Bummer about the leaks. Those are rare, but when it does happen, I believe it is usually caused by the O ring(s) just inside where the air cylinder screws in. That brass fitting can be removed with, if I recall correctly, an 8mm deep socket. If you are careful, you can remove it without removing the action from the stock, but if that is necessary, it is pretty easy. When you replace it, screw it down tight but not too tight, otherwise it will collapse the O rings. Replacement O rings can be purchased from the UK in a set for the entire rifle. It is typically less expensive to buy the entire kit rather than just one O ring from PA. Is your rifle the Beeman or the Weihrauch? Sadly, sometimes the Beemans can have a bit less QC than the Weihrauchs. Something else to consider, AOA has, or used to have a lifetime warranty on the Weihrauchs if purchased from them. Their service and tech dept. may be able to help more. If the rifle is in your hands, you can verify if the air cylinder is leaking by removing it and filling it up and seeing if the pressure eventually drops or not. If no pressure drop, I would suspect it would most likely be the aforementioned O Rings and probably not one of the more finicky ones to get to more inside the gun. Hopefully this might help trouble shoot the issue. Unfortunately, O rings are usually the culprit in anything that has O rings, from PCPs to bike and motorcycle shocks and forks, etc., I know you get it. Accckk! LOL Hope you can get it fixed soon and love the rifle too. :~)