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MAINTENANCE AND INSPECTION

WARNING: Be sure to turn off the switch and remove the battery before maintenance and inspection.

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.Inspecting the screws

Regularly inspect all screws and ensure that they are fully tightened. Should any of the screws be loosened, retighten them immediately.

WARNING: Using this drill with loosened 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. 15)

The motor employs carbon brushes which are consumable parts. Since and excessively worn carbon brush can result in motor trouble, replace the carbon brush with new ones when it becomes worn to or near the “wear limit”. In addition, always keep carbon brushes clean and ensure that they slide freely within the brush holders.

NOTE:

Wear limit

0.12" (3 mm)

0.45"

(11.5 mm)

Fig. 15

When replacing the carbon brush with a new one, be sure to use the Hitachi Carbon Brush Code No. 999058.

5.Replacing carbon brushes

Take out the carbon brush by first removing the brush cap and then hooking the protrusion of the carbon brush with a slotted-head screw driver, etc., as shown in Fig. 16, Fig. 17.

When installing the carbon brush, choose the direction so that the nail of the carbon brush (Fig. 16) agrees with the contact portion outside the brush tube (Fig. 18). Then push it in with a finger.

Lastly, install the brush cap.

Nail of carbon brush

Protrusion of carbon brush

Fig. 16

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Hitachi DV 24DV instruction manual Maintenance and Inspection