25
307–785
MOTOR
BRUSH
REPLACEMENT
NOTE: Replace the brushes when they have worn to
less
than 1/2 in. Refer to STEP 1, Fig 25–3. Note
that
the
brushes wear dif
ferently on each side of
the
motor
,
so check them both. Brush Repair Kit
220–853
is available.
Before doing this procedure, follow the Pressure
Relief Procedure Warning on page 24 to reduce
the risk of a fluid injection injury , splashing in the
eyes or on the skin, injury from moving parts, or
electric shock.
Unplug the sprayer!
WARNING
1. Remove
the motor shield (59). Remove the inspec
-
tion covers (J) and gaskets (K) on each side of the
motor.
Refer to Fig 25–1.
Fig 25–1
J
F
59
2. Push in the spring clip to release its hooks from the
brush holder. Pull out the spring clip. Refer to Fig
25–2.
3.
Loosen
the brush lead terminal screw
. Pull the brush
lead
away
, but leave the motor lead terminal in
place.
Remove
and discard the brush and spring. Refer to
Fig 25–3.
4. Inspect the commutator for excessive pitting, burn-
ing
or gouging.
NOTE: A
black color on the commutator is normal. Have
the
commutator resurfaced by a qualified
motor
repair
shop if the brushes seem to wear too
fast.
5. Repeat
for the other side.
CAUTION
When installing the brushes, follow all steps care-
fully. Improper installation damages parts beyond
use.
6. Place
a new brush in the holder so the lead is in
the
long slot of the holder. Slide the terminal under the
terminal
screw washer
. Ensure the motor lead is still
connected
at the screw
. Refer to Fig 25–4.
7. Place
the spring on the brush as shown in Fig 25–4.
Do
not install backwards
to avoid damage when the
spring
clip is installed.
8. Install
the
spring clip and push it down until its hooks
catch the short slots in the housing. Refer to Fig
25–4.
Incorrect installation may jam the clip.
9.
Repeat for the other side.
BRUSH
Fig 25–2
SPRING
BRUSH
LEAD
TERMINAL SCREW
MOT
OR LEAD
TERMINAL
SPRING CLIP
HOOK
Fig
25–4
BRUSH
SHORT
SLOT
LONG SLOT
BRUSH HOLDER
NOTE: SPRING MUST COIL
IN THIS DIRECTION
Fig
25–3
SPRING
CLIP
BRUSH
SPRING
CLIP
SPRING
10. Test the brushes.
a. With the sprayer OFF, turn the pressure control
knob fully counterclockwise to minimum pres-
sure.
Plug in the sprayer
.
b. Turn the sprayer ON. Slowly increase the pres-
sure
until the motor comes up to full speed.
c. 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
.
WARNING
CAUTION
Do not run the sprayer dry for more than 30 sec-
onds while checking the brushes to avoid damag-
ing the displacement pump packings.
11. Install the brush inspection covers and gaskets. In-
stall
the motor shield.
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