I don't know if I am posting this is the right place, but my local volunteer fire department has a M931A tractor, they knocked the air lines off of the tank on the passenger side right behind the can. Instead of calling me then they took it all apart and brought me the air tank and a handful of broken fittings. I have been looking for two weeks for information on the line placement, and ran across your site. I am hoping someone out there has one of these trucks that might send me a couple pictures so I can get everything back together. I know this was a long post but I would appreciate any help you can give me.