CAUTION:
• Pressing excessively on the tool will not speed up
the drilling. In fact, this excessive pressure will only
serve to damage the tip of your bit, decrease the
tool performance and shorten the service life of the
tool.
• Never use ‘‘rotation with hammering’’ when the drill
chuck assembly is installed on the tool. The drill
chuck assembly may be damaged.
Depth gauge (Fig. 18)
The depth gauge is convenient for drilling holes of
uniform depth. Loosen the clamp screw and adjust
the depth gauge to the desired depth. After adjusting,
tighten the clamp screw firmly.
NOTE:
The depth gauge cannot be used at the position
where the depth gauge strikes against the gear
housing/motor housing.
Indicator lamp (Fig. 19)
The green power-ON indicator lamp lights up when
the tool is switched ON. If the indicator lamp is lit but
the tool does not start, the carbon brushes may be
worn out, or the electric circuit or the motor may be
defective. If the indicator lamp does not light up and
the tool does not start, the ON/OFF switch or the
mains cord may be defective.
The red service indicator lamp lights up when the
carbon brushes are nearly worn out to indicate that
the tool needs servicing. After approx. 8 hours of use,
the motor will automatically be shut off.
MAINTENANCE
CAUTION:
Always be sure that the tool is switched off and
unplugged before carrying out any work on the tool.
Replacement of carbon brushes (Fig. 20 & 21)
Whenever carbon brushes must be replaced, they cut
out the tool automatically. When this occurs, remove
the screws which secure the brush holder cover.
Remove the brush holder cover and brush holder cap.
Then replace both carbon brushes at the same time.
Use only identical carbon brushes.
Lubrication
This tool requires no hourly or daily lubrication
because it has a grease-packed lubrication system.
Lubricate the tool every time the carbon brushes are
replaced.
Run the tool for several minutes to warm it up. Switch
off and unplug the tool.
Loosen the six screws and remove the handle. Note
that the top screws are different from other screws.
(Fig. 22)
Disconnect the connector by pulling it.
(Fig. 23)
Remove the crank cap using a hex wrench.
(Fig. 24)
Rest the tool on the table with the bit end pointing
upwards. This will allow the old grease to collect
inside the crank housing. Wipe out the old grease
inside and replace with a fresh grease (30 g). Use
only Makita genuine hammer grease (optional acces-
sory). Filling with more than specified amount of
grease (approx. 30 g) can cause faulty hammering
action or tool failure. Fill only with the specified
amount of grease. Reinstall the crank cap and tighten
with the hex wrench.
(Fig. 25)
Connect the connector and reinstall the handle.
(Fig. 26)
CAUTION:
• Be careful not to damage the terminals or lead wires
especially when wiping out the old grease or install-
ing the handle.
• Do not tighten the crank cap excessively. It is made
of resin and is subject to breakage.
To maintain product safety and reliability, repairs,
maintenance or adjustment should be carried out by a
Makita Authorized Service Center.
HR3550C (E) (’100. 8. 29)
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