Dirt and Dust Can Ruin Your Engine
Your engine life can be reduced by 50% with dirt and dust in your fuel system.

Problems Caused by Dirt and Dust
More than 85% of fuel system failures are caused by dirt and dust in the fuel.
The smallest particles of dirt and dust can accelerate deterioration of engine parts by introducing tiny obstructions into finely tuned engine processes streamlined for fuel efficiency and stringent emission controls.
Any engine can be damaged by dirt and dust in the fuel. The newer Tier 2 and Tier 3 engines are even more vulnerable to damage, because they have a higher fuel injection pressure, causing dirt and dust to act as abrasives.

How Dirt and Dust Enter the Fuel Line
When Fueling
When Operating in Dusty Environments
When Servicing Equipment

Damage from Dirt and Dust
There are two areas where microscopic particles of dirt and dust can cause disastrous damage your engine.
Injector Barrel and Plunger Interface
There is a fluid interface of just 2.5 microns between the injector barrel and plunger needed to maintain quick and smooth continuous movements. Dirt and dust will interfere with this movement.
Control Valves
Control valves in the fuel system maintain fuel pressure. When dirt and dust are introduced, the valves could start to leak, causing engine power to decrease.
Any area where quick, sliding movements are critical to engine function can become worn and unable to slide easily due to dust and dirt in the fuel—parts like inner and outer valves, nozzle needles and seats and command piston sliding portions.

Preventing Dirt and Dust from Entering the Fuel Line
Our Two Filter System Helps Prevent Contamination
With Komatsu’s two filter system—a main fuel filter and a pre fuel filter—you have twice the protection against contaminants entering the fuel system. The main fuel filter screens particles as small as 2 microns (the size of bacteria). The pre fuel filter screens particles that are at least 10 microns (slightly larger than a red blood cell). The risk of contamination still exists, however.
Change Filters When Necessary*
Follow Directions for Changing Filters*
Use Correct Filters
Use genuine Komatsu filters. Imitation filters may not screen particles as effectively.

*Refer to the Operation and Maintenance Manual for specific procedures for changing filters and for recommended replacement intervals. Both may vary with the machine model.