I have a 1995 d5h with the 3304 engine. I can operate 8-10 hrs and lose 1.5-2 gallon of antifreeze. I have it in my shop right now with all side-shields and belly-pans off. I've let it run and get warm and can't visually see any leaks anywhere. I guess it could be "burning" it. Is there any kind of stuff to poor in radiator like you can on a vehicle such as "bars leaks" in case there is a small leak. And if it is "burning" it, how can I tell? I've put my hand over the exhaust and it doesn't smell of antifreeze.