What Happens to the Fuel Filter

Abrasive contaminants are literally everywhere in the environment. Some, like small metal particles, grinding swarf and paint residues may be introduced or left in the engine when it’s assembled. That’s why it’s a good idea to ask engine manufacturers about their assembly plant. And there contamination control programs when you’re comparing vendors.

Fuel and lubricants are another often overlooked source of contamination. Water, either dissolved or in solution, is a serious concern with stored diesel fuel. Dirt and other particulates from many sources, including airborne dirt and dust that enter tanks through vents and breathers. Are almost certainly present in any stored fuels and lubricants.

They may be clean when they leave the refinery. But it’s extremely likely that they aren’t clean at the point of use on industrial and construction sites. At that point, they have probably passed through pipelines, been delivered by trucks. Then stored in on-site tanks and flowed through pumps, hoses, nozzles, and any number of other devices before getting into the engine.

Of course, the air itself is far from clean in most of the places a diesel engine works. Dust and dirt are a commonplace on construction job sites, farms, and even stationary engine locations.

Even the engine itself is a source of contaminants. Bearings, crankshafts, pistons and other moving parts release microscopic metal particles as part of normal operating wear. Dust enters through worn seals and broken breathers. And, even maintenance parts like new filters can introduce contaminants. If they aren’t left in the original protective packaging until installed.