For several years the only acceptable way to repair a water leak from the windshield was complete removal and re-installation of the glass. Concern is the potential development of rust in the entire frame of the windshield, especially since the front and rear glass are the structural components of the deck and adds rigidity to an otherwise weak area. It was later discovered that water leaks are the result of poor adhesion between the glass and the urethane, not the urethane for the frame. Consequently, in the early 1990’s General Motors issued a Technical Service Bulletin recommends that water leaks can be repaired from inside the car.
- Sit inside the car and carefully fold the roof lining in the front again the general area where the water leak is. Have an attendant slowly pour water over the windshield.
- A flashlight in the area where the water begins to drip. Catch drops of water with a towel and continue watching until the water stops. Dry the area well.
- Apply a small amount of silicone sealant to the exact spot where the water is leaking. Use only enough to cover the area. Press the silicone into the hole with a cleaning motion. Rub several times around the area and apply another small amount of sealant. Do not apply an excessive amount of sealant.
- Test the repair after allowing the sealant to dry for two hours. Use a flashlight to check that the leak has been fixed.