Hitachi G 12S2 - Manual (Page 14)

English
14
MAINTENANCE AND INSPECTION
WARNING: ⅷ Be sure to switch power OFF and disconnect the plug from the
receptacle during maintenance and inspection.
ⅷ Using cracked, deformed or damaged wheels can lead to wheel
breakage and resulting serious injury.
1. Replacing the depressed center wheel
Replace the depressed center wheel when it has been worn out to about 2-3/8" (60mm)
in external diameter. Confirm that there is no crack or any damage to the depressed
center wheel. If there is a crack or a transformation in the wheel, replace it immediately.
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 grinder with loosened screws is extremely dangerous.
3. Confirm that there is no damage in the
wheel guard, the electrical cord and the
housing, etc.
Check that the on/off switch operates
normally.
4. Inspecting the carbon brushes (Fig. 6)
The motor employs carbon brushes which
are consumable parts. Replace the carbon
brush with a new one when it becomes worn
to its wear limit. Always keep carbon
brushes clean and ensure that they slide
freely within the brush holders.
CAUTION: Using this grinder with a carbon brush which is worn in excess of the wear
limit will damage the motor.
NOTE: Use HITACHI carbon brush No. 88
indicated in Fig. 6.
⅜ Replacing carbon brushes (Fig. 7):
<Disassembly>
(1) Loosen the D4 tapping screw retaining
the tail cover and remove tha tail cover.
(2) Use the auxiliary hexagonal wrench or
small screwdriver to pull up the edge of
the spring that is holding down the
carbon brush. Remove the edge of the
spring toward the outside of the brush
holder.
Fig. 6
Wear limit
0.24" (6mm)
0.67" (17mm)
No. of carbon
brush
88
Fig. 7
Carbon Brush Brush Holder
Spring