I did a complete rebuild on my framing nail gun it fixed the air leaks but now it won't even fire

Again sounds like blown O ring give it a squirt of 3in1 oil and fire it several times (if oil is compatible in your gun). Repair center if that doesn't work. Trash can also get in the air orifice and stop moving parts from moving.

Remove the nails and take off the trigger to expose the trigger valve (usually part # tva6). Connect air and spray soapy water on the valve to determine if the air is leaking from the center of the valve or around the outer edge between the body and valve. If leaking from the center, could be defective valve or debris under oring. Pop out the valve and examine internal parts for cut oring or defect. If leaking from between body, you could have cut orings installing the valve. Make sure that there are no rough edges in the body of the gun. Bump fire or single fire happens with the trigger type not the valve. Bump fire trigger is usually black metal and single fire trigger is light color plastic. Good luck

n80 coil nailer is a very powerful nailer used for hard wood. If the driver is setting nails too deep, adjust safety foot to the lowest level. Install safety foot no-mar boot to lift the gun even higher. If still too deep, most likely the lower bumper inside the gun is worn-out or cracked. Easy test. Remove nails and connect air supply. With trigger depressed, push and hold the gun against work (I use an old rubber hose tightly coiled up). This will fire the gun but keep the driver down allowing you to examine the tip of the driver. The driver should extend out past the nose less than quarter inch. If the driver is extending too far, most likely bumper is worn out. If a large quantity of air is leaking out the nose of gun during the test, indication that lower bumper is cracked. Good luck.

If the new trigger valve leaks air when you connect the air supply, most likely defective valve or air is leaking past outer trigger valve orings due to debris in the slot or new orings were cut when the valve was pushed in. If air leaks when you depress safety to fire gun then most likely problem is in the head valve or safety foot is not pushing the firing pin all the way in. Easy test, remove nails and remove the trigger to expose the firing pin. Connect air and very quickly depress the firing pin all the way in. If the gun fires, adjust the safety foot as needed. If the gun does not fire, remove the head and check headvalve orings for good snug fit against the cylinder within the head. The surface were orings make contact must be very smooth and not too deeply worn. If you notice fine scratches remove with fine sandpaper. Reinstall head using plenty of white grease on all the orings within the head and retest. Good luck

Stop using it and take it in for service. If it is leaking air then an o-ring or seal may have failed (most likely guess) and it needs to be replaced.

Time for oring kit # d518005 available at Dewalt service center or at www.toolpartsdirect.com.
May as well order the replacement trigger valve while there. These two items will renew your gun. Good luck

Sounds like a bad O ring. There are rebuild kits you can get with a new set of O rings. Or you can have it done for about $30-50.

Rebuild gun with gasket repair kit.
How it works: Compressed air enters through air hose and fills gun cylinder.
When trigger is pulled, air inside cylinder rushes out and pushes firing pin that shoots nail.

Inside the gun there are gaskets that seal the nose, the trigger and the cylinder head.
When any of those three gaskets fail, then air starts leaking.

Putting a few drops of nail gun oil into gun before connecting hose is supposed to protect gaskets.
But everything wears out, and sometimes folks use 3-in-1 oil instead of gun oil.
3-in-1 is detergent type oil and will cause gaskets to fail.

Another thing is guns that are not used frequently and gaskets get dry.
Putting in a few drops of oil and then immediately shooting gun will cause gasket to fail, because gaskets are still dry.
Best to put in plenty of gun oil, and let oil go down into gun for a few hours before connecting hose and shooting. Even so, nail guns are designed to be used every few days with continual oiling.

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Try getting a can of air gun lubricant from a good hardware or specialist store that sells nail guns. Often the feed mechanism just gets stuck and needs a bit of spray lube to get move again.

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.