Insert slotted screwdriver
from the nail exit side,
and push Front cushion
out of Cylinder section.
Fig. 4
Cylinder
section
Front cushion
hammer
more than
90 degrees
Assemble Piston ring (2pcs.) to Driver complete
so that the angle of their slits is more than 90 degrees.
slit
slit
slit
slit
Cylinder
Driver complete
Fig. 5 Fig. 6
Contact top Contact top
Use slotted screwdriver to prevent
Piston rings from being caught in
the groove of Cylinder for
Retaining ring (INT) R-58.
(Refer to Fig. 3.)
Set Driver complete in place
so that the flat tip faces
Contact top installation side.
Note: Do not face the chamfered tip
of Driver complete to Contact top
installation side
(3) Insert Driver complete into Cylinder as illustrated in Fig. 7.
(4) Inserting Cylinder section into Housing, tighten Front plate with M5x16 Hex socket head bolt (3pcs.).
Assemble Contact top and Arm plate. (Fig. 4)
(5) Assemble Retaining ring (INT) R-58 to the groove in Cylinder. (Fig. 3)
(6) Assemble Handle set to Housing. (Fig. 2)
Fig. 7

P 5/ 16
Repair
[3] DISASSEMBLY/ASSEMBLY
[3]-2. Exhaust valve section
DISASSEMBLING
When the tip of Driver complete does not hit the nail head in use, disassemble exhaust valve section to check malfunctions
as illustrated in Fig. 8.
Fig. 8
Exhaust valve is attached to four holes on Exhaust plate
when Driver complete moves to the lowest position.
Exhaust plate under Exhaust valve seals Cylinder
at the frame on Cylinder.
Exhaust plate
Exhaust valve
Exhaust valve
Punching metal
Exhaust plate
Exhaust plate
Exhaust cover M4x10 Hex socket
head bolt (2pcs.)
M4x10 Hex socket
head bolt (2pcs.)
Exhaust valve
Silencer
Silencer
Cylinder
Disassemble Exhaust cover, Silencer and Exhaust valve.
Silencer
frame on Cylinder
frame on Cylinder
frame on Cylinder
Exhaust plate
It causes the wrong driving like dry fire and the leakage of gas.
Note: It is possible that the tip of Driver complete does not hit the nail head in use because of the corrosion of adhesive
even if Exhaust valve and Exhaust plate do not look deformed/ damaged.
Scrape away the adhesive and apply fresh ThreeBond to treat such a case. (Refer to next page.)
Exhaust valve Deformed and damaged Exhaust valve / Exhaust plate
Normal condition of Exhaust valve and Exhaust plate
(1) Disassemble Handle set from Housing. (Fig. 2.)
(2) Remove Contact top, Arm plate and Front plate from Cylinder. And separate Cylinder section from Housing. (Fig.4)
(3) Disassemble Exhaust mechanism as illustrated in Figs. 9 and 10.
Fig. 9 Fig. 10

P 6/ 16
Repair
[3] DISASSEMBLY/ASSEMBLY
[3]-2. Exhaust valve section (cont.)
ASSEMBLING
Apply ThreeBond 1215 on the frame of
Cylinder as illustrated below.
applied portion of
ThreeBond 1215
Note: Wait until ThreeBond 1215 drys at least three hours, and then try nailing before actual work.
Incomplete drying causes the leakage of gas.
Set Punching metal
in place.
Attach Exhaust plate and tighten it with
M4x10 Hex socket head bolt (2pcs.)
so that the protrusions face Exhaust valve
installation side.
Punching
metal
Exhaust plate
protrusions of
Exhaust plate
Exhaust plate
M4x10 Hex socket
head bolt (2pcs.)
M4x10 Hex socket
head bolt (2pcs.)
Exhaust valve
Exhaust valve
Set Exhaust valve and Silencer in place. Tighten Exhaust cover with M4x10
Hex socket head bolt (2pcs.)
Silencer
Exhaust cover
Fig. 11
Fig. 12
Punching metal frame of Cylinder
(1) Use slotted screwdriver to scrape away adhesive left on the frame on Cylinder.
Note: The incomplete scraping causes the leakage of gas.
(2) Take the assembling step as illustrated in Figs. 11 and 12.
(3) Insert Cylinder section to Housing and assemble Front plate.
Assemble Contact top and Arm plate to the Driver guide section of Cylinder. Refer to Fig. 4.
(4) Assemble Handle set to Housing as illustrated in Fig. 2.

