leak at window over bunk cab

The correct way to fix it is...... take the window out. Clean and dry all surfaes. Apply a bead of new butyl putty tape all around the window. Install window. Seal top and sides with Dicor or Proflex sealant.

Take this for what its worth. I ordered my 'C' new. When it came in to the dealer, I took a walk thru, but the dealer rep said that they had some more prep to do. They said that the builders use high speed power screwdrivers to install the marker lights. It sometimes causes a hairline crack to form that's covered by the trim rings. While I was there, they removed the chrome rings, caulked around the lights, and re-installed the chrome rings. I've never had a leak in over ten years.

Had similar problem on side window of bunk - the source of the leak isn't as simple as water dripping off your gutter - could be anywhere on the roof and traveling to that location. In my case I first removed the window applied new butyl tape and caulk -- didn't fix the issue. I ended up having to use Eternabond tape to seal the edges and caps of the RV.

If it were me I would take the rig into a place which can pressure test your rig - should determine all the potential leak points in the rig and it only cost about $100. Just my 02.

I would not guess at where the leak is from, spend $100.00 and have a dealer perform a pressure test. Fix all of the sources at one time. My dealer allowed me to observe the test and after I photographed all of the bubble locations and was able to end my leaks problems. Good Luck

I installed a set of these Camco gutter spouts (Style: With Gutter Spouts) at all 4 corners. I prefer these over the gutter extensions - which just slip on.

After I had the roof replaced it had short, stubby, gutter spouts and I did not like how the rain ran down the side of the cabover.
I removed the screw at the end of the gutter track,
removed the old spout,
lifted the end of the gutter track just enough to clean out behind it a little bit,
added sufficient amount of sealant,
inserted the long gutter spout behind the track,
and reinstalled the screw at the end of the gutter track. I like the idea of the spout being screwed in place.

I wanted long gutter spouts because in a heavy rain it will perform like in the below picture (from amazon). In a lighter rain the water will actually wrap under the spout and travel up the underside of the spout for a quarter of an inch or so, before dropping to the ground. I wanted gutter spouts that were long enough to allow this to happen without the water touching the side of the cabover.

Yes, it's not a look that I prefer... but IMO this is a case of function over form.

I am having almost the same exact problem you are having. Have probably spent 30 hours taking out/resealing windows, replaced all the running lights, resealing (and sometimes taking apart) every joint that I can thing of and still have water getting in the cabover. I have the bottom trim piece off under the cabover and have it temporarily taped over when it rains. After every hard rain after pealing back the tape there is moisture at the bottom of the cabover. Just a note on the sliding window - mine was leaking from the bottom also but when I took out the window to reset it the water was actually coming from above the top of the window frame and running around the frame and leaking out the bottom. I agree with the others to get a pressure test. The closest one I could find that uses the SealTech system was Stymeist Collision Center at 3948 Highway 49, Placerville, CA 95667. Don Hinshaw was the contact at 530 644-7703 They quoted me $150.00. For the time being I am going to try to rig up some kind of leak test system of my own and if I can't get that to work am going to take it down to them. Hope this helps, Jeff.