Maintenance; Replacing Carbon Brushes - Makita BDF440 Instruction Manual

Drilling in wood
When drilling in wood, the best results are obtained with
wood drills equipped with a guide screw. The guide screw
makes drilling easier by pulling the bit into the workpiece.
Drilling in metal
To prevent the bit from slipping when starting a hole,
make an indentation with a center-punch and hammer at
the point to be drilled. Place the point of the bit in the
indentation and start drilling.
Use a cutting lubricant when drilling metals. The excep-
tions are iron and brass which should be drilled dry.
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 perfor-
mance and shorten the service life of the tool.
• There is a tremendous force exerted on the tool/bit at
the time of hole break through. Hold the tool firmly and
exert care when the bit begins to break through the
workpiece.
• A stuck bit can be removed simply by setting the
reversing switch to reverse rotation in order to back
out. However, the tool may back out abruptly if you do
not hold it firmly.
• Always secure small workpieces in a vise or similar
hold-down device.
• If the tool is operated continuously until the battery car-
tridge has discharged, allow the tool to rest for 15 min-
utes 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 attempting to perform
inspection or maintenance.

Replacing carbon brushes

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. (Fig. 10)
Use a screwdriver to remove two screws then remove the
rear cover. (Fig. 11)
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. (Fig. 12)
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.
(Fig. 13)
Make sure that the carbon brush caps have fit into the
holes in brush holders securely. (Fig. 14)
Reinstall the rear cover and tighten two screws securely.
To maintain product SAFETY and RELIABILITY, repairs,
any other maintenance or adjustment should be per-
formed by Makita Authorized Service Centers, always
using Makita replacement parts.
ACCESSORIES
CAUTION:
• These accessories or attachments are recommended
for use with your Makita tool specified in this manual.
The use of any other accessories or attachments might
present a risk of injury to persons. Only use accessory
or attachment for its stated purpose.
If you need any assistance for more details regarding
these accessories, ask your local Makita service center.
• Drill bits
• Screw bits
• Hook
• Various type of Makita genuine batteries and chargers
• Automatic refreshing adapter
• Plastic carrying case
7