Replacing Carbon Brushes - Makita BTW250 Manuel D'instruction

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
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.
Use a screwdriver to remove two screws then remove
the rear cover.
1. Limit mark
7
007458
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.
1
007459
Use pliers to remove the carbon brush caps of the carbon
brushes. Take out the worn carbon brushes, insert the
new ones and replace the carbon brush caps in reverse.
007460
Make sure that the carbon brush caps have fit into the
holes in brush holders securely.
1
2
006304
Reinstall the rear cover and tighten two screws securely.
After replacing brushes, insert the battery cartridge into
the tool and break in brushes by running tool with no load
for about 1 minute. Then check the tool while running and
electric brake operation when releasing the switch trigger.
If electric brake is not working well, ask your local Makita
service center for repair.
1. Rear cover
1
2. Screws
2
1. Spring
2. Arm
3. Recessed part
3
2
1. Carbon brush
cap
1
1. Hole
2. Carbon brush
cap