25
307–786
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 differently 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 (56). 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
56
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
MOTOR 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.
