2008 Audi TT Coupe Back Windshield Leaking
This Audi TT Coupe located in Austin, TX was having issues with water getting into the trunk area. The problem is actually pretty common. There are a few things that can cause this.
First, you need to find the source of the leak. This process can take time and you don’t want to take any short cuts. I have seen many failed repairs. It is easy to assume that if water is entering the vehicle, it must be the glass that is leaking. This is not always the case.
To properly diagnose the problem, remove all interior trim from the trunk lid which is two sections. The thin section that runs along the top of the glass and half way down the sides is held in place with clips and one screw where it meets the lower trim section.
The larger section covering the bottom is also held in place with clips and there is an additional screw inside the had grip in the middle.
With all the trim removed do a visual inspection of the glass and look for any signs of water or obvious damage.
This Audi TT had no visual leak or any sign of water around the glass.
Next, we need to test the back glass for leaks to be 100% positive we can rule it out as the source of the problem.
The best method for finding an auto glass leak is the pressure test. Done with two people it requires a spray bottle and compressed air.
Have one person inside the vehicle with the compressed air hose and the trunk lid closed. Using the spray bottle from the outside, spray the pinch-weld. Make sure to only spray the gap between the glass and the body of the car. Using the compressed air, blow around the inside frame of the glass.
Below is a close up view
Watch carefully, if there is a leak the air will blow the liquid and you found your leak!
After testing this vehicle, the back windshield was not leaking.
Next, we moved onto a water test to try and replicate the problem. We used a water hose and covered the back of the car. Right away there was water entering the trunk lid. (See below photo circled in red)
This vehicle is equipped with an automatic spoiler that sits flush to the body. Once the vehicle reaches speed the spoiler will lift powered by an electric motor mounted in the trunk lid.
There are water drain hoses designed to divert the water, but overtime they can clog or break. In this case, these hoses failed and that was the cause of the leak.
Circled in RED on the diagram below shows the leak. Figure 6 is the water drain hoses.
Check out detailed photos of the front Windshield Replacement on this same Audi TT.
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