Rear window leak fixed! Really? I think so. 1964
My list of spring work on the GT is long and seemingly miserable. Many thanks to those who have shared so much over the years on these forums. What a treasure of information!
The past few days began by thinking about replacing rotted rear floor and fixing the black tank leak and a few other things in that neighborhood.
I decided that it is HIGH TIME to fix that rear window leak that has been pestering me for years. Searches on these forums revealed MY posts from years ago (with pictures!) of MY leak that has never been fixed!
The actual offending leaks were in SEAMS - both horizontal and angled seams in aluminum next to the rear window and all the way up to the roof - here's some of the story about how I figured it out:
Some of the techniques I used to diagnose included putting the shop-vac *blowing* into a hole in the wall to pressurize the space between interior and exterior skin and then spraying soapy water on the outside skin. This turned up some unexpected leak areas (all seams and clearance lights). The kids thought the resultant bubbling Airstream was really cool. Still had water coming in around the rear window though when I garden hose rained on the roof... ARGHHH
Then used different colors of food coloring mixed into water and poured on different levels of the trailer - yellow up to the top of the rear window - red up to the top of the clearance lights - and blue on the roof around the fantastic fan and kept on the roof (mostly) by a "dam" made of wide masking tape doubled onto itself leaving a half inch or so not doubled and stuck together that could stick to the roof.
Then balls of white paper towel inside around the rear window showed where the leak was coming from by color.
That finally paid off by making me look at the roof over and over and finally finding another SEAM that was close to the fantastic fan that once cleaned and re-sealed proved to be the source of water.
It was nowhere near the window where the water was showing up inside. The most amazing part was some of the "blue water" from the roof escaped and appeared to drip straight down the side (toward the wheel well) and puddle on the ground. Later on looking at the rear window I found BLUE residue. Looking closely, it had traveled down and then turned and followed the horizontal seam all the way to the back window. I never would have seen it without the food coloring and I never would have believed or predicted it.
Searching these forums, I found numerous posts by Andy saying that the water goes where you might not expect it and travels in strange directions for no apparent reason, etc. It pays to pay attention to Andy!
Now have dropped the belly pan, removed the box and the black tank, and ready to tackle the source of leaks in the rear end around the bumper, the leaking black tank, and lots more.