[blykins]

It’s already broken through, that’s why it’s leaking. Two BBM blocks that I have here are like that. I caught one when I primed it. The hole isn’t that big, prob .060” or so, but it’s enough.

The fix is what I described up above. Put some silicone in the hole, put some under the bolt head and washer.

I also think you could get a short 5/16-18 set screw, coat it in silicone, then screw it all the way in until it bottoms out, then bolt the adapter on.