Testing heater vacuum "motors" (Type-44)

[Ameer Antar]

I was just going over the heater assembly as I'm taking it apart and noticed the vacuum motor (as Audi calls it) that controls the heater/defroster flaps is not holding it's postion well. The test I did was just to push the lever all the way and cover the vacuum port and then let go of the lever. The lever returns with not much resistance, so I'm wondering if the diapragm isnside is shot. I did the same test on the other vacuum motor and it seems to slip very little, which seems to make sense b/c I'm not applying vacuum. So is the other motor supposed to act differently like that? Do I really need a mighty-vac or other tool to test this? Anyone have any sources for this (hopefully not in the same condition)??? Thanks.

-Ameer