I'm very new to airsoft and I bought a gas pistol about a year ago and I've come back to use it and when i try to fill it up with gas, theres this constant leaky sound/blowing. As if air is constrantly being thrown out, alos the air being thwon out and the air from my can isn't cold at all. From my research i thought that the problems are my can is empty, and it looks like i dont have any O-rings where i re-fill the mag. Could someone look at the picture and help me?