If the weatherstripping came loose around the trunk lid or one of the car doors, would you be able to repair it? If you were replacing a leaking valve cover gasket -- not a difficult task -- would you use a gasket sealer? If so, what kind and where?
They're easy questions for mechanics, but not for average do-it-yourselfers.
There are literally hundreds of adhesives and sealers that can be used in automotive work. Here are a few that will help you handle most of the jobs you'll encounter.
WEATHERSTRIP ADHESIVE. There are various brands, but 3M Super Weatherstrip Adhesive is the one I'm familiar with.
It comes in a tube and works extremely well for attaching new weatherstrip, reattaching old weatherstrip that has come loose, and for re-attaching stick-on side moldings that have a case of the sags.
GASKET SEALERS. There are many of these around, too. But you need only be familiar with two to handle most any gasket job. Two widely used in automotive industry are Permatex No. 1 and Permatex No. 2.
Before installing a new gasket, make sure both metal surfaces are free of any old gasket material or sealer. Use a scraper or wire brush to clean. Don't use sandpaper, as this can leave invisible abrasive particles.
Here are some of the more common automotive gaskets and tips on replacing them.
CARBURETOR GASKET. This one is replaced dry. Use no gasket sealer.
VALVE COVER GASKET. It it's a neoprene gasket, use no gasket sealer. It it's a cork gasket, use a light coating of No. 3 on the valve cover side of the gasket.
TRANSMISSION PAN GASKET. Use no gasket sealer. It can ruin a transmission.
HEAD GASKET. If the gasket is already coated, use nothing. It it's a non-coated metal gasket, use No. 3 on both sides.
WATER PUMP GASKET. Use No. 3 on both sides of the gasket.
When you have a broken or leaking gasket, and can't use a replacement gasket, try No. 1: Coat both sides of the gasket. No. 1 hardens and becomes a kind of gasket itself. No. 3 remains semi-hard. Ordinarily, any time you disassemble a part that has a gasket, use a new gasket when reassembling.