When To Replace Diesel Fuel Filter?

When it comes to owning or maintaining a diesel vehicle, it’s crucial to understand how the engine technology differs from that of gasoline-powered automobiles. The changes have a substantial impact on normal diesel engine maintenance, such as what oil to use and how often filters – particularly oil filters, air filters, and fuel filters – are changed. Because diesel fuel is dirty by nature, it’s no surprise that the fuel filter is one of the most vital filters on any diesel engine. They typically need to be replaced every 10,000 to 15,000 miles, but a modern gasoline fuel filter can last 100K miles or more before needing to be replaced – if at all.

Most diesel truck applications will necessitate the replacement of two diesel fuel filters. The first is a pre-filter, which is located between the gasoline tank and the fuel pump — commonly along the frame rail on the undercarriage. This filter removes any impurities from the fuel before it reaches the pump. The secondary filter is normally found beneath the hood in the engine compartment, and its job is to clean the fuel further before it reaches the injectors.

The following is a highly generalized breakdown of how to change a diesel fuel filter on a heavy-duty diesel truck successfully. Some aspects may alter significantly based on your application, and we strongly advise you to check the vehicle’s maintenance handbook for any inconsistencies.

1. If necessary, lift the truck off the ground to gain greater clearance.

2. Before doing this service, make sure the engine is turned off.

TIP: Changing a gasoline filter can be a dirty process. Place a large enough drain pan behind the filter to reduce the chance for a mess.

3. Remove a drain plug from the filter housing next. To loosen it up, you’ll probably need a hex tool or an allen wrench.

4. Drain the petrol from the fuel line and the filter housing.

5. After the fuel has drained into the pan, loosen the filter cap and remove it from the housing with a ratchet and socket.

6. The filthy fuel filter may or may not come out of the housing still attached to the cap. Remove it and dispose of it properly.

7. Next, remove the filter cap’s old O-ring. Using a pry tool or a flathead screwdriver may make it easier to remove.

8. Wipe down the filter cap and the housing’s sealing surface thoroughly. After that, put the O-ring that came with the new filter in place.

An poorly placed cap O-ring is one of the most common causes of diesel fuel filter leaks. As a result, make sure the replacement O-ring is positioned properly against the ridge all the way around the cap.

9. After that, replace the old filter in the clean filter cap. It should click into place and stay put.

10. Finally, tighten the cap to the manufacturer’s requirements with a torque wrench. – Don’t forget to replace the drain stopper!

11. To release the cap on the second filter, which is normally found under the hood, you’ll need a square drive or socket.

12. Remove the cap by hand after it has been loosened, and then pull the dirty filter out of the housing.

TIP: To avoid a major mess, lift the cap slowly with the filthy filter still inside and keep it there for a minute to allow the petrol to drain back into the housing.

13. Wipe off the filter cap and sealing surface on the housing with a damp cloth, just as you did with the filter underneath the truck. Wipe down both the inside and outside of the cap, as well as the thread surface.

14. To remove the old O-ring from the cap, you’ll need to use a pry tool or a flathead screwdriver once more.

15. Just as you did with the other filter’s O-ring, ensure sure the new one is correctly positioned against the ridge all the way around the cap. When the cap is reinstalled, this will ensure that there are no leaks.

16. Replace the filter in the housing and hand-tighten the cap. Remember that fuel filter leaks can occur whether the cap is overtightened or undertightened, so use a torque wrench to finish tightening the cap to the manufacturer’s requirements.

You should bleed any air bubbles and prime the fuel system before driving the truck. This entails purging the system of any air that may have gotten in while the filter caps were removed and ensuring that the fuel system only contains diesel fuel. It’s a crucial step in preventing vapor lock, which occurs when liquid fuel is transformed to gas vapor before reaching the fuel rail. The procedure for priming diesel fuel varies from vehicle to vehicle, so consult your owner’s manual for specific instructions.

As previously said, diesel fuel is a naturally dirty fuel, therefore changing the diesel fuel filter on a regular basis is crucial to the engine’s best efficiency and longevity. The majority of diesel truck owners utilize their vehicles for important duties including towing, transporting, and plowing. For these drivers, the effects of a clogged diesel fuel filter can be very inconvenient, such as loss of power when driving uphill or when the engine is under heavy strain, such as when towing or moving large items.

If you’d like to see a visual illustration, check out this video of a 2017-2019 F250 Powerstroke diesel fuel filter change.

How do I know if my diesel fuel filter is bad?

The signs of a clogged diesel fuel filter can be seen in how the diesel engine starts and runs. When a diesel fuel filter becomes clogged, the engine will likely begin to idle rough and sound as if it is about to stall. This is especially true when the weather is chilly. Because there isn’t enough fuel getting into the engine’s fuel injectors, the engine may sound like it’s choking once it’s warmed up. A clogged diesel fuel filter can also cause engine sputtering, or losing out during acceleration. In this case, the filter has accumulated too much dirt and debris and is preventing enough gasoline from reaching the engine’s combustion chamber. Finally, whether or not an engine will start depends on how clogged the filter is. This means the engine turns over but does not start, acting as if it is out of gas despite the fact that there is plenty of gas in the tank.

What happens if you dont change diesel fuel filter?

What Happens if the Fuel Filter Isn’t Replaced? The car may encounter the following symptoms if there are issues with the fuel system, such as a clogged fuel filter: Misfiring occurs when one of the phases in the combustion process is missed by the engine. Misfiring causes the engine to shake, buck, or run rough.

