Maintenance And Inspection - Hitachi G 12VA Handling Instructions Manual

Wrench
Wheel nut
Depressed
center wheel
Wheel
washer
Wheel
guard
Spindle

MAINTENANCE AND INSPECTION

1. Inspecting the depressed center wheel
Ensure that the depressed center wheel is free of
cracks and surface defects.
2. Inspecting the mounting screws
Regularly inspect all mounting screws and ensure
that they are properly tightened. Should any of the
screws be loose, retighten them immediately. Failure
to do so could result in serious hazard.
3. Inspecting the carbon brushes (Fig. 5)
The Motor employs carbon brushes which are
consumable parts. When they become worn to or
near the "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 Numbers shown
in the figure. In addition, always keep carbon brushes
clean and ensure that they slide freely within the
brush holders.
6 mm
17 mm
Usual carbon brush
Auto-stop carbon brush
7
Diamond
wheel
Push button
Wear limit
No. of carbon brush
No. of carbon brush
88
76
Fig. 5
Radial grinding
wheel
Fig. 4
4. Replacing carbon brushes (Fig. 6)
<Disassembly>
(1) Loosen the D4 tapping screw retaining the tail cover
and remove the 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.
(3) Remove the end of the pig-tail on the carbon brush
from the terminal section of brush holder and then
remove the carbon brush from the brush holder.
<Assembly>
(1) Insert the end of the pig-tail of the carbon brush
in the terminal section of brush holder.
(2) Insert the carbon brush in the brush holder.
(3) Use the auxiliary hexagonal wrench or small
screwdriver to return the edge of the spring to the
head of the carbon brush.
NOTE
Make sure the end of the spring is not holding the
pig-tail.
(4) Mount the tail cover and tighten the D4 tapping
screw.
Washer nut
Sanding
disc
Rubber pad