Mystry Water Leak

I don't have the same rig as you do however we had a leak coming from the rear slide area and draining on the floor when the slide room was in. The slide room has a slide topper. I removed each screw that holds down the slide topper individually and then used Lexel (similar to Geocel Proflex) and pumped sealant into the screw holes. I also resealed all the flashing on the sidewall and ensured that the roof was also properly sealed. The problem is in general the OEM only uses butyl tape to seal the exposed brackets which means it eventually leaks. It may be required to remove the bracket to be able to properly seal. If you do reinstall butyl tape as an added level of insurance. I also extended the slide and removed screws on the end holding the flashing onto the rig and pumped sealant into each hole and reinstalled the screws. This helps keep out any water that may or get past the other levels of defense. I’m quite paranoid about water in my rig and chase down any possible sources of water intrusion. It takes a lot of work to chase down water leaks.