Wntrgrn1-
I too have a window leaking water and removed it yesterday.
My leaking Bighorn 2985RL window was on the side of one of the slides. I don't believe the location of the window matters, as they all mount and seal the same. Mine was leaking water which was soaking the carpet.
I used a garden hose to spray the window suspected of leading, being careful not to spray any other area, in an attempt to isolate the leak. After spraying the window I checked the carpet and it was wet. No surprise....but this confirmed my suspicion that this was the window which was leaking.
I removed the window. The window has a thin rubber gasket running around the entire flange which mates to the outside skin of the trailer, on the outside half of the window. The gasket is very thin and I'm not surprised it leaked.
When we got the trailer a year ago, the windows were all installed with the inside ring tightened so snug, it was impossible to slide the sliding portion of the windows. The dealer loosened the screws on the inside portion of the window so the sliding portion of the window (on the bottom of this window) could move up and down. My suspicion is the gasket was compressed when the windows were originally installed, when the dealer loosened the window frame to the slide portion could move, the gasket failed to expand, and it now had a gap allowing water to pass.
If you look at the outside of the window, only the top of the window and the top radius corners are caulked. I believe rain water was allowed to seep in through the sides.
Having the window removed I looked at the bottom of the window opening of the slider. I could see, and feel, wet fiberglass insulation. Now I was really getting the feeling I was on the right track, because the wet insulation showed the water was leaking past the window, and the water was running down the inside portion of the wall, down to the carpet.
Today (Thursday 7/5/12) I talked with the dealer and they confirmed this is a frequent problem. I asked if it was necessary to install a window manufacture replacement gasket and they said no. They told me to use the roll of puddy tape all round the window ridge and if I wanted, also caulk the outside edge of the window, not just the top and top radius.
I'm hoping to install the window tomorrow and I post an update on the results.
From a fellow outdoorsman, hunter & fisherman.
Chris in Idaho