Today's diesel engine is a  hard-working and efficient power plant designed to provide many hours performance. But an engine's life is directly related to the amount of care put into it. Fuel and lubricants-the lifeblood of a diesel engine-must be kept clean with quality products and regular service.

Preventing equipment damage through contamination involves the fuel supplier, the fuel filter manufacturer, and the end user-with the end user having the primary responsibility. Filters are responsible for capturing unwanted contaminants in fuel. When left in an engine too long, contaminants can cause serious damage to the injection system. And although contaminants originate from many sources, water is the most common cause of fuel contamination problems. Water's effect on diesel fuel can be serious: it reduces fuel's lubricity causing pump and injector failure.

Sediment and other particles contaminate fuel, most commonly in the form of dirt and rust. Use of an adequate fuel filter can remove a majority of sediment buildup. Filters are designed for specific applications and many systems utilize two filter types. Engine manufacturers often advise which size of fuel filter to use, with a 10 micron being the most common recommended. Often times, a more restrictive filter, such as a 5 or 2 micron, is used to help extend the life of a fuel system.

Bacteria, another common type of contaminant, are micro organisms that live in water and feed on hydrocarbons like gasoline and diesel fuel. Often referred to as "bugs," bacteria quickly grow into colonies and spread through the fuel tank. Bacteria can even be transferred from one tank to another with fuel and quickly plug the fuel filter with a black, brown or green film. Removing the water and fuel from an engine reduces bacteria's activity, but it will not eliminate micro organisms. A biocide must be used. If you suspect bacteria in your fuel, contact your fuel supplier for lab testing. Laboratories will recommend-and possibly even supply-a biocide for treatment.