Hi Bill~
Yes, it could make sense....any way to ask the previous owner?

When I started trouble shooting my vacuum issues....I disconnected everything that "needed" vacuum and then took my reading.....I then started reconnecting devices and hoses one at a time to determine if I had a leak...."lost vacuum."

You can make assumptions all you want.....have you had the transmission serviced? What did it look like inside? New filter....etc.?

Nathan