Graco GMAX II 3900 User Manual (English)

Other manuals for Graco GMAX II 3900

Questions and Answers:

J
James DuranJul 30, 2025
Why won't my Graco GMAX II 3900 engine start?
- J
  Jenna BarnesJul 30, 2025
  The engine of your Graco Paint Sprayer might not start due to several reasons. Here's what to check: * Ensure the engine switch is turned ON. * Refill the gas tank if it's empty. * Check and replenish the oil level if it's low. * Make sure the spark plug cable is connected and the spark plug isn't damaged; replace if necessary. * If the engine is cold, use the choke. * Confirm the fuel shutoff lever is in the ON position. * If oil has seeped into the combustion chamber, remove the spark plug, pull the starter 3-4 times, clean or replace the spark plug, and keep the sprayer upright.
D
Danielle AndrewsAug 10, 2025
What to do if my Graco Paint Sprayer engine runs but the pump doesn't?
- N
  Nicole AdamsAug 10, 2025
  If your Graco Paint Sprayer's engine is running but the displacement pump isn't operating, consider the following: * Ensure the pump switch is turned ON. * Increase the pressure by turning the pressure adjusting knob clockwise. * Check if the displacement pump piston rod is stuck due to dried paint. * Check that electrical power is energizing clutch field. With pump switch ON and pressure turned to MAXIMUM, use a test light to check for power between clutch test points on control board. Remove clutch wires from control board and measure resistance across clutch coil. At 70° F, the resistance must be between 1.2 +0.2?; if not, replace pinion housing. Also, remember to have your pressure control checked by an authorized Graco dealer.
J
Jennifer JohnsonAug 19, 2025
What to do if the WatchDog system on my Graco GMAX II 3900 Paint Sprayer is tripping falsely?
- B
  Brad TurnerAug 19, 2025
  If the WatchDog system on your Graco Paint Sprayer is tripping falsely, displaying 'EMPTY' and preventing the pump from running, it could be due to operating conditions being outside of the WatchDog parameters or low pump output. Try turning the pressure down. You can also operate without the WatchDog active.