Thanks for the response, but why does it only leak above 2000psi? If it was the seal I would expect it to leak all of the time, no matter what the pressure is. I can leave the gun for months and it still has air in it, it only leaks right after I have filled it and then stops after I fire a few shots?? I will have to get some info on how to dismantle and service it as I have not worked on a Gamo before, thanks again, Neil.