[ron skeen]

I think all air goes through the dryer in the drive side. It then goes through the rear supply tank to all both brake tanks which have one way values to keep air from going back into the systems. You must have a massive air leak some were that the supply tank is trying to fill. Your air compressors engine and 110 must be working or you would have no air in the bake tanks. You have diffidently got a major leak that you should be able to detect. If the small tank in wheel well has no air check in that area.