I have a handful of questions swirling in my head for the new rig I just bought. The coach is still down in Phoenix getting an exhaust brake added so I'm doing some of this from memory.<br/><br/>Is 120ish PSI still the correct setting for the governor on these coaches? The PO had it turned down a bit to 100psiIs there any reason I can't add a valve that lets me dump the air out...