Air leak after replacement

[Quality1]

Had my windshield replaced. Installer asked me to leave a crack in one of my
windows to prevent pressure from pushing windshield when doors are closed
thus breaking the seal. Ok to drive after 1 hour. Well i waited two hours
before driving and thru habbit i eventually closed all my windows and closed
the door. i now can hear a air leak. Could closing all windows and then
closing door have caused this? The cabin is not air tight even with the
windows all closed.

[Brent Deines]

It's possible, but in my experience unlikely. Can you tell where the air leak is coming from? Are you sure there is an air "leak", or could it just be wind noise from the outside? What kind of car is it? There are more variables than I could list here, including preparation, primer, sealer, placement of glass, etc., but typically wind noise after a replacement comes from the bottom of the windshield. If from the top or sides you will probably also experience a water leak. If from the bottom a possible cause can be that a weatherstrip was not replaced, or properly replaced. Some vehicles have a large area where the glass overlaps the metal, and a foam/rubber weatherstrip is used to minimize squeaks, rattles and wind noise. This weatherstrip can become damaged when the windshield is removed, and if not properly replaced winds noise could result. If there was also a gap in the urethane at the bottom of the windshield there could actually be an air leak as well.

In some cases the windshield may need to be removed and replaced again, but depending on the type of installation and assuming the problem is isolated to a particular location, the installer may be able to seal the edge of the glass to eliminate the noise you are hearing. Just be sure you test thoroughly for water leaks. Water can follow wires and can seep in behind the dash and under the carpet, making it very difficult to trace to the origin, but you don't want to take any chances. Water causes rust, and rust causes safety problems among other things.

[Glasseye]

A good method of checking for air/water leaks for the top and sides of the screen is to mix together a solution of washing liquid and water and brush this liberally on the outside of the screen at the edges. Then use a high pressure air line on the inside of the car, between the glass and the panels. Any leakages should show up as bubbles on the outside. As for the bottom edge, most vehicles are designed with the glass going underneath the lower panel. Normally this panel should have been removed to allow the glass to be fitted correctly, but some fitters try to fit the glass with with the lower panel only partly removed. This increases the risk of a poor seal on the bottom edge which may not result in a water leak but may cause wind noise. This also will have an impact on the safety performance of the glass as a strenthening factor of the car and also providing the support to the passenger airbag if it is deployed.