[77newell]

There are three tanks. The first tank after the compressor is the so-called supply tank mounted just ahead of the drive axle. From there air is sent forward to the two brake tanks mounted aft of the front axle. Each of these tanks has a check valve in the supply lines going to them. Perhaps one way to tell where to look for leaks is track the pressure decreases in each tank once you shut off the engine. There are two needles on the brake gauge, one for each of the front tanks.