Graco 390 PC User Manual (English)

Questions and Answers:

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Heather AcostaAug 15, 2025
What to do if fluid is spitting from my Graco Paint Sprayer gun?
- A
  alexandrawrightAug 15, 2025
  If your Graco Paint Sprayer is spitting fluid, it could be due to a few reasons. There might be air in the pump or hose; check and tighten all fluid connections, and cycle the pump slowly during priming. Also, the spray tip could be partially clogged; clear the tip. Finally, the fluid supply might be low or empty; refill the fluid supply and prime the pump, checking the fluid supply often to prevent running the pump dry.
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Stephen MorganAug 18, 2025
Why is my Graco 390 PC Paint Sprayer pump difficult to prime?
- R
  Robert PerezAug 18, 2025
  If your Graco Paint Sprayer is difficult to prime, it could be due to several reasons. There might be air in the pump or hose. In this case, check and tighten all fluid connections and cycle the pump as slowly as possible during priming. Another cause might be a leaking intake valve. Clean the intake valve, ensuring the ball seat is not nicked or worn and that the ball seats well; then, reassemble the valve. Also, worn pump packings can cause priming issues; in this case, replace the pump packings. Finally, if the paint is too thick, thin it according to the supplier's recommendations.
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Gina WashingtonAug 22, 2025
How to fix excessive paint leakage into the throat packing nut of my Graco 390 PC?
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  Jesse MoranAug 22, 2025
  If your Graco Paint Sprayer experiences excessive paint leakage into the throat packing nut, it could be because the throat packing nut is loose. Remove the throat packing nut spacer and tighten the throat packing nut just enough to stop the leakage. Another possibility is that the throat packings are worn or damaged, in this case replace packings. In other case, the displacement rod is worn or damaged, in this case replace the rod.
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walterericaAug 28, 2025
What to do if the motor runs but the pump doesn't stroke on my Graco 390 PC?
- F
  Felicia HamiltonAug 28, 2025
  If your Graco Paint Sprayer motor runs but the pump does not stroke, it could be due to a damaged connecting rod assembly. In this case, replace the connecting rod assembly. Another possible cause is damaged gears or drive housing. Inspect the drive housing assembly and gears for damage and replace if necessary.
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Mary HunterAug 31, 2025
Why does my Graco 390 PC stop after running for only 5 to 10 minutes?
- E
  Edward WhitakerAug 31, 2025
  If your Graco Paint Sprayer operates for only 5 to 10 minutes and then stops, the pump packing nut might be too tight. When the pump packing nut is too tight, the packings on the pump rod restrict pump action and overload the motor. Loosen the pump packing nut and check for leaks around the throat. If necessary, replace the pump packings.
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Nicole CookSep 4, 2025
What to do if my Graco Paint Sprayer will not shut off after reaching maximum pressure?
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  Briana CrosbySep 4, 2025
  If your Graco Paint Sprayer will not shut off after reaching or exceeding maximum pressure, check the pressure control. Disconnect the pressure control; if the sprayer still runs, replace the control board. If the sprayer stops, replace the pressure control.
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Scott WilkersonSep 7, 2025
Why does my Graco 390 PC Paint Sprayer not run at all?
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  Matthew RodriguezSep 7, 2025
  If your Graco Paint Sprayer does not run at all, check the electrical supply, pressure control connections, pressure control, replaceable fuse, and motor leads. Ensure that there is AC voltage: 100-130V for 110-120VAC models or 210-255V for 230VAC models.

Graco 390 PC Specifications

General

Max Pressure	3300 PSI
Flow Rate	0.47 GPM
Motor Type	DC
Type	Airless Paint Sprayer
Power Source	Electric
Voltage	120 V
Hose Length	50 ft
Max Tip Size	0.021 in
Horsepower	0.625 HP
Weight	30 lbs