Hitachi WH9DM2, WR9DM2, WR12DM2, WH12DM2 instruction manual Maintenance and Inspection

English

MAINTENANCE AND INSPECTION

CAUTION: Pull out battery before doing any inspection or maintenance.

1.Checking the condition of the bit (WH12DM2, WH9DM2)

The bits should be checked regularly. If worn or broken bits can slip or decrease the efficiency of the motor and burn it out.

Replace worn bits with new ones.

CAUTION: If you use a driver bit of which point is worn or broken, it will be dangerous since it slips. So replace it with a new one.

2.Checking the condition of the socket (WR12DM2, WR9DM2)

A worn or deformed hex. or a square-holed socket will not give an adequate tightness to the fitting between the nut or anvil, consequently resulting in loss of tightening torque. Pay attention to wear of a socket holes periodically, and replace with a new one if needed.

3.Check the Screws

Loose screws are dangerous. Regularly inspect them and make sure they are tight.

CAUTION: Using this power tool with loosened screws is extremely dangerous.

4.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.

5.Inspecting the carbon brushes (Fig. 24)

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: When replacing the carbon brush with a new one, be sure to use the Hitachi Carbon Brush Code No. 999054.

6.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 flat head screw driver, etc., as shown in Fig. 26.

When installing the carbon brush, choose the direction so that the nail of the carbon brush agrees with the contact portion outside the brush tube. Then push it in with a finger as illustrated in Fig. 27. Lastly, install the brush cap.

Wear limit

0.12" (3mm)

0.45"

(11.5mm)

Fig. 24

Nail of carbon brush

Protrusion of carbon brush

Fig. 25

Fig. 26

27