[Mikendebbie]

This simplified sketch sort of illustrates the problem with tanks draining faster or slower. Tank "A" is mounted in the drop frame section of the vehicle frame and it is at a lower elevation than Tank "B" which is mounted higher in the coach frame. Tank B is going to have more head pressure to empty quicker. That is the way is in my my RV. I have a black and a gray tank in the "B" location. They both drain great, whereas my black and gray tanks in the "A" location drain much slower. There are several youtube videos of Montana factory tours, and you can see the tanks mounted in the frame like this. In one of the videos the factory rep says we should raise up the front end of the RV to get better drainage out of the tanks in location A.