It started out with a musty smell in my inside top front cabinet on the full wall slide. Removed the cabinet back wall and found water dripping from empty screw holes that go into the roof. So I go on top of the slide and remove the slide topper. And I found that where the TPO matrial of the roof of the slide meets the steel frame that seals against the wall slide opening was poorly sealed or no sealent and for most of the length of the slide
it had caused some warping of the wood under the TPO. I also found that some of the counter sunk screws that hold the outer metal edge to the roof- the screws had been driven through counter sunk holes which also allowed water into the slide wall frame. Like most things we have to fix of these MHs if they would have spent 10 minutes longer or spent 5 bucks more we wouldn't have the problems. To fix it I slit the TPO roof material and let it dry out. Then sealed the slits with Eternabond. The outer edges and the screw holes with Dicro sealent.
And then I'll pull the slide topper off my bedroom slide and check the sealing on it.