MCI MC9 air dryer

[solodon]

Thanks for the clarifications.  I do not hear any air hissing after the blast.  The bus is being gutted right now but I've driven it a bit before I started work in it.  The reason I brought this up was an earlier post which got me thinking.  Never a good thing.  The bus is situated such that even if it were aired up my portly body wouldn't have enough access underneath to spray any soapy water in search of leaks.  right now I'm stock piling the information you're all sending so I have a starting point when I finally get to do something with it.  The bus drives fine, the brakes work well, the bus stays up when running.  It's when I shut it off that the air will drop to 0.  Thanks again for all the information.  I'll start this again when I've had a chance to check things out.