Dewalt air nailer suddenly quit

[killahog]

I am in the middle of a project and my Dewalt Air nailer suddenly quit. The model is D51276 I am using the correct nails and have plenty of air pressure, no air leaks it just won’t trigger. Any suggestions?
Thanks

 

[Git]

See if the piston/striker is retracting all the way - if not, probably a problem with the rubber diaphragm or an O Ring somewhere

 

[KnurledNut]

Check the lock off switch behind the trigger. It should be centered. If its been bumped to the right, it wont fire.

 

[killahog]

Check the lock off switch behind the trigger. It should be centered. If its been bumped to the right, it wont fire.

Thanks, that is centered.

 

[killahog]

See if the piston/striker is retracting all the way - if not, probably a problem with the rubber diaphragm or an O Ring somewhere

I took the back off and the piston was toward the rear, I pushed it forward and put the back on , still nothing.

 

[killahog]

Is this ring supposed to have a gap in it?

 

[seber]

Dewalt uses a plastic ring at the rear. If it breaks you are done. It is the only part not available as replacement and the first thing to go.

 

[killahog]

Dewalt uses a plastic ring at the rear. If it breaks you are done. It is the only part not available as replacement and the first thing to go.

Wow if that ring breaks the tool is not repairable?

 

[KnurledNut]

Is this ring supposed to have a gap in it?

Yes. The piston ring is manufactured with the split so it can be installed. There is nothing wrong with it. And yes, they can be purchased, but yours appears to be fine.

 

[RTM]

If you can get exact dimensions on it, you may be able to replace it with a generic piece.
This guy may help

www.rebuild-kits.com - Kits + out of production parts

Kits + out of production parts

www.rebuild-kits.com

 

[RTM]

But on to questions : does it leak when you plug it in? Does it do anything when you pull the trigger? Is the trigger “set”, or is it sloppy like it won’t work, not energized (on my Senco, the trigger won’t set unless the safety is made to say the tip is in contact)

 

[KnurledNut]

Is the contact tip depressing when pushed?
When hooked to air, does the trigger pressurize?

 

[KnurledNut]

I took the back off and the piston was toward the rear, I pushed it forward and put the back on , still nothing.

The piston was in the correct position. I see no problem there.

 

[dogdog]

I would look at the triggers pistons... and including that safety ...

These things works like a quick exhaust valve, so if your main chamber have air and it is not striking the smaller quick exhaust valve might be plug or not working properly. You might have to take it out and clean the ports with some sort of wires the one they used to clean welding tips or something.

 

[killahog]

But on to questions : does it leak when you plug it in? Does it do anything when you pull the trigger? Is the trigger “set”, or is it sloppy like it won’t work, not energized (on my Senco, the trigger won’t set unless the safety to say the tip is in contact)

No leaks just a little hiss when I pull the trigger, The trigger does not feel like it has pressure behind it .

 

[RTM]

I would look at the triggers pistons... and including that safety ...

These things works like a quick exhaust valve, so if your main chamber have air and it is not striking the smaller quick exhaust valve might be plug or not working properly. You might have to take it out and clean the ports with some sort of wires the one they used to clean welding tips or something.

Yup, if no air on the trigger, the safety may not be working, or the trigger piston is shot. On mine, when the safety is depressed, it opens an air path from the big cylinder to th back of the trigger piston.

part 22 to 30/31 I think. This link says that part is very popular.

PartsWarehouse.com

DeWalt D51276K 15 Gauge 1" To 2 1/2" Finish Nailer (Type 1) Parts and Accessories. Largest Selection, Best Prices, Free Shipping Available at PartsWarehouse.com

www.partswarehouse.com

 

[KnurledNut]

Im going with a bad trigger valve.

 

[killahog]

Yup, if no air on the trigger, the safety may not be working, or the trigger piston is shot. On mine, when the safety is depressed, it opens an air path from the big cylinder to th back of the trigger piston.

part 22 to 30/31 I think. This link says that part is very popular.

PartsWarehouse.com

DeWalt D51276K 15 Gauge 1" To 2 1/2" Finish Nailer (Type 1) Parts and Accessories. Largest Selection, Best Prices, Free Shipping Available at PartsWarehouse.com

www.partswarehouse.com

Thank you for the link, I will order the trigger assembly and then take the gun apart. I noticed today the gun says max air pressure 120 and my compressor was set just little high at 125.

 

[Forgottonia]

Mine quit working a while back. The nail feeder was slightly gummed up. Now I just press downward on the nails a bit to make sure they feed in correctly. Worth a try...

 

[KnurledNut]

Thank you for the link, I will order the trigger assembly and then take the gun apart. I noticed today the gun says max air pressure 120 and my compressor was set just little high at 125.

Yikes. 90-95 should be plenty.

 

[killahog]

I searched you tube and found quite a few videos showing the original Orings were failing, so I will did into the trigger tomorrow .

 

[Kenstone1]

I run stuff somewhat "wet"/well lubed, never a problem...
might work for you
Worth a try...