There's one on every GU that I can recall but must admit it's not something I go looking for... and it's been a while but I could almost swear there was a factory one on my TB42EFI GQ wagon as well... not 100% on that now as too many beers ago.
On a ZD30 the pipes travel from the Power Steering on the RHS down and along behind the radiator and then hook up and thru the front on the LH side below the air box. The fluid travels thru the cooler twice in effect because when it gets to "the other side" it loops back and comes out on the LHS again.