check valve on vacuum advance?

[Griffin]

car is an 84 318i

http://www.realoem.com/bmw/showparts...33&hg=11&fg=45

See part 1. I looked here and noticed my hoses are actually routed backward compared to the diagram. Is this a check valve too, or just a vacuum solenoid?

I'm still trying to nail down a vacuum leak after replacing all small vacuum hoses