If there is one thing that your fleet shop may not be considering enough, it is fuel filtration. Supplemental fuel processers include several different components, from a fuel filter to a water separator and heater. They are designed to save several components of your fuel system from damage, whether it be from long use, extreme cold, or extreme heat. Yet, too few yard shops put enough thought into their vehicles’ fuel filtration systems.
Ask yourself this question: Is there any value to putting an engine worth tens of thousands of dollars at risk just because you aren’t paying enough attention to your fuel filter? No. Too few technicians take this important matter into account, but that doesn’t mean it is a matter of willful negligence. They may not understand the need to the application.
It isn’t always clear when a fuel filter is not doing its job. It seems like a simple matter of putting a fuel filter on, changing it, and then if nothing goes wrong, changing it again later. The important thing to consider is that even if it seems like nothing has gone wrong, there could be problems lurking underneath he hood that you simply aren’t aware of.
Very few fleets cut open a fuel filter to see if there is anything amiss. Even if you did cut it open, it is very likely you would not see anything immediately alarming. Only if you are facing a serious fuel problem would you see gunk or problems. If it seems like your fuel filters are not lasting as long – or performing as well – as they should, it may be time to consider other problems.
It May Not Be the Filter
There are several reasons why you may be having problems with your vehicles that you assume are related to the fuel filter itself, when they are not. Such things as variability in fuel quality, excessive fuel contaminants, improper additive use or additive leakage, or even biodiesel production leftovers can cause problems that you may assume are related to a bad or poor performing fuel filter.
If you do cut open a fuel filter and see these types of things inside of it, it may be a sign that the fuel filter is doing its job. Fuel filters are intended to remove particulate matter and recycle the fuel within the system. It has a holding capacity and efficiency level only governed by the specification of the filter.
Problems arise when high-pressure fuel systems built into modern commercial motor vehicles comes into play. There are extremely close internal tolerances at play, and they rarely respond well to contaminated fuel. Consider the numbers.
An average gallon of fuel pumped from today’s stations can contain over 17 million potentially harmful particles. Over time, these particles can wear down critical components of the vehicle’s engine. Where you think the problem is the filter, it may actually be the fuel.
Modern Filters to the Rescue
Fuel filter manufacturers have been answering the call to design products specifically designed to address these problems. Fuel filter efficiencies have risen to such an amount that they can now effectively filter out particles down to the 4-micron size. These particles are far too small for the eye to see, but they can still harm engine components if not effectively filtered out.
As an example, if 90,000 4-micron size particles enter the fuel filter and even over 1,000 get through that fuel filter’s efficiency rate is only 98%. While that isn’t terrible and is pretty much on par with fuel filters of a prior generation, it doesn’t quite do the job that modern fuel filters are capable of. Today’s Nano-based fuel filters of today can remove 4-micron sized particles up to 99.9% of the time.
What does this mean? For every 90,000 particles making their way through the filter, only 200 get through the filtering substrate. Even small percentage improvements represent filtration advantages of orders of magnitude. A one percent improvement represents 10 times the filtration power of previous generations.
High performance filtration systems do an even better job because they incorporate multiple layers of media to get the job done. They provide both a high-performance efficiency and long life. While previous versions of fuel filters used cellulose as the primary substrate method, newer, high-performance filters use everything from micro-glass to single-layer media composed of advanced nano-filters that work in stages. They can catch and store both large, small, hard, or soft particles, no matter the source or size.
But does that mean that modern sources of filtration come without problems? Of course not, filters are subject to everything from vibration to changes in both flow, temperature and pressure. Nor are all filters the same, so it is important to understand what makes a filter get the job done and in what ways it is susceptible to changes or failure.
How Water Created Filtration Problems
If there is one thing that fuel cannot stand, it is the presence of water. It is water within the fuel system that you must worry about when evaluating these situations. Water cannot be compressed in the same way diesel fuel can, which creates problems for both fuel pumps and injectors. Failures occur when there is too much moisture in the lines.
In fact, when it comes to problems for fuel injectors and the entire system, water can be more of an issue than contaminants found within the fuel. That is why it is important that a fuel filter with a media that can filter out water is critical to the proper functioning of the filter and entire system. Many modern filters are designed to strip out water, but it is still important that your fleet technician double checks before committing to specific system.
Fuel filters work to separate water by containing tiny particles that trap the water within the filter then filter it down to a glass bowl where it can be drained out of the system. Other types of filters have internal mechanisms for separating out water, so sensitive that you cannot even see how the process works, which is okay as along as it is doing the job of filtering out the water.
It is important not to succumb to the belief that water can’t be trapped within your fuel system. There are so many ways water can be picked up and trapped within your fuel system, whether it be from a supplier’s tanks to high levels of humidity. It may even be a good idea to have your shop technicians get into the habit of draining water from the fuel tanks on a semi-regular basis. There are fuel kits and other systems that help in this endeavor.
Keeping Other Fuel Types in Mind
With the proliferation of biodiesel and other synthetic fuel blends out there today, it is important to consider these fuel types when selecting your fuel filter. Biodiesel and other fuel blends put more pressure on filtration systems. Glycerin and other types of glycerol are byproducts of biodiesel production and while they remain warm and in liquid form, they will not cause any problems for your filter or filtration system.
Where you must be careful is when the temperature drops. At low temperatures, glycerin turns into a waxy substance that can sink to the bottom of a tank and get stuck in the filter. This in turn can result in a corrosive effect on the engine through unwanted engine deposits. Left unchecked, these can disable a vehicle and result in an unwanted “Out of Service” notice sent to your shop.
There are several factors that impact whether biodiesel blends can create problems such as the blend percentage, moisture, and glycerin content. A fuel solution can only hold so much glycerin. It is important to ensure the glycerin does not separate out from the fuel mixture itself, lest you find yourself in an unwanted situation.
A Final Word on Additives
Diesel fuel additives are not always the best solution and can cause problems in and of themselves. If you are going to choose a fuel additive, make sure you are well aware of how that additive may interact with your fuel system.
Make sure the results of the additives you choose are well documented, proven, and are shown to work with the vehicle and fuel type you currently employ. Additive results are easily measurable and can be procured from the manufacturer of the additive.
And just as with the fuel filter itself, even if it seems like it is working, you must check to make sure it is doing as it says. Just because you aren’t getting gunk or unwanted gel doesn’t mean you have nothing to worry about.
Whether you are a maintenance manager or shop technician, don’t let the absence of an obvious problem lull you into believing there isn’t want. Always check your fuel filter, ensure the additives you use are compatible and keep moisture out of the system. By doing so, you can keep unwanted downtime at bay.