2018 Class C 26B. Routine inspection, I discovered that the top seal on the inside of the bed slid out had come loose as the tiny staples that hold the seal to the 1X1 board had pulled out and through the seal. To repair there are three Phillips head screws that hold the 1X1 seal attachment board to the wall. Run the slider out 75% and locate one screw center, and two about 2" in form each end. Pull seal down to find & remove screws. Use 3/8" standard staple gun staples to re-attach seal the the 1X1 board and reinstall seal and board. (suggest marking center screw location on the wall before removing to aid in lining up for reinstallation). Hard to reach the seal and board but can be done standing on the bed platform.