2003 mountain Aire air ride dump valve location

You will have 3 of them, one for the rear axle and one at each front wheel. If all 3 are going down close to the same rate, you most likely have bags that are dry rotted and need to be replaced, especially if they are the originals. Is the air in the tanks is going down as well when the engine is shut down, the leaking bags will continue to deplete the air supply until the bags go flat.