Makita BTW074 Manuel D'instruction page 9

trouble on socket or bolt, etc.
If the tool is operated continuously until the battery
•
cartridge has discharged, allow the tool to rest for 15
minutes before proceeding with a fresh battery cartridge.
The fastening torque is affected by a wide variety of
factors including the following. After fastening, always
check the torque with a torque wrench.
1. When the battery cartridge is discharged almost
completely, voltage will drop and the fastening
torque will be reduced.
2. Socket
Failure to use the correct size socket will
•
cause a reduction in the fastening torque.
A worn socket (wear on the hex end or square
•
end) will cause a reduction in the fastening
torque.
3. Bolt
Even though the torque coefficient and the
•
class of bolt are the same, the proper
fastening torque will differ according to the
diameter of bolt.
Even though the diameters of bolts are the
•
same, the proper fastening torque will differ
according to the torque coefficient, the class
of bolt and the bolt length.
4. The use of the universal joint or the extension bar
somewhat reduces the fastening force of the
impact wrench. Compensate by fastening for a
longer period of time.
5. The manner of holding the tool or the material of
driving position to be fastened will affect the torque.
6. Operating the tool at low speed will cause a
reduction in the fastening torque.
MAINTENANCE
CAUTION:
Always be sure that the tool is switched off and the
•
battery cartridge is removed before attempting to
perform inspection or maintenance.
Never use gasoline, benzine, thinner, alcohol or
•
the like. Discoloration, deformation or cracks may
result.
Replacing carbon brushes
1
006258
1. Limit mark
9
Replace when they wear down to the limit mark. Keep
the carbon brushes clean and free to slip in the holders.
Both carbon brushes should be replaced at the same
time. Use only identical carbon brushes.
013585
Use a screwdriver to remove two screws then remove
the rear cover.
1
013586
Raise the arm part of the spring and then place it in the
recessed part of the housing with a slotted bit
screwdriver of slender shaft or the like.
013587
Use pliers to remove the carbon brush cap of the
carbon brushes. Take out the worn carbon brushes,
insert the new ones and replace the carbon brush cap in
reverse.
013588
Make sure to place the lead wire in opposite side of the
arm.
1. Rear cover
1
2. Screws
2
2 1. Spring
2. Recessed part
3. Arm
3
1. Carbon brush
cap
1