hey... I have the same problem with the cruise control, and I think mine might be the vacuum servo unit. The reason I say this, is because I think my entire vacuum system is shot. The locks don't all work, I have to lock the passenger side manually, I had to disconnect the gas cap lock because it would stay locked. I am wondering how much the vacuum system would be to replace/repair. It is a minor inconvenience now, but I wish it were an easy fix.