using the stk 4 piston caliper?

People say that, but doubt any have used DOT 5. If this mythical moisture is a concern, wouldn't you have the same issue in your power steering system? I removed the MC from my 65 Chrysler after using DOT 5 in it for 15 yrs and not a spot of rust inside. I was simply changing to a dual reservoir MC.

I didn't throw it out there for debate. It's a well known fact. You can find that information anywhere on the net where Dot 5 is talked about. Even on manufacturers web sites. It's no secret and never had been. We've even had discussions on it right here on this forum.

If you do a search you will see.