Hitachi 220-856 - Manual (Page 13)

307-830 13
Motor Brush Replacement
NOTE: Replace the brushes when they have worn to
less than 10 mm. See Fig. 12. Always replace both
brushes at the same time. A Brush Repair Kit, 220–853,
and spring clip, 110–816, are available.
NOTE: Replacement brushes may last only half as long
as the original ones. To maximum brush life, break in new
brushes by operating the sprayer with no load (remove
the pump connecting rod pin) for at least one hour.
01745C
Fig. 10
A
WARNING
INJECTION HAZARD
To reduce the risk of serious bodily
injury, follow the Pressure Relief Proce-
dure Warning on page 11 before check-
ing or repairing any part of the spray system.
1. Remove both inspection covers (A). See Fig. 10.
2. Push in the spring clip (E) to unhook it, and then
pull it out. See Fig. 11.
3. Loosen the terminal screw (F). Pull the brush lead
(E) away, leaving the motor lead (G) in place.
Remove the brush (C) and spring (B). See Fig. 12.
4. Inspect the commutator for excessive pitting,
burning or gouging. A black color on the commuta-
tor is normal. Have the commutator resurfaced by
a qualified motor repair shop if the brushes seem
to wear too fast.
5. Install the new brush (C) so its lead is in the long
slot (H) of the holder. See Fig. 13. Slide the termi-
nal (E) under the terminal screw washer. Make
sure the motor lead (G) is still connected the at the
screw. Tighten the screw (F). See Fig. 12.
6. Place the spring (B) on the brush as shown in Fig.
13. The spring must coil as shown.
7. Push in and hook the spring clip (D). See Fig. 13.
8. Repeat for the other side.
9. Test the brushes. Remove the connecting rod pin
(50). See 15, page 14. With the sprayer off, turn
the pressure control knob fully counterclockwise to
minimum pressure. Plug in the sprayer. Turn the
sprayer on. Slowly increase the pressure until the
motor is at full speed. Inspect the brush and
commutator contact area for excessive arcing.
Arcs should not “trail” or circle around the commu-
tator surface.
CAUTION
Do not touch the brushes, leads, springs or brush
holders while the sprayer is plugged in, to reduce the
risk of electric shock and serious bodily injury.
10. Install the brush inspection plates, gaskets and
covers.
11. Break in the brushes. Operate the sprayer for at
least one hour with no load. Then reinstall the
connecting rod pin (50).
Fig. 11
1
01227
B
C
D
Order part
no. 110–816
1
2 Hook of spring clip
2
Fig. 12
1
01227
B
C
D
E
F
G
10 mm minimum
1
Fig. 13
1
H
B
C
D
1
Spring
must
coil in this
direction