In The Shop: Finicky Fuel Filters
Nov 13, 2011
Modern diesel engines, newer than model year 2005, often have hi-fi fuel filtering systems to ensure nearly pure fuel to electronic fuel injection systems. Those systems work great, provide extra power with less exhaust contamination, but can be a pain in the patoot when it comes time to change fuel filters.
Here's why: Diesel fuel delivered to the farm is filtered to 10 microns. Electronic diesel fuel injectors require fuel filtered to 2 microns. In many cases, diesel engines now have two or more fuel filters between the machine's fuel tank and the injection pump. The filters start "coarse" and get "finer" as they progress, and the final filter ahead of the pump filters to 2 or 3 microns.
The challenge when changing fuel filters is to get the correct fuel filters for your specific engine AND to get them mounted in the right place in the system. Dumb as it may sound, some manufacturers have made all their fuel filters with the same mounting base, so you can accidentally put a coarse filter where the fine filter should go, and vice versa. It sounds like a no brainer, to install filters on the system so that coarse filters are closer to the fuel tank and finer filters are close to the injection pump, but modern fuel systems are like an explosion at a spaghetti factory---fuel lines twisting and twining everywhere. It's easy to get the wrong filters in the wrong places.
The only way to know exactly what filters--and where they go--on an engine is to provide your local dealership parts person ALL the serial numbers and i.d. numbers from the engine's serial number plate. The model number of the tractor or combine is not enough--there are lots of annoying and confusing serial number breaks within model number lines. And it's not enough to provide the parts numbers off the filters being removed--the mechanic, hired man or machine owner before you may have got the wrong filters and installed them in the wrong places.
Good luck. I've come to dread ordering fuel filters on late-model diesel engines. It's almost a crap shoot, trying to get the right filters. Thank you, engineers.