Does anyone know the minimum amount of air pressure required for the operation of the vacuum generator for the room extension bladders?
Can't answer your question, but I found this page that might be informative. I have no idea what the generator on your coach looks like, but 40-50 psi works best with the generators shown in the link.
Air Operated Vacuum Generators: Air-Vac Engineering (http://www.airvacpumps.com/AVpump.html)
Thank you Chuck. That is more info than I could find.