Makita 6917D Impact Driver User Manual


 
13
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 some-
what 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.
Replacing carbon brushes
Remove and check the carbon brushes regularly. 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 iden-
tical carbon brushes.
Use a screwdriver to remove the brush holder caps. Take out
the worn carbon brushes, insert the new ones and secure
the brush holder caps.
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 elec-
tric brake operation when releasing the switch trigger. If elec-
tric brake is not working well, ask your local Makita service
center for repair.
1. Limit mark
1
001145
1. Brush holder cap
2. Screwdriver
1
2
002376