I was looking at Cossie Daves plumbing yesterday after discussing with Mark the pressure on my system and I can see that a lot of the headers have 3 pipes, mine has 2, a feed and a return from the turbo.

Why do they have 3? This could be my issue?
My car has an ally updated pug 205 rad, the expansion line is blocked off, I wonder if the rad should have that connected back to the expansion tank as well as the return from the turbo? Mark said to plumb it like the Cossie.




I have circled the 2. I bought a standard Sierra expansion to try and that has only 2 in total.