Originally Posted by Lawpass
Make sure you cock the marker before airing it up.
It seems unlikely that its valve spring is worn out, but I guess its possible. By any chance did you look at the face of the valve while you had it out?
yes I looked at the rim that the cupseal contacts with it is 100% perfect no scratches nicks or anything wrong with it. Its odd because I unscrewed the valve pin from the cupseal about 1cm and the leak stopped but as soon as I shot it it came back. Its a very slow leak, and can only be heard if you put your ear to the feedneck. Also I am cocking it when I air it up. I'm low on air but it does this no matter how much is left in the tank.