So our bedroom slide leaks when it rains hard. 2012 Crossroads Cruiser. I've checked the three seals and all seems to be well, and they have been lubricated since new. It leaks in from the bottom rear...
I had a problem with my bedroom slid as well as the dinette and living room slide. Turns out it was coming from top. It was running down the inside of walls and the carpet was wicking. Still under warranty, took to dealer and the replaced the flashing tape on top. But realized the factory did not caulk the side by facia. So the water was getting underneath and working its way down.
Also I had a window from the factory that was not installed properly.