what is wrong with my bus if when it is off my suspension air bags deflate?
There is a leak somewhere in the air system unless it has something on it meant to deflate the bags
If you have a control (knob, switch) for your air suspension, it could be bad or set wrong. If the air suspension has a levelling valve, it may be bad. If the system has a check valve, it could be bad. If the bus has air brakes and the 2 systems are integrated due to a change made after manufacture (they typically are not integrated new), you may have a bad air valve or connection somewhere in the system. Start the bus and allow the suspension to pressurize. Have a friend start and turn off the bus while you stay near the suspension and check for air as the system de-pressurizes. If you can find nothing wrong, it may be normal for the system to de-pressurize when the vehicle is shut down.
Sounds like you either have a whole in the one of the bags or the air line. Also some vehicles have a one way valve. if yours does it may have gone bad and is letting the air escape.
