Ok, I here what you are saying. But I can't run it anywhere as I have got no brakes. Unless as you suggested it has the other one as a dual curcut? The other tiff that worries me, is that the brake pump is running all the time now, if you do think that it would be able to run it up the farm. (Slow & gentle I might add)
You should always have hydrostatic front brakes providing you have fluid in the tank. And of course the transmission brake The rear brakes only work from the pressure system. Obviously the less fuel in the tank the lighter it is.