Leak in bay door

[BillDeb45]

I have a 2004 Monaco Windsor 40’  the drivers side second bay from front has been leaking  Its coming from the top  I have attempted to seal along the outside and no success  

[jacwjames]

I believe your doors swing up.  The hinge is a two part aluminum extrusion.  One part is fixed to the side of the motor home and the other attached to the door.  The mate together to allow it to act as a hing.  Hard to imagine how water is getting in there but I'd suggest you check your belt molding that runs across the top of the hinge.  If water is getting into the belt molding it can get behind the fiberglass and leak down on top of the door. 

If it's not that it could be a leak around a window and migrating down inside the fiberglass.  A leak like that you result in delamination, which would probably be visible on the outside unless it just started. 

I had a small section of belt molding that was not sealed on the passenger side rear of my coach at the top.  The leak did migrate down to the door below.  It was a pretty good job to fix it, had to remove the belt molding all the way around & up the back.  Most of the screws were rusted out, I replaced with SS rivets.  I did have some delamination and repaired with epoxy, had to get creative since it doesn't run uphill, I places it with compressed air and copper tubing.  Somewhere on here is a post I had done on it.  Came out pretty good, not perfect but pretty good. 

[Frank Bergamo]

Are you sure it’s an outside leak penetrating the door seal or possibly a plumbing leak getting inside the bay? When does it leak? After a good rain or washing coach, or randomly? When running pump? Once you figure out when it is leaking, then you can figure out next step. Hope this helps.

[BillDeb45]

Only noticed with rain

[jacwjames]

The way the hinge is constructed it is unlikely that the water is coming in from there.  It is probably seeping in from above. 

I'd start looking for a problem/leak above that.  Water runs down hill but in an RV it can migrate from pretty much anywhere.

Look at any windows to make sure the caulk is good all the way around.  I've had several of my windows out while repairing the fogging and/or bringing my refrigerator in the coach.  On my rig Monaco used a compression type seal on the windows and the caulk around the perimeter.  There were several windows that the compression seal was barely overlapping the side of the coach.  A real opener for me.  So I make sure the caulk seal is good as a primary seal. 

Belt molding caulk can be checked also.  I spent ~3 days last year cleaning out all the original caulk/sealer on my belt molding last year and resealing with Geocel.  I used these long hard plastic scrapers, they worked great.  https://www.harborfreight.com/4-piece-nonmarring-scraper-set-95832.html 

After cleaning the old sealer off I wiped down with solvent and the taped off the seam before laying a bead of caulk and smoothing with my finger and then removing the tape.  I tried a small section without taping and it was a disaster so I went with the tape. Took a little longer but finished job looked good. 

 

[Paul J A]

Take some food coloring, dilute in water,  and spray the area you suspect a leak may be at. It leaves a trail when it drys.

 

Edited September 18, 2022 by Paul A.

[BillDeb45]

Thank you