Originally Posted by gocmndo
Anyone ever have the air brake switch leak? My bus use to hold the pressure in the tank for days. Now it is all bled out in two or three days. When running with the brakes engaged it is fine, when I push in the brake release I can hear air escaping.
Air brake switch? Do you mean Stop light switch? Yes, they can leak. As far as the rest of you question it is unclear what you are asking exactly.
Here is something that will help you understand how the air brake system works and what components make it up. After you look at this it might help you to better understand and explain what you are experiencing.