Graco 390 253958, Important Safety Instructions Manual

Page: 10 / 32

Troubleshooting
10 311737B
Troubleshooting
Problem
What To Check
(If check is OK, go to next check)
What To Do
(When check is not OK, refer to this column)
Motor Won’t Operate
Basic Fluid Pressure 1. Pressure control knob setting.
Motor will not run if set at mini-
mum (fully counter-clockwise). Slowly increase pressure setting to see if motor
starts.
2. Spray tip or fluid filter may be
clogged. Relieve pressure , page 8. Then clear clog or
clean gun filter. Refer to gun instruction manual,
309639.
Basic Mechanical 1. Pump frozen or hardened paint Thaw sprayer if water or water-based paint has
frozen in sprayer. Place sprayer in warm area to
thaw. Do not start sprayer until thawed com-
pletely. If paint hardened (dried) in sprayer,
replace pump packings. See page 14,
Dis-
placement Pump Replacement .
2. Displacement pump connecting
rod pin. Pin must be completely
pushed into connecting rod and
retaining spring must be firmly in
groove or pump pin. Push pin into place and secure with spring
retainer. See page 14,
Displacement Pump
Replacement .
3. Motor. Remove drive housing
assembly. See page 16,
Drive
Housing Replacement . Try to
rotate fan by hand.
Replace motor if fan won’t turn. See page 27,
Motor Replacement .