A slide leak whenever there is a slide involved is not uncommon. If you are sure it's the slide you should take a good look at seals. Sometimes the combination of flap and bulb seals just aren't right. If you are at whits end if it were me I would use some duct tape and tape the entire slide if you can, drive the unit int he rain and see if it stops. If it does then you definitely is the slide. Then I would remove the top and drive again. Keep eliminating till you trace down the area. Most likely the bottom or front of slide. Only way to get it does is process of elimination. Good luck.
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