2020 4007 Leak Follow-up


Well-known member
Thought it would be easier to start a different thread since my first one never really answered my question.

When it rains, I have a leak which comes out of the porch light above the door (dry above the door) and on the top of the door frame inside the trailer.

Pulled the inside trim above the door and the butyl tape that is supposed to be between the door top flange and outside wall never made it there. It is laying on the frame above the door in the gap. I thought the water running out of the light was leaking into the top of the door and into the trailer. Held a towel under the light and the water still runs into the trailer telling me there is water in the wall.

Got up top today and the membrane looks good but I do have some possible leaks around the skylights, vents, etc.... See pics. Gonna reseal all these areas after I do a hose test. What do you suggest I use?

The leak is directly in line with the center AC unit. I’ve had leaks at the AC before on other trailers but it always leaked at the AC inside. Are these style AC units hard to reseal once you pull them?

The rail for the awning looks solid but it only takes a pinhole. Going to get a closer look with a ladder. Are the top rails sealed with butyl tape or silicone or just screwed to the side with silicone at the screws?

Trailer is currently in Angel’s Camp, CA, about 3 hours away while I work out of town. Going to drag it home Wed or Thur as I will be dragging it to Phoenix on Saturday for the NASCAR finals. I’ll do a hose test. Start at the top of the door, then along the top of the awning, then around the AC unit, then at each area where the rubber sealant is. I’d rather know where the leak is coming from vs sealing everything at once and not knowing.

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Any other suggestions?


Well-known member
if mine I would be cleaning up those sealant joints with good cleaner & then apply some Dicor on those dark spots/small holes. Been doing that on our RV for a few years , so far so good. Dirt is what's causing those dark spots & the will lead to a hole/leak. Good luck


Well-known member
If you pull an A/C unit, replace the gasket. Don't re-use the gasket you pull. Use care when installing the new gasket.
The gasket should be compressed to about 1/2 of the normal size.


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So just a shot in the dark here.....

You don't say if the leak occurs with the awning open. That could be in important clue in finding the source. If no leak when open, the problem would probably be below that point.

So if no, I would carefully inspect the porch light to be sure water isn't getting in at the top or through a crack in the light fixture. You can also pull the light and probe in the hole where the wire comes out of the wall for moisture.

If yes, I would inspect the track that holds the awning to the trailer. While I never had a leak, I have had some screws pull away and a few that the factory put in too tight and weren't grabbing at all because of over tightening. I have even had a screw in the awning arm completely missing leaving a open hole behind. I would check all the screws and then re-caulk the whole rail anyway.

The next suggestion is based on pictures I saw on line of a Cyclone 4007. There appears to be a light between the AC and the wall just a little further down over the table. If the AC duct is not in the way (hard to tell), I would take down the light, attach a piece of paper towel to the end of a probe stick (I would use a crawl stick because they are somewhat flexible) and probe the area for dampness. Starting on the AC side and working towards the door, pulling the stick out each time to verify damp/dry before moving closer to the door. It may prove weather or not water is coming in at the AC without having to pull it.

Hope that helps.