The fuel filter’s main purpose is to clean the fuel of the dirt and debris which damages the diesel fuel pumps, injectors and nozzles. Damage to these components and others, can lead to poor starting, higher fuel consumption, reduced engine power and component failure.
The fuel filter’s secondary, and almost as important, role is as a water separator. Fuel contaminated by water causes poor fuel burn, reduced power and corrosion of components such as the injectors and fuel pumps, which also leads to poor engine performance. Fuel injector wear is the top reason for early replacement and effective fuel filtration is the best way to prevent wear.
A typical fuel system returns the unused fuel back into the tank, meaning the fuel filter constantly has fuel cycled through it. A fuel filter passes about 1.5 litres of fuel per minute and circulates 45,000 litres of fuel every 500 hours of operation