Graco NOVA 390 PC - User Manual

Questions and Answers

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Brian SmithAug 15, 2025
What to do if fluid is spitting from my Graco Paint Sprayer gun?
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  Joseph ClarkAug 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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jason79Aug 17, 2025
Why is my Graco NOVA 390 PC pump difficult to prime?
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  Anthony ScottAug 17, 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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Daniel JonesAug 21, 2025
How to fix excessive paint leakage into the throat packing nut of my Graco NOVA 390 PC?
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  kempcassandraAug 21, 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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Nancy BairdAug 28, 2025
What to do if the motor runs but the pump doesn't stroke on my Graco NOVA 390 PC?
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  Kevin WashingtonAug 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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Michael HigginsAug 31, 2025
Why does my Graco Paint Sprayer stop after running for only 5 to 10 minutes?
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  williamsamyAug 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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cwarrenSep 3, 2025
What to do if my Graco NOVA 390 PC will not shut off after reaching maximum pressure?
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  Carol MccartySep 3, 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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Mary RossSep 7, 2025
Why does my Graco Paint Sprayer not run at all?
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  weaverjessicaSep 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.
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justin78Sep 10, 2025
How to troubleshoot basic electrical problems with my Graco Paint Sprayer?
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  Sydney RichmondSep 12, 2025
  For basic electrical problems with your Graco Paint Sprayer, ensure the motor leads are securely fastened and properly mated. Replace loose terminals and crimp them to the leads, ensuring they are firmly connected. Clean the circuit board terminals and securely reconnect the leads.
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Mckenzie BaldwinNov 23, 2025
Why is the pump output low on my Graco NOVA 390 PC?
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  Kathleen PattersonNov 23, 2025
  If your Graco Paint Sprayer's pump output is low, several factors could be the cause. First, the spray tip might be worn; in this case, relieve the pressure and replace the tip. A clogged spray tip is another possibility; relieve the pressure and clean the spray tip. Ensure that the paint supply is adequate by refilling and repriming the pump. Also, check for a clogged intake strainer, and if found, remove, clean, and reinstall it. If the intake valve ball and piston ball aren't seating properly, remove the intake valve and clean it, inspecting the balls and seats for damage. Additionally, a clogged fluid filter or tip filter can cause low output, so clean the filter. A leaking prime valve can also be the reason; relieve the pressure and repair the prime valve. Also, leaking around the thr...