Maintenance - Makita 6905B Instruction Manual

Operation
The proper tightening torque may differ depending upon the kind or size of the bolt. The relation between
tightening torque and tightening time is shown in the figure below.
Hold the machine firmly and place the socket over the bolt or nut. Turn the machine on and tighten for the proper
tightening time.
NOTE:
• Hold the machine pointed straight at the bolt or nut without applying excessive pressure on the machine.
• Excessive tightening torque may damage the bolt or nut.
The tightening torque is affected by a wide variety of
factors including the following.
After tightening, always check the torque with a
torque wrench.
1. Socket
• Failure to use the correct size socket will cause
a reduction in the tightening torque.
• A worn socket (wear on the hex end or square
end) will cause a reduction in the tightening
torque.
2. Bolt
• Even though the torque coefficient and the class
of bolt are the same, the proper tightening
torque will differ according to the diameter of
bolt.
• Even though the diameters of bolts are the
same, the proper tightening torque will differ
according to the torque coefficient, the class of
bolt and the bolt length.
3. The use of the universal joint or the extension bar
somewhat reduces the tightening force of the
impact wrench. Compensate by tightening for a
longer period of time.
4. The manner of holding the machine will affect the
torque.
4
Tightening time
Rated voltage
90% of rated voltage

MAINTENANCE

CAUTION:
Always be sure that the machine is switched off and
unplugged before carrying out any work on the
machine.
Replacement of carbon brushes (Fig. 4 & 5)
Replace carbon brushes when they are worn down to
the limit mark. Both identical carbon brushes should
be replaced at the same time.
To maintain product safety and reliability, repairs,
maintenance or adjustment should be carried out by
Makita Authorized Service Center.
For 6906
For 6905B
seconds