Gas leak
if you are losing the gas from anywhere on the hosing did you use P.T.F.E. tape (plumbers sealing tape) a better alternative is a hydrolic sealant Loctite NOT thread lock!! I don't know the number I.E. Loctite 123 but any forklift supplier or such like will tell you which one you need.
if you are venting gas anywhere else take it into the shop and let a gunsmith fix it cos you don't wanna start to take a Cocker apart, might be a good learning idea but chances are you will mess up, and just as an after thought you have got an anti syphon pipe on your tank? won't cause a leak but it will cause liquid through at the wrong time and on a Cocker liquid is a real no no.
Hope this helps.
Mark
UK Cougars