Electric Motor Maintenance; Troubleshooting - Allpro 400E Operations Manual & Parts List

ELECTRIC MOTOR MAINTENANCE

1. LUBRICATION - This motor is supplied with prelubricated ball bearings, lubricated for life of bearing.
2. MOTOR BRUSHES need periodic inspection and replacement as wear indicates. Brush wear is greatly influ-
enced by individual application. It is recommended that brush wear be checked at early intervals of operation in
order to determine future required inspections. Standard Leeson brushes for this motor have an initial length of
3/4". When the brushes are worn to a length of 3/8", they should be replaced.
3. TO CHANGE THE BRUSHES, follow the procedures below:
a. Unplug the machine.
b. Open the two covers at the rear of the motor.
c. Loosen the screw holding the brush terminal and remove the brush lead.
d. Push the brush retainer clip in and remove.
e. Remove the worn brushes (one on each side of motor).
f. Install new brushes in reverse order and replace covers.
NOTE: For longer life, new brushes (Part No. 331-131) need to have a run in period. After changing brushes, set
up the machine for spraying. Use a bucket of water and Coro-chek mixture, a 50 foot x 1/4" airless hose, airless
gun with 0.017 tip on unit, turn the Prime/PR Control Valve to the Prime position and turn the unit on. Turn the
Pressure Control Knob to maximum pressure (fully CW position) and let the pump cycle at high speed in the prime
position for 20 minutes. This will allow the brushes to "run in" properly, giving a longer life.

TROUBLESHOOTING

PROBLEM
There is spitting from the gun.
Paint leaks into the wet cup.
The motor operates, but the
paint pump doesn't.
The motor and displacement
pump operates, but paint
pressure is too low or none.
CAUSE
The fluid supply is low or empty.
Air entrapped in the fluid pump or
hose.
The wet cup is loose.
The throat packings are worn or
damaged.
Piston Rod is Worn.
The pressure setting is too low.
The pump is seized by dried paint.
The pressure setting is too low.
The tip or gun filter is clogged.
Tip is worn.
The fluid displacement pump
filter is clogged.
There is a large pressure drop
in the fluid hose.
SOLUTION
Refill the supply container.
Check for loose connections on the
siphon assembly, tighten, then reprime
pump.
Tighten just enough to stop leakage.
Replace the packings. See page 21.
Replace Piston Rod.
Increase the pressure.
Service the pump. See pages 20 & 21.
Increase the pressure.
Remove the tip and/or filter and
clean them.
Replace Tip.
Clean the filter.
Use a larger diameter hose.
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