Graco 390 User Manual (English)

Other manuals for Graco 390

Operation Manual40 pages

Repair Manual30 pages

Questions and Answers:

C
Christine GlennJul 30, 2025
What to do if my Graco Paint Sprayer motor won't operate?
- A
  aharrisJul 30, 2025
  If the Graco Paint Sprayer motor won’t operate, first, gradually increase the pressure setting to check if the motor initiates. If this doesn't work, the spray tip or fluid filter might be clogged. In that case, relieve the pressure and then clear the clog or clean the gun filter. If water or water-based paint has frozen in the sprayer, thaw it by placing the sprayer in a warm area until completely thawed before starting. If paint has hardened, consider replacing the pump packings. Also, check the displacement pump connecting rod pin, pushing it into place and securing it with the spring retainer. If the fan still doesn’t turn, the motor may need replacing.
A
Alex RamosAug 4, 2025
Why does my Graco Paint Sprayer motor run and pump strokes, but it's still not spraying?
- B
  Brad JenkinsAug 4, 2025
  If your Graco Paint Sprayer motor runs and the pump strokes, but it's not working correctly, ensure the prime valve is closed. Check the paint supply and refill and reprime the pump if necessary. Remove and clean the intake strainer, then reinstall it. Tighten the nut on the suction hose to prevent air leaks, and check the o-rings on the swivel. To ensure proper seating of the intake valve ball and piston ball, strain the paint before use to remove particles that could clog the pump. For leaks around the throat packing nut, which may indicate worn or damaged packings, or a damaged pump rod, consult the Pump Manual 309250.
P
perezanneAug 14, 2025
What to do if my Graco 390 motor runs but the pump doesn't stroke?
- D
  David MillerAug 14, 2025
  If the Graco Paint Sprayer motor runs but the pump doesn't stroke, check the displacement pump pin for damage or if it's missing; replace it if necessary, ensuring the retaining spring is fully in the groove around the connecting rod. Inspect the connecting rod assembly for any damage and replace it if needed. Also, examine the drive housing assembly and gears for damage, replacing them if necessary.
D
David MiddletonAug 19, 2025
Why is my Graco Paint Sprayer motor hot and running intermittently?
- C
  cmccoyAug 19, 2025
  If your Graco Paint Sprayer motor is hot and runs intermittently, first ensure the ambient temperature is not above 115°F (46°C) and the sprayer is not in direct sunlight; move it to a cooler, shaded area if necessary. If the motor has burned windings, indicated by burned commutator bars next to the positive brush, replace the motor. Also, check the tightness of the pump packing nut, loosening it and inspecting for leaks around the throat; replace the pump packings if needed.