Double Check Fuel Filters

Published on: 11:28AM Feb 15, 2009
 Long story short: It is very easy to get the wrong diesel fuel filters installed in the wrong places on late-model farm equipment. At a minimum, using the wrong filter in the wrong place will shorten the time before the filter begins to clog, you notice a decrease in power, and have to replace the filter. Worst case scenario, the wrong filter in the wrong place can allow dirt or water to damage the engine's computerized unit fuel injectors, which can cost more than $1000 each to replace.

Some new combines, tractors, cotton pickers and other large self-propelled machines have up to three separate diesel fuel filters. Each has a different job and must be installed in the correct location. In a perfect world, each would have a unique filter base to ensure that only the correct filter would fit. That is not the case--water separator filters sometimes happily screw into the base designed for 2-micron final filters. In a perfect world, every engine would have just one set of fuel filters. In the real world, each model of engine can have a half-dozen serial number breaks, and each serial number break can call for a different set of filters.

So when it comes time to change diesel fuel filters on engines newer than 2003 or 2004, be very, very conscientious about getting the right filters and installing them in the correct locations. Many filters come marked with their filtering capacity, measured in microns. Make sure that filtering media gets "tighter" from fuel tank to engine, and from engine to injection pump. A 10-micron filter should always be upstream (ahead) of a 2-micron filter because the 10-micron filter is more coarse than the 2-micron filter. Many 2-micron filters carry the label, "final filter," meaning the filter is designed to be the final filter before fuel enters the injection pump.

It sounds like a simple thing, to get the correct filters installed in the right places. But in the past month we've dealt with three or four combines in our shop that had 10 micron filters installed where there should have been 2 micron filters, and water separator filters installed in place of 10 micron filters. So far, nobody has had to replace damaged injectors or injection pumps, but at the rate and frequency we're seeing misplaced filters, it's only a matter of time.