Hatsan T/S leaks on a .30 cal Hatsan Hercules Bully

Hatsan Hercules Bully Leak

I am clueless on how to t/s huge leak on my Hatsan Hercules Bully .30 Call. When charging my Hatsan Bully, I can feel air blowing all the way back to the receiver area, and I can hear something rattling in the cocking mechanism area (body) when I move barrel up and down. I do appreciate any help/suggestions on how to t/s and fix it.
Went to hatsan website, they do not have any "How to Videos".