I have DeWalt framing nailer model D51844 SN:2113 Type 5 and when i hook my air hose to the gun and try to fire a nail, the gun just makes a small popping sound with a burst of air that blows out around the trigger, and no nail comes out. I took the back cover off and was looking for something obvious and found two O-Rings that have seen there better day. One O-Ring was broke in half and the other one was really gummy and coming apart. Could these two O-Rings be my problem or is it something else?
Yes, your damaged o-rings are most likely the problem and at this point it's best to just throw an o-ring kit in the gun instead of replacing the two damaged o-rings; you don't know in what condition the rest of them are in.
The second photo is most telling, that o-ring in the Head Valve is probably the main cause of the lack of firing/leaking/popping from the trigger. It's letting air escape past that o-ring so you're not getting suction to bring the driver back up to position.
Attached is as .pdf doc that has some trouble shooting tips, figured this couldn't hurt.
I hope this helps!
P.S. Keep the gun lubed with pneumatic nailer oil during every use, obviously, but also lube it before you put it away (a couple drops). This will keep the o-rings and seals lubricated so they don't dry-rot, especially if you're in a dry climate.
