I had to replace the fuel pump in our 1990 740 Regina a couple days ago. In the process, I noticed a little gizmo that sits on top of pump and the fuel flows through it as it exits the pump. It has an oval shaped metal sort of diaphragm looking thing on the side of it. At first I thought "check valve", it's a straight-through thing with no ball or flapper or anything that you would expect to find in a check valve. Does anyone know what it is?

Also, where is the check vlave in that system? Is it integrated into the pump?

FYI - I purchased a replacement pump at Advance Auto for $56 which I thought was a very good price. Plus it was an excellent (exact) fit. With a new pick-up screen, I got out of the store for about $61. Oh yeah, they had it in stock on the shelf. Not bad for your typical Chevy-Ford-Dodge auto parts store. It must be one of those Regina parts that are common to a bunch of Chevy Cavaliers or Buick Regals or something.