Coachman Cross Country Air Brake tanks

Not sure what frame your coach is, but ours is Freightliner. The drain lanyards are on the frame behind the right and left front wheels. You'll have to turn the wheels to get at them. Most likely you'll need something the extend your reach if your not into crawling under the MH. A awning rod would reach. There are two on the passenger side and one on the driver ( on my coach)

Note these aren't to drain them, but to release pressure to check for water.