Leaking A/C high side schrader

[KennethS]

you need to have the right tool for your valve core size, then you need to "adjust" the slot in the end of the rod so it grips the valve core. Use a new core to get the slot opening set correctly, then when you are removing the leaky core you can feel it "snap" onto the core before you unscrew it. If you have the right tool, the core will go through the ball valve section with ease.