Conestoga Diesel Injection


1321 Byerland church Rd.

Willow Street PA, 17584-9776

Hours: Monday through Friday 8:00AM to 5:00PM

Phone 717-806-5561  FAX 717-806-5572

Filtration Awareness

Understanding fuel filters and why they are important, and why they are not all the same.

Every filter serves an important part in the fuel, oil or air system in which it is used.  Without filters, the engines that we operate would only last a fraction of the time.  It is proven that less than 1 pound of dust is needed to completely destroy the compression in a diesel engine.  Likewise, dirt particles in fuel will destroy a fuel pump and/or injectors in short order.  This is particularly true in common rail fuel systems.  Oil filtration functions much the way the kidney does in the human body.  Oil is to an engine as blood is to a living being.  Without filtration, contamination accumulates and destroys important functional parts.  Consequently, filters are EXTREMELY important.  It is an unfortunate fact then, that most people purchase filters without knowing what they are buying, often assuming that "any filter is good enough".  This is a great myth.  Quality of filtration varies greatly between filters and manufactures, and here is why.

There are 3 numbers to consider when shopping for a filter.  These numbers are the nominal micron size, the nominal percentage, and the absolute filter rating.  Let's define these as follows.
* Nominal Micron Size - This is the smallest particle that a filter will block.
* Nominal Percentage - This is the percentage of particles that will be filtered to the nominal micron size.  
*Absolute Micron Size - This is the smallest particle that will be caught by the filter 100% of the time, or absolutely.

Let's examine some examples to see why these numbers are important.  Let's say we have a fuel filter with a nominal micron size of 10 microns.  We know that a tank full of fuel in a fuel injected vehicle is constantly being recirculated.  Consequently, any particles 10 microns in size will EVENTUALLY be caught by this filter, as long as the nominal micron percentage is not zero.  But what is it?  We would need to find that out from the filter manufacturer, as the nominal percentage and absolute micron size are not often published.  On many filters, this number is 50%.  So, what about the other 50%?  Well that is where the absolute micron size comes in.  A 10 micron filter, may have an absolute micron rating of 30.  So this means that if we have a 10 gallon tank of fuel, and we pass all the fuel from the tank through that filter one time, that the fuel when it reaches its destination will have no particle larger than 30 microns in it, and that 50% of the fuel roughly will be filtered to have no particle larger than 10 microns.

That's a real problem for fuel injection components.  For every large particle that passes through a pump and injector may well do damage to it.  Damage that over time, accumulates until parts are severely worn and loose there ability to function.  Since the fuel recirculates, larger particles may have the opportunity to pass through the fuel injection components several times before being captured by the filter at the nominal micron rating.

This is why knowing the Nominal, Percentage, and Absolute ratings of a filter is essential to allowing you to shop intelligently for filters.  Would you pay a few dollars more for a filter that will keep you from having to make repairs thousands of miles or years later than you otherwise would with a poor filter?  Of course you would.  This is why we carry Hastings brand filters.  We feel the Hastings brand has the best combination of important micron ratings, construction quality and value.  Ask us today to price you a case of filters for your application.  Our low prices are an excellent value on a quality line of filtration products.