P 7/ 16
Repair
[3] DISASSEMBLY/ASSEMBLY
[3]-3. Chamber
DISASSEMBLING
(1) Disassemble Handle set from Housing as illustrated in Fig. 2.
(2) Remove Contact top, Arm plate and Front plate from Cylinder.
Separate Cylinder section from Housing as illustrated in Fig. 4.
(3) The removed Cylinder section can be disassembled as illustrated in Figs. 13 and 14.
1R268
Chamber
Chamber
Arm
Arm connector
While opening Arm’s ends,
pull Arm in the direction
designated with black arrow.
M4x16 Hex socket head bolt (4pcs.)
Remove Chamber top
and Chamber seal ring
from Chamber
Chamber top
Cylinder
Cylinder
Chamber
Pull Chamber carefully so that Compression
spring 8 does not spring out of Cylinder.
Remove these Spring pin3-32 (2pcs.) for joining Cylinder section
and Chamber.
Spring pin 3-32 (2pcs.)
Compression
spring 8 (2pcs.)
Stop
rubber (2pcs.)
Pay attention not to
strike Chamber.
Cylinder ring
Chamber seal ring
Arm
Note: Pay attention not to
lose Arm connector.
Fig. 13
Fig. 14

P 8/ 16
Repair
[3] DISASSEMBLY/ASSEMBLY
[3]-3. Chamber (cont.)
ASSEMBLING
Assemble Cylinder rings to Cylinder so that
the angle of the two notches is more than 90 degrees.
Cylinder ring (2pcs.)
(1) Assemble Cylinder rings to Cylinder as illustrated in Fig. 15.
Note: Apply the specific lubricants in accordance with the instruction shown in Fig. 1.
Cylinder
(2) Put Chamber seal ring on the edge of Chamber, and assemble Chamber top to Chamber by fastening with M4x16
Hex socket head bolt (4pcs.). Refer to the right illustration in Fig. 14.
(3) Setting Arm connector to Arm, assemble them to Cylinder. Refer to the left illustration in Fig. 14.
(4) Assemble Stop rubber and Compression spring 8 to Cylinder. Refer to the right illustration in Fig. 13.
(5) Applying Molybdenum disulphide lubricant to the outside of Cylinder (Fig. 1), insert it into Chamber.
Refer to right illustration in Fig. 13.
(6) Connect Cylinder with Chamber as illustrated in Fig. 16.
Fig. 15
Fig. 16
Spring Pin 3-32
Water pump pliers
Insert Spring pin 3-32 for approx. 5mm depth
with aligning two holes of Chamber with those of
Cylinder for Spring pin 3-32.
And then, set Spring pin 3-32 in place with water
pump pliers.
Insert the other Spring pin 3-32 in the same manner.
(7) Inserting Cylinder section into Housing, tighten Front plate with M5x16 Hex socket head bolt (3pcs.). Refer to Fig. 4.
(8) Assemble Contact top and Arm plate. Refer to Fig. 4.
(9) Assemble Handle set to Housing. Refer to Fig. 2.

P 9/ 16
Repair
[3] DISASSEMBLY/ASSEMBLY
[3]-4. Pusher, Handle section
DISASSEMBLING
M5x10 Hex socket head bolt
Fig. 17
Fig. 18
Note: Lock bar and Compression spring 4 easily fall off in this step.
Pay attention not to lose Lock bar and compression spring 4.
2. And then remove the following screws.
* M5x10 Hex socket head bolt
* 5x25 Tapping screw (3pcs.)
Handle set (L) and Nail feeding section
can be separated from Handle set (R).
Sliding Pusher lever toward the rear side,
insert Screwdriver to stop Pusher lever’s return.
Remove Lock bar and compression spring 4.
Lock Bar
Pusher lever
Compression spring 4
(1) Separate Handle set from Housing as illustrated in Fig. 2.
(2) Handle set (L) can be separated from Handle set (R) as illustrated in Fig. 17. And remove Lock bar
and Compression spring 4 as illustrated in Fig. 18.
Magazine support
Handle set (R)
Nail rail
Nail feeding section Handle set (L)
5x25 Tapping
screw (3pcs.)
Magazine
support
1. Pressing the end of Handle set,
remove Magazine support by
sliding it toward rear side.
Handle set (L)

P 10/ 16
Repair
[3] DISASSEMBLY/ASSEMBLY
[3]-4. Pusher, Handle Section (cont.)
DISASSEMBLING
(3) Pusher section can be disassembled from Handle set (L) as illustrated in Fig. 19.
(4) The other parts in Handle set can be disassembled as illustrated in Fig. 20.
M4x20
Pan head screw
Remove Pusher, Pusher holder Compression and spring 4
from Pusher lever by unscrewing M4x20 Pan head scerw.
Remove Spiral spring complete from
Drum portion of Pusher lever
Pusher
Handle set (L)
Spiral spring complete
Pusher holder
Lock claw of
Spiral spring
Pusher lever Pusher Lever
Compression
spring 3
Drum portion
Fig. 19
Fig. 20
Hook holder Hook
Lead wire cover
Spark unit
Switch Unit
Chamber Lock Bar
Line Filter
Battery case
Trigger