820-204
21
Motor Brushes
NOTE: Replace brushes when worn to about 12.5 mm
(0.5 in.) . Always check both brushes. Brush Repair Kit
236–967 is available for motors manufactured by
Pacific Scientific. Consult Rev. A of this manual for
repair kit and instructions if your unit has a Leeson
motor.
NOTE: Replacement brushes may last only half as
long as the original ones. To maximize brush life, break
in new brushes by operating the sprayer with no load
as instructed in this procedure.
To reduce the risk of serious injury, follow the Pres-
sure Relief Procedure in your sprayer instruction
manual before doing this procedure. Unplug the
sprayer!
1.
Remove both inspection covers (A) and their gas-
kets. See Fig.14.
03199A
Fig. 14
A
2.
Push in the spring clip (F) and release its hooks
(G) from the brush holder (B). Pull out the spring
clip. See Fig. 15.
3.
Inspect the commutator for excessive pitting, burn-
ing or gouging. A black color on the commutator is
normal. Have the commutator resurfaced by a quali-
fied motor repair shop if the brushes seem to wear
too fast or arc excessively. See Step 8.d., also.
4.
Repeat for the other side.
5.
Place a new brush (C) in the holder (B) so the
ramp (H) faces the spring. See Fig. 15.
6.
Holding the spring clip (F) at a slight angle, slide
the spring clip into the brush holder and hook it
over the end of the holder. See Fig. 16. Pull on the
spring clip to be sure it stays in place. Connect the
brush lead to the blade connector (E).
7.
Repeat for the other side.
8.
Test the brushes.
a.
Remove the pump connecting rod pin (17).
b.
With the sprayer OFF, turn the pressure con-
trol knob fully counterclockwise to minimum
pressure. Plug in the sprayer.
c.
Turn the sprayer ON. Slowly increase the
pressure until the motor is at full speed.
d.
Inspect the brush and commutator contact area
for excessive arcing. Arcs should not trail or cir-
cle around the commutator surface.
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.
9.
Install the brush inspection covers and gaskets.
10. Break in the brushes. Operate the sprayer for at
least one hour with no load. Install the pump
connecting rod pin.
Fig. 15
F
G
E
D
C
B
H
1
1
Motor lead; do not disconnect
2
Minimum 12.5 mm (.5 in.)
2
03881
Fig. 16
1
G
C
E
F
