Gaskets are typically replaced when repair work involves engine disassembly (removing valve covers, intake manifolds, oil pans, timing covers or cylinder heads), or when an engine develops an oil, coolant or vacuum leak. Selling your customer some type of gasket set is usually the best way to make sure he gets all of the gaskets, seals and other parts that may be required for a particular job, but you also can sell individual gaskets, too.

Gaskets come in a wide variety of materials and designs, so there is often confusion as to which brand of gasket or which type of gasket is “best” for a given application.

The best gasket is the one that fits correctly, seals without leaking and maintains that seal for the longest time.

One aftermarket gasket manufacturer may use a different material, coating, design or type of construction from that of another manufacturer for the same application. Either gasket may work equally well — provided both are made with high-quality materials and are properly engineered for that application. But in recent years, an influx of “copy cat” gaskets and gaskets made with lower quality materials has invaded the aftermarket. Many of these lesser quality gaskets are made with materials that take a compression set and lose their ability to maintain a leak-free seal over time. That, in turn, leads to consumer complaints, comebacks and loss of confidence in the products you are selling.

The solution is simple enough: recommend brands that are committed to producing quality products that are properly engineered and made with the highest-quality materials. Yes, top-quality gaskets may cost more, but your customer gets more for his money. He gets a gasket that fits and lasts and won’t fail anytime soon.

Molded valve cover, oil pan and intake manifold gaskets are commonly used on many late-model engines. Some of these have plastic or steel carriers for reinforcement and to make installation easier.  These gaskets are supposed to be long-lived, so it is important that they experience the least possible compression set (say no more than 15 to 20 percent). Yet some cheap-quality gaskets experience a 40 to 60 percent (or higher) compression set.

One tip you can pass along to your customers is that molded rubber gaskets should be installed DRY. Some may require a small dab or RTV sealer in the corners to seal a seam, but use of RTV on molded rubber gaskets or coated gaskets should be avoided because it will only cause problems.