Troubleshooting a Leaky Spraygun Tip

There are several reasons why that gun might drool a little. December 10, 2007

I have a Kremlin pump with the MX gun. As I was spraying today, when I would stop, a little fluid would leak out of the tip of the gun, with little air bubbles forming in the excess liquid. Anyone know what's causing this? I sprayed for a little bit and it cleared up, but it was a nuisance while it was happening.

Forum Responses
(Finishing Forum)
From contributor T:
For the fluid leaking out of the tip, it sounds like you are ready to replace the seat. The seat is what the ball seats against to stop the flow of fluid when the trigger returns to the closed position. If the seat is clogged, dirty, or worn from abrasion of the fluid, it needs to be cleaned or replaced. The seat is in the nozzle of the gun and is removed with a flat head screwdriver. The part is inexpensive and designed as a wear part. You can get a seat in Delrin, stainless steel, or carbide. Select the appropriate seat for your product. It also sounds like you may need to replace the tip seal. That is the white o-ring behind the tip (or black with a screen on tips smaller than 06-XXX). This seal prevents the fluid from leaking out of the air passages of the air cap. If you are seeing fluid in those passages, replace this seal as well.

From contributor A:
Sounds like you had a minor clog in the tip or the ball needle that stopped it from seating properly. As you sprayed it worked itself loose, maybe. Taken the gun apart lately?

From the original questioner:
I'll take the gun apart to investigate. I didn't want to do it at the time because I was in the middle of spraying and didn't want to break everything down. Thank you.

From contributor M:
This has happened to me before. I was in such a rush that I didn't dry all the thinner off the screw tip. Then I saw it dripping just as I started spraying. Had to stop and clean it with thinner again and dry it better with air. Worked fine after. This has happened a few times.