My Dewalt nail gun has air escaping from the nail exiting side, I just rebuild it with O-ring kit 5140122-77 with eReplacement Part but still has a leak?

SOURCE: Air leaks arond trigger when depressed, but no nail fires.

Where does the air leak out from? If it leaks from the trigger DeWalt makes a trigger valve assembly part # 641006-00 list 8.89 BUT if it leaks from other areas we have to look into it deeper. If it is just the trigger valve let me know and I will give you instructions how to remove and install the new one.

SOURCE: Dewalt 51488. Air leaks around trigger and won't fire nail.

Go to Dewaltservicenet.com and download a breakdown of the tool before starting. I would recoment changing all the O rings and make sure that you get a good grease to lube them first. Its not that hard.

SOURCE: carraige in dewalt nailer

just goto:
http://www.retrevo.com/search/v2/jsp/mytrevo/myTrevo.jsp?page=man

download the support manual. You should be on your way

SOURCE: nail gun wont fire

First - the air pressure has to be high enough - check the regulator on the tank to make sure it is delivering in excess of 60-70 psi (which I am sure you have already done).

If you have dry fired these guns (i.e. shot them off with no nails in them while you were lubricating them maybe) the mechanism inside could be damaged. I had that happen to one of my nailers (same brand). That was when I learned not to dry fire them...

Since both of them are not working though I would be more inclined to look at the air supply first.

SOURCE: my dewalt framing nail gun was hooked to the air

There are O-ring seals around the trigger that are probably leaking. You can try to lubricate the gun by adding the pneumatic oil to the air supply. That may be enough to seal it back up. Otherwise the seals and/or the trigger assembly will need to be replaced.

Dan