On my 1988 S4-NA where's the exact location of my Air Separation Tank? do I have one or not? My coolant reservoir is purging out coolant and it's not sucking it back. Filler neck and radiator cap which one needs the flat cap? I researched the web asking for the exact location of my AST but nobody posted a picture of it. Thanks.

 

FC's do not have an AST.

 

Thanks for the info.