[Frank Coppola]

Bob,

I was hoping you would reply as you have saved me in the past. Running a line from the 1/2 NPT fitting at the top of my water neck to the port B (below the rad cap on the expansion tank) is a bit redundant but it can't hurt. It's effectively the same as pluggin it as bad_sss suggested. This is a perfect example of spending too much time thinking about something- I tend to forget the rule of K.I.S.S.

Now, since you are an authority. Please explain this: The port at the radiator cap (affectionately referred to as port A in my case) would vent fluid when the system builds more pressure than the cap is rated for. Therefore, since there is a spring in the cap forcing the valve to close once the pressure is released, there is no way to recycle the fluid back into the system. Right? This was my understanding, but Zderf and Tovio say no.

Thanks guys!