For folks who haven't seen this done .... We had the seals around the slideouts replaced under warranty at the Monaco factory service center in Harrisburg, Oregon. Before sending us on our way, they leak tested all the seals. To do this, they rolled a large frame with numerous water jets so that it stood over the slideouts. They hooked up a water hose, turned on the water, and let it spray water for some time. They have a different setup to check for windshield leaks. Not very scientific, but works as a simple leak test.