Clean fuel takes on increased importance in today's low emission heavy duty trucks

In order to meet increasingly tight emissions regulations in the heavy duty truck market, injection pressures as high as 30,000 psi are becoming increasingly common.  Tolerances and clearances in the injection pump and injectors are becoming smaller and smaller as a results, making fuel cleanliness increasingly important.

FUEL FILTRATION

Fuel filtration is taking on an important role in the quest for cleaner fuel.  According to WIX senior technical services manager Chris Greeson, everyone in the industry is seeking improved fuel filtration, but few realize that increased efficiency often comes at the expense of capacity.  The more contaminants the fuel filter catches, the quicker the media fills up and requires changing.  Larger fuel filters constructed with efficient synthetic media are effective in order to capture more contaminants and counter shorter change intervals.

CHANGE INTERVALS

It is important to change fuel filters befoe they plug and impact driveability.  Dirty fuel and cold weather operation can often plug filters quicker than normal.  "When I was in the field as filter salesperson, I carried extra fuel filters with me in my company car," says Greeson.  "When the weather got cold, I gave a lot of them away on the side of the road.  I was surprised at how many over-the-road trucks don't carry extra fuel filters with them."

According to FleetNet America, fuel filters are one of the top 10 reasons trucks require breakdown service.  Fleet drivers can save both time and money by carrying extra fuel filters with them on the road.

Opening used filters and looking at the subassembly can provide valuable clues regarding the quality of the fuel used and filter change intervals.  A black and oily subassembly reveals poor fuel quality and too long a change interval, while red sludge indicates a rusty fuel tank.  Used filters should be dark, with no obvious signs of contaminant build-up.

COLD WEATHER

When the weather turns cold, water in diesel fuel forms ice crystals and causes filter plugging.  Often, this problem is misdiagnosed as fuel gelling (wax crystal formation), which generally occurs at colder temperatures than ice formation.  To diagnose the problem, remove and drain the filter and place it on a piece of filter paper or blotter that will absorb the fuel.  If the blotter gets wet as the filter warms up, ice crystals were the source of the problem.  If it's a wax problem, the wax will remain in the filter.

To avoid cold weather problems, be sure water is drained from the saddle tanks and fuel delivery system before cold weather sets in.  AMSOIL Diesel Fuel Additive Concentrate can be used to combat fuel gelling problems, lowering gel points by 20 to 35 degrees F.

CLEANLINESS

Contaminants often enter fuel systems during routine maintenance such as changing fuel filters, fuel lines and injectors.  In order to avoid such contamination, it is important to work in a clean environment and clean parts and their surrounding areas before removing filters or parts.  Because rags and shop towels can leave behind lint and fibers, compressed air is a better choice for drying and cleaning parts.

CLEAN FUEL

According to Matt Stein, lead engineer for engine liquid filtration at Donaldson, people commonly blame plugged fuel filters on the filters themselves, rather than the fuel quality.  Fuel should be purchased from reputable suppliers who keep clean facilities and have reasonably high fuel turnover.  If a facility looks dirty or if it doesn't look like the pump filters get changed on a regular basis, there's a good chance the fuel is dirty.  For those who keep their own fuel supply, it is important to have a filter on the dispensing unit before it enters the truck.  Drivers should also be certain the saddle tank is free of contaminants that could enter the tank while fueling.

AMSOIL carries the full line of premium Donaldson replacement fuel filters, featuring the latest advances in filter media that make the difference between engine power and engine problems.