One Piece Windshield Leaks At Top Quick Fix?

That windshield area is subject to a lot of condensation, especially during Winter months. This condensation will run down the windshield and puddle on the dash and stain the curtain.
Also on many coaches, the top fiberglass cap is not well insulated and this also will cause condensation.
Then there are the leaks that can come from your yellow clearance lights above your windshield.
The last thing I would suspect is a windshield leak, but they do happen from time to time. A way to check it is to put tape over the top of the windshield rubber and see if that stops the leak. Almost any type of tape can be used from masking tape to packing tape for a quick check. Do not leave the tape on permanently because the longer it stays on, the harder it is to remove.

If windshield leaks around the gasket there is no quick easy repair. I had a leak in my new MH. Glass guy came out couple of days after it rained. Had a vacuum tool with a long metal stem. Vacuumed out all moisture around the gasket until it was totally dry. Then applied sealer. The glass guy said re sealing without removing all moisture will not fix the problem. He spent about 4 hours on my front window.

If this is a Class A ,Winnebago glues the windshield to the steel frame. The rubber molding is not for sealing and is strictly cosmetic.
Winnebago has a known problem with the steel frame rusting which pushes the windshield out slightly causing leaks and cracking of the glass.
I had to have both sides of mine replaced. I had Winnebago do it and they removed the rust and applied a rust converter/sealant to the frame.
If that is your issue you need to get the rust taken care of before the frame is damaged too much. If bad enough that is an expensive thing to repair.

Ours leaked, went to a automotive glass shop. The drove a pick-up truck sideways in front of it and then put a step ladder in the back of the truck. The owner of the glass shop used something in a tube in a caulking gun. Said it would seal the window perfectly, but not harden up. Took him 30 minutes, it was cheap, and haven't had a leak in three years so far.

Go by a couple of glass shops, you might even find one that works on restorations, take a couple pictures of your windshield on your phone and talk to them. It's a lot easier than doing it yourself and for very little money.

Bill

The more curvy a windshield is the harder it is to get it in place to stop a leak. I had my windshield on my Winnebago resealed several years ago. Caulking and seals were installed by Novus the windshield couldn't be moved because they are glued in and Novus said most of those windshields break when they are moved. Sounds like you fixed your problem! I also bought a dehumidifier that I keep between the split windshields to keep inside water out and off of the windshield frame. The Winnebago Windshield frames are known to rust out over time so you want to keep condensation out of the inside of the front windshield.

It may not be the windshield. Often, when the windshield is leaking, it runs down the inside of the glass and will be wet against the windshield, unless yours is slanted toward dash where you're seeing water.

What often causes this leak are the running lights. They loose their seal and the water comes in the front cap and drips down on the cabinetry and curtains.

It will be a pain, but you need to identify what is leaking. Often you can run a piece of duct tape or even a wide roll of blue tape across the top of the windshield and see if that stops the issue. If it does, you need the windshield repaired, if not, you need to look elsewhere.

Can also be the clearance lights above the windshield. Regardless need to find someone familiar with fixing winnebago "windshield" leaks. Had one a few years ago that took about 6 efforts.mine leaked in both places and water ran down in the same area on the dash.