# Spray gun keeps spraying after trigger is released- how to fix?



## markcool (May 25, 2012)

I have just started working with an airless paint sprayer. It seems I've spent as much time tinkering with it and cleaning it as I have actually applying paint with it.

My latest issue is that the sprayer continues going after the trigger is released, and I can stop it unless I turn it off.

Is there dirt or grit somewhere in the gun itself? Or is it in the intake or output valves? I have taken the gun apart completely and cleaned it and all filters, but the problem re-occurs. 

Any tips or suggestions? 

Thank you,

Mark


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## robladd (Nov 22, 2010)

When you release the trigger is it still wide open spraying or is it partially spraying?


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## Paradigmzz (May 5, 2010)

What kind of gun? If you don't know post a pic.


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## jack pauhl (Nov 10, 2008)

This gun will continue to spray if not lubed. The spray pattern typically turns off slow after releasing the trigger when it needs oiled. I believe this happens after leaving a gun submerged in water too many times.


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## Oden (Feb 8, 2012)

jack pauhl said:


> This gun will continue to spray if not lubed. The spray pattern typically turns off slow after releasing the trigger when it needs oiled. I believe this happens after leaving a gun submerged in water too many times.


Break it down and soak it in thinners. A shot of WD sometimes will do the trick.
that is what I'd try first anyway.


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## PhillysFinest (Jun 9, 2012)

The parts should always be lubricated after cleaning with water.


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## ibsocal (Apr 17, 2007)

Adjust the lock nut at the top back end of the gun,loosen it.or get a rebuild valve kit it may be worn out.


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## Eurosportgti (Jun 17, 2012)

ibsocal said:


> Adjust the lock nut at the top back end of the gun,loosen it.or get a rebuild valve kit it may be worn out.


Agreed. Same thing just happened to me and the push rod had bent. No idea how but it did....Rebuild Kit ordered, Paid 50 some bucks for it, Rebuilt it it in a half hour one night and it worked like new the next day!


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## Paradigmzz (May 5, 2010)

PhillysFinest said:


> The parts should always be lubricated after cleaning with water.


I'll get right on that...


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## mr.fixit (Aug 16, 2009)

more often than not when that happens you need to rebuild the gun. It is a Graco gun and the repair kit number is 218-070 list price $90.50


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## caddisfly007 (Mar 25, 2009)

It's not lube or debris that is causing your gun to continue spraying after trigger is released it is the mechanics of the gun. Inside the gun is a long "stem/needle" with a stainless ball (halfball) attached to the one end. That ball gets pushed up tight to the diffuser (threaded front which recieves the guard) which holds a carbide seat. As the gun gets used over and over again the stainless ball (halfball) starts to wear out causing a small ring to appear where it depresses up onto the carbide seat. Over time this ring gets deeper and deeper until it can't hold pressure. Slowly you will get a gun leak which will cause spitting. Eventually it gets so bad that the gun does not shut off and continues to spray. You can buy a repair kit at any Sherwin store and put it in your self. It is very easy and will only take about 10-15 minutes. Here is a pointer: remember that when you adjust the back screw on the gun DO NOT tighten it all the way. You want a little play in your trigger. The way you might want to adjust the gun is by firing up the sprayer then while the screw is faily loose slowly twist it until the gun shuts off. I have repaired many guns over my carreer. Hope this helps.


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## mudbone (Dec 26, 2011)

markcool said:


> I have just started working with an airless paint sprayer. It seems I've spent as much time tinkering with it and cleaning it as I have actually applying paint with it.
> 
> My latest issue is that the sprayer continues going after the trigger is released, and I can stop it unless I turn it off.
> 
> ...


 That's not cool Mark!:whistling2:


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