My guide to replacing the rear window seal on a classic car, because a leaking rear window seal is one of the most common sources of trunk and interior water damage.

The removal: the seal is held in place by a continuous bond between the rubber seal, the glass, and the body pinch weld. The correct tool is a seal removal tool — a paddle with a thin edge that cuts the seal without damaging the glass or the paint on the pinch weld.

The installation: clean the pinch weld surface, apply a thin bead of seal adhesive around the perimeter, seat the new seal starting at the top corners and working around. The seal has a channel that accepts the glass; use a nylon roller to seat the glass into the channel around the entire perimeter.

Pressure-test by running water around the window after installation. Test twice: once the day after installation and once after the first full heat cycle.