Makita AN942 Manual

This model was developed as the more durable for
2 x 4 construction method.
Operating air pressure 0.44-0.83MPa ( 4.5 to 8.5 kgf/cm2G 65-120 PSIG)
Nail size 4.1mm in diameter and 90 mm in length
Nail capacities
Net Weight(kg)
Oiler (containing #90 turbine oil: 30cc)
Nose adaptor
Safety goggles
Specifications
Standard equipment
Optional accessories
CONCEPTION AND MAIN APPLICATIONS
Models No.
Product
TECHNICAL INFORMATION
Description
376mm (14-3/4")
446mm (17-1/2")
108mm (4-1/4")
AN942
Makita Pneumatic construction nailer
The standard equipment for the tools shown may differ from country to country.
2.9mm in diameter and 50 mm in length
(0.113" in diameter and 2" in length)
60 - 84 nails
3.8 kg (8.4lbs)
(0.131" in diameter and 3/1/2" in length)
P 1 / 7

Repair
< 1 > General instruction.
< 2 > Disassembling head bulb section.
< 3> Assembling the head bulb section.
< 4 > Disassembling trigger section.
< 5 > Assembling magazine section.
< 6 > Attaching of driver complete.
< 7 > Repair to stop the leaking air.
Please refer to the following matters on the repair.
< 1> General instruction
I. O rings and O ring part which contacts the sliding parts, have to be coated
with turbine oil (standard equipment), or grease (Isolex NB52), when the machine is
mounted.
II. Please refer to the following parts name.
Exhaust cover
Top cap
Housing
Driver guide
Contact arm Pusher lever
Magazine
Joint
Inlet cap
Trigger
III. The bolts have to be fastened as follows.
Bolt and Bolt size Fastening section Fastening torque
Hex socket head bolt M6 x 25
Hex socket head bolt M5 x 30
Hex socket head bolt M8 x 25
Housing - Top cap
Housing - Inlet cap
Housing - Driver guide
9 - 13 Nm
(90 - 130 Kgf.cm)
5 - 7 Nm
(50 - 75 Kgf.cm)
20 - 30 Nm
(200 - 300 Kgf.cm)
IV. Confirm the following matters after mounting of the parts.
* Pusher can slide smoothly.
* Contact arm and trigger can move smoothly.
* Singly by pressing the trigger or contact arm, the machine does not start.
P 2 / 7

Repair P 3 / 7
< 2 > Disassembling head bulb section.
( 1 ) Unscrew 4 pcs. of hex socket head bolts M6x25 and separate top cap and top cap gasket from housing. See Fig. 1
( 2 ) Unscrew 3 pcs. of hex socket head bolts M5x10 and separate exhaust cover from top cap. See Fig. 1.
( 3 ) Strike the thin bar inserted in to the hole of top cap, then the following parts can be removed from top cap
as illustrated in Fig. 2.
* Head valve with valve seat, O ring 40 and O ring 56
* Cushion R with washer 34
* Compression spring 5
* Driver complete with O ring 49
( 4 ) Remove valve seat from head valve. See Fig. 3.
Fig. 1
Hex socket head
bolts M6x25 ( 4 pcs.)
Hex socket head
bolts M5x10 ( 3 pcs.)
Top cap
Top cap
Exhaust cover
Fig. 2
Head valve with
valve seat,
O ring 40 and
O ring 56
Compression
spring 5
Cushion R
with washer 34
Top cap gasket
For removing, lever up valve seat
with flat head screwdriver.
Head valve
Valve seat
Fig. 3
Fig. 4
Fig. 5
< 3 > Assembling the head bulb section.
( 1 ) Put washer 34 and cushion R into head valve. See Fig. 4.
( 2 ) Mount compression spring 50 and head valve section
to top cap. See Fig. 5.
Head valve Cushion R
Washer 34 Top cap
Compression
spring 50
Head valve section
assembled in Fig.4
(It has to be pushed into
head cap until the boss of cushion R
is engaged firmly with head cap.)
Boss of
cushion R

Repair P 4 / 7
< 4 > Disassembling the trigger section.
< 5 > Assembling the magazine section.
( 1 ) Remove spring pin 3-28 of No.1 and then, the same of No.2. See Fig. 6.
( 2 ) Remove the following parts from housing. See Fig. 6.
* Trigger valve case
* Trigger valve stem
* Compression spring 3
* Pilot valve
( 3 ) Unscrew 4 pcs. of hex socket head bolts M6x25 and separate top cap and top cap gasket from housing.
And then, remove trigger valve guide as illustrated in Fig. 7.
No.1 Spring
pin 3-28
No.2 Spring
pins 3-28
Trigger
Fig. 6 Fig. 7
Fig. 8
Trigger valve case
Trigger valve stem
Compression spring 3
Pilot valve
Hex socket head
bolts M6x25
Top cap
Trigger valve guide
Thin bar
Top cap
gasket
Pusher lever Magazine
( 1 ) Mount pusher lever to magazine. Push pusher lever in the direction shown with the black arrow,
and insert a bar into the hole of magazine to hold the pusher lever for easy assemble of
the magazine section. See Fig. 8.
a Bar

Repair P 5 / 7
( 2 ) Mount contact arm to driver guide. And the, mount magazine to housing. See Fig. 9.n
( 3 ) The hex socket head bolt for joint has to be fastened loosely at the first. Finally it has to be
tightened firmly.
Fig. 9
Fig. 10
Contact arm
Driver guide
Magazine section
< 6 > Mounting driver complete
Pass driver complete through driver guide with aligning. See Fig. 10.
Driver guide
Hole's figure
of driver guide Figure of
driver complete's rod
Driver complete

Fig. 12
Repair P 6 / 7
< 7 > Repair to stop the leaking air.
If the air leaks out from the portion shown in Fig. 11, when you connect the product with an air compressor, check or
replace the joint portion and sealing material ( O rings, gaskets etc.).
A
B
C
D
E
Fig. 11
Fig. 15
Fig. 16
Fig. 17
Fig. 18
Fig. 19
Fig. 20
A) Leaking from the exhaust
Check or replace the following parts.
See Fig. 12
* Valve seat
* O ring 40
C) Leaking from the trigger section
Check or replace the following parts.
See Fig. 14
* O ring 3 * O ring 12
* O ring 8 * O ring 18
D) Leaking from the joint of inlet cap and housing
Check or replace the following parts.
See Fig. 15
* Inlet cap gasket
* Hex socket head bolt M5x30
B) Leaking from the joint of housing and top cap
Check or replace the following parts.
See Fig. 13
* Top cap gasket
* Hex socket head bolt M6x25
Valve seat
O ring 40 Top cap
gasket
Hex socket
head bolts M6x25
(Fasten it firmly
if it is loose.)
Fig. 13
Fig. 14
O ring 3
O ring 12
O ring 8
O ring 18 Hex socket
head bolts M5x30
(Fasten it firmly
if it is loose.)
Inlet cap gasket

Repair P 7 / 7
A
B
C
D
E
Fig. 11
Fig. 16
O ring 87
O ring 60
E) Leaking from the top of driver guide
See Fig. 16
* O ring 87 on cylinder separator
* O ring 60 on cylinder
Cylinder separator
Cylinder