Great Lakes Auto Works 12/5/2010I've seen the filler hoses crack near the tank. There is also a hose on the bottom of the tank that goes to the right hand tank. Those leak too. It's been awhile since I seen one of these apart so bear with me. On the right hand tank, there is a vent tube that comes off the top and goes over to the fill neck. That'll crack and cause leaks. As far as access goes, you should be able to get to it from inside if I remember right, but If you have leaks you might as well remove the tanks and replace all the hoses.