Try this. Turn your gun on with the eyes off (hold in trigger while turning on). Make sure theres no paint in there, or at least nothing in the way you dont want to hit... then fire it until the thing stops leaking.
Sounds like your bolt is sticking open, a very common problem when they sit for any amount of time or when first using them when it's cold. Use dow33 (sl33k or hatersauce etc) as this seems to reduce the sticking in these mini based markers. Also be careful not to use too much, the tm15s especially seem sensitive to this.
Hopefully this solves your trouble! Good luck.