Hitachi DH 24DV - Manual (Page 23)

English
23
MAINTENANCE AND INSPECTION
CAUTION: Pull out battery before doing any inspection or maintenance.
1. Inspecting the drill bits
Since use of a dull tool will cause motor malfunctioning and degraded efficiency, replace
the drill bit with a new one or resharpening without delay when abrasion is noted.
2. Check the Mounting Screws
Loose mounting screws are dangerous. Regularly inspect them and make sure they
are tight.
CAUTION: Using this power tool with loosen screws is extremely dangerous.
3. Maintenance of the motor
The motor unit winding is the very “heart” of the power tool.
Exercise due care to ensure the winding does not become damaged and/or wet with oil
or water.
4. Inspecting the carbon brushes (Fig. 20)
The motor employs carbon brushes which are
consumable parts. When they become worn to or
near “wear limit”, it could result in motor trouble.
When an auto-stop carbon brush is equipped, the
motor will stop automatically. At that time, replace
both carbon brushes with new ones which have
the same carbon brush No. shown in the figure.
In addition, always keep carbon brushes clean and
ensure that they slide freely within the brush
holders.
5. Replacing the carbon brushes
(1) Loosen the screws (2) for the chuck cover, then
remove the chuck cover from the housing. (Fig.
21, Fig. 22)
(2) Pinch the terminals for the carbon brushes with
pliers, then pull them out of the brush holder. (Fig.
23)
(3) Pull the springs forward with a slotted screwdriver,
then remove the carbon brushes. (Fig. 24)
(4) Reverse these procedures to install the brushes.
Fig. 20
Fig. 23 Fig. 24
0.45"
(11.5 mm)
0.12" (3 mm)
Wear limit
Grip cover
Fig. 21
Screw
Fig. 22
Pull
Pull Terminal
Carbon brush
Pliers
Spring
Slotted
screwdriver
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