The title pretty much says it all. It would be nice if I could find a drawing for both an open type and a closed type master cylinder system.

 

How Stuff Works - Master Cylinder

it's not RX8 specific though.

 

Thanks jowettw. I now understand how the dual circuit works. I still do not understand why each reservoir has two ports and those pics do not help. I believe the two ports has something to do with compensating for pad wear and such but I cannot see how it works.