Park the RV or camper on a flat, dry parking area. Let the camper or RV cool down. Spread newspapers out underneath the RV where the tanks are stored, typically on the rear, right-hand side.
Open the holding tank panels on the outside of the RV and locate each tank. Wear rubber gloves and do a visual and touch inspection of each tank at the seams and valves. Check your gloves for any water or moisture upon the inspection, indicating leaks at the seams, caps or valves. When checking the black water be aware you are checking for leaking sewage waste water. Take safety precautions with the gloves.
Check the newspaper every few minutes to see if wet drops appear over the surface of the paper. If present, you have a leak. Follow the leak directly above the paper to determine if the leak is in the fresh, grey or black holding tank.
