I have a 2018 Cyclone Model 4005 in which the rear black tank has started leaking. Since black tanks are made of many different materials, I need to know what the tank is made of to make repairs. The leak is somewhere under the corlpast underbelly. The water runs down the pipe then drips off onto the floor. I know I am going to have to cut an "access hatch" to get to the tank connections. Any help would be greatly appreciated. I called Heartland and they referred me to Ameri-Kart who made the tank. I called Ameri-Kart and they said leave a message.