ORIGINAL: bluestratos
My air tank fill has a special adapter that must be screwed on all the way before it will depress the fill valve. Even at that there are a few robart valves that require some modification or sending back to the factory to make them work right. The adapter will not screw on far enough to depress the valve. I carefully take a file and shorthen the male side (side that mounts to the plane) a small amount then check to see that that air enters. It usually only takes a small amount of filing to get the valve to work.
Regards,
Randy
I had to do mine that way. I used a little silicone to keep the tank in place.
I've used this valve setup many times and haven't run into that problem! But glad to hear you found a simple fix.