I probably didn't make my self clear. The breather for the subframe tank runs between the tank and the frame as well. I wonder if there is enough room for both and if you could fish the brake line under the tank without taking it off.
I'm sure there is room. The brake line does not take up much room. As far as routing the line you do not need to take the tank off. You will figure it out when you go to put it on.