Maintenance - Makita 6991D Betriebsanleitung

8. The proper fastening torque may differ depend-
ing upon the kind or size of the bolt. Check the
torque with a torque wrench.
SAVE THESE INSTRUCTIONS.
OPERATING INSTRUCTIONS
Installing or removing battery cartridge (Fig. 1)
• Always switch off the tool before insertion or removal of
the battery cartridge.
• To remove the battery cartridge, withdraw it from the
tool while pressing the push buttons on both sides of
the cartridge.
• To insert the battery cartridge, align the tongue on the
battery cartridge with the groove in the housing and slip
it into place. Always insert it all the way until it locks in
place with a little click. If not, it may accidentally fall out
of the tool, causing injury to you or someone around
you.
• Do not use force when inserting the battery cartridge. If
the cartridge does not slide in easily, it is not being
inserted correctly.
Selecting correct socket
Always use the correct size socket for bolts and nuts. An
incorrect size socket will result in inaccurate and incon-
sistent fastening torque and/or damage to the bolt or nut.
Installing or removing socket (Fig. 2 & 3)
CAUTION:
Always be sure that the tool is switched off and the bat-
tery cartridge is removed before installing or removing
the socket.
1. For socket without O-ring and pin
(Model 6991D & 6992D)
To install the socket, push it onto the anvil of the tool
until it locks into place.
To remove the socket, simply pull it off.
2. For socket with O-ring and pin (Model 6992D)
Move the O-ring out of the groove in the socket and
remove the pin from the socket. Fit the socket onto
the anvil of the tool so that the hole in the socket is
aligned with the hole in the anvil. Insert the pin
through the hole in the socket and anvil. Then return
the O-ring to the original position in the socket
groove to retain the pin. To remove the socket, fol-
low the installation procedures in reverse.
Switch action (Fig. 4)
CAUTION:
Before inserting the battery cartridge into the tool, always
check to see that the switch trigger actuates properly and
returns to the "OFF" position when released.
To start the tool, simply pull the trigger. Tool speed is
increased by increasing pressure on the trigger. Release
the trigger to stop.
Reversing switch action (Fig. 5)
CAUTION:
• Always check the direction of rotation before operation.
• Use the reversing switch only after the tool comes to a
complete stop. Changing the direction of rotation
before the tool stops may damage the tool.
• When not operating the tool, always set the reversing
switch lever to the neutral position.
This tool has a reversing switch to change the direction
of rotation. Depress the reversing switch lever from the A
side for clockwise rotation or from the B side for counter-
clockwise rotation. When the switch lever is in the neutral
position, the switch trigger cannot be pulled.
Operation (Fig. 6 & 7)
The proper fastening torque may differ depending upon
the kind or size of the bolt. The relation between fasten-
ing torque and fastening time is shown in the figures.
Hold the tool firmly and place the socket over the bolt or
nut. Turn the tool on and fasten for the proper fastening
time.
NOTE:
• Hold the tool pointed straight at the bolt or nut without
applying excessive pressure on the tool.
• Excessive fastening torque may damage the bolt or
nut. Before starting your job, always perform a test
operation to verify the adequate fastening speed and
time for your bolt or nut.
The fastening torque is affected by a wide variety of fac-
tors 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 the 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. Type of materials to be fastened, the manner of
holding the tool and the tool speed will affect the
torque.
CAUTION:
If the tool is operated continuously until the battery car-
tridge has discharged, allow the tool to rest for
15 minutes before proceeding with a fresh battery.

MAINTENANCE

CAUTION:
Always be sure that the tool is switched off and the bat-
tery cartridge is removed before carrying out any work on
the tool.
Replacement of carbon brushes (Fig. 8 & 9)
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, mainte-
nance or adjustment should be carried out by a Makita
Authorized Service Center.
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