DEWALT DWFP12231 Pneumatic 18-Gauge 2-Inch Brad Nailer leaking air through the trigger. Still fires brads but can constantly hear the air escaping through the trigger.

SOURCE: Nailer jams with 1-5/8 brads

It sound to me that the 1 5/8 brads are not 18 guage but probably 16 guage and they will not work. Double check them first before going any further. You can usually lay them next to the smaller ones that work and see the size difference, if not let me know and I will dig deeper.

SOURCE: Porter Cable 2 inch brad nailer piston does not return

Hi,
Sounds like the cylinder check seal. That`s the o`ring on the outside of the cylinder sleeve. With little holes in the groove. You have to remove cylinder sleeve to get to it.
Thanks,
Jeff

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: how to remove brads jammed in the nailer

Open the top where the plunger is...remove the jam and push the plunger back..close up the gun and you should be fine. Make sure you disconnect your air hose first!!!

SOURCE: My braid nailer will not fire. I can hear air when I pull trigger but it will not fire, almost like it has a brad jamed in it but do not see one?

Most likely stuck driver or headvalve. Easy fix. Remove the head, pull out the driver and check for bent shaft, if ok, lube and reinstall. Next remove the valve within the head, lube and reinstall. Replace parts as meeded. Retest. If it still does not fire, could be that the safety foot is not pushing the firing pin all the way up into the valve. Easy to check. Remove the nails, remove the trigger to expose the firing valve pin. Dry fire the gun by quickly depressing the valve pin with finger. If it fires, adjust safety foot as needed. Parts are at www.toolpartsdirect.com