Unstoppable Coolant Leak

Charlesvolare said
Bought it brand new a little over three years ago and have had zero issues until recently.

I had a 16lb cap on at first, then a 7lb. Didn't make a difference. No Roll pins, RTV to seal china walls to intake.

If that's the case, I'd suspect gasket failure. Maybe you need to use a thicker/better gasket as mentioned. Even still, I would check it ALL out as I outlined.