How do I know if I need to change my fuel filter?

5 Signs That Your Fuel Filter Needs to Be Replaced

  • The car is having trouble starting. This could indicate that your filter is half clogged and on the verge of becoming entirely blocked.

How often do fuel filters need to be replaced?

Your air filter should be replaced every 12,000-15,000 miles, according to most manufacturers. Because the average American drives 13,000 miles each year, changing the air filter once a year is usually the best practice. This is a simple task that may be done in conjunction with any other annual auto maintenance, such as installing winter tires or spring cleaning.

How Often to Change Fuel Filters

Fuel filters are a little more difficult to work with than air filters. Depending on the age of your vehicle, the fuel filter may need to be replaced every 20,000-30,000 miles, which, given the typical American driving distance of 13,000 miles per year, is around once every year and a half to two years. Fuel filters in contemporary automobiles, on the other hand, can last up to 60,000 miles. The suggested mileage for your vehicle’s fuel filter may be found in the owner’s manual, and we strongly advise you to consult it to determine how often it should be replaced.

How often should diesel oil be changed?

Oil changes for diesel pickups are usually recommended every 5,000-7,000 miles or every six months on cars that pull moderately. You might be able to go much longer if you don’t tow or don’t tow very often.

Can you change fuel filter with full tank?

Dane from the Heights Four Seasons MasterLube teaches how to install a fuel filter.

A high-pressure canister filled with filtering medium is the conventional fuel filter for most fuel-injected vehicles. Clamped, threaded, or customized fittings may be used on filters to ensure a secure connection to the gasoline system. Filters for carbureted engines can be found at the carburetor’s inlet or inline. Carbureted engine filters do not have to bear the same pressures as fuel-injected engine filters.

Fuel filters are designed to catch dangerous pollutants that might create problems with carburetors and complex fuel injectors. Carbureted engines use fuel filters to purify the fuel before it enters the float bowl. When the fuel pump is turned on, however, injection filters purify the fuel (unless the fuel injection system is a returnless design). Fuel flows constantly from the supply side to the fuel rail or throttle body, passing through the filter. The fuel that does not make it into the engine is returned to the tank, and the cycle begins again. With a full tank of gas, the filter may clean the whole volume of fuel in the tank several times before it is used up.

Replacement of the filter in carbureted autos should be done once a year. Some carmakers recommend not replacing the gasoline filter at all during the first 100,000 miles of “normal” driving on automobiles with fuel injection. Because normal driving usually entails intense driving due to less-than-ideal conditions, the filter should be replaced every year or 15,000 miles. A clogged filter might restrict gasoline flow from your car’s electric fuel pump, reducing its life expectancy. Filter changes on a regular basis eliminate any concerns about the filter causing future issues. On domestic automobiles and trucks, most filters are hidden beneath the frame or body. Imports, on the other hand, are the polar opposite. Their filters are normally stored in the engine compartment. Be cautious if you decide to alter the filter yourself. Fuel injection systems keep pressure in the lines, which must be released before the filter can be replaced. Keep in mind that gasoline is highly combustible. The methods for releasing pressure differ. Furthermore, replacing some fuel filters necessitates the use of specialized gear. It’s preferable to have your car’s fuel filter updated by a skilled service expert because of these technicalities and most filter locations.

Does changing fuel filter improve performance?

The gasoline filter prevents dirt and debris from entering the fuel delivery system’s critical components. As a result, the engine’s performance improves. Maintenance and replacement of the gasoline filter according to the manufacturer’s recommendations can improve the performance of your vehicle by 2% to 4%.

Can a diesel fuel filter be cleaned?

As your engine runs, the fuel pump draws fuel from the tank through pipes and injectors until it reaches the combustion chamber, where it is ignited. It’s a voyage that’s been meticulously timed and metered, with tight tolerances, intense heat, pressure, and friction. A gasoline filter serves a crucial function that cannot be overstated, and it, like any other filter, isn’t supposed to endure indefinitely. It will become filthy at some point and will need to be dealt with. So, what’s next?

Purpose of a Fuel Filter

Gasoline filters are used in fuel systems to remove and keep out contaminants such as debris that may enter during the filling process or rust that accumulates due to moisture inside steel components.

Because of the aforementioned tight clearances and high pressures, even minute particles can wear out and damage system components, resulting in leaks, reduced performance, premature failure, and costly repairs. Particulate matter is trapped and held in fuel filters, which protects against this. Most filter elements are constructed of treated paper and are classified according to the size of particles that can flow through them. Microns are used to measure these ratings. The filter element in the outer casing is frequently pleated to increase surface area and thus allow for more fuel flow as the engine requires.

Signs of Clogging

Unfortunately, when a filter becomes blocked and unclean, it contributes to the problem. A blocked filter can manifest itself in a variety of ways, but it all boils down to the dirty filter impeding fuel flow and depriving the engine of the oxygen it need to burn.

You may notice that the vehicle is difficult to start, idles rough, or accelerates slowly. In contrast, you may find that when you slow down to a stop, the engine struggles or dies. If the situation is dire, the engine may run out of fuel while driving or fail to start at all. You may also notice misfires and a general loss of performance, but many of these symptoms could be caused by other problems, so if you’re not sure how to identify a clogged filter definitively, pull codes with an OBDII scanner or chat with a specialist.


The answer is a loud no if you want to remove a fuel filter and then clean it by rinsing or blowing it out before reinstalling it. Paper-element filters are designed to be replaced rather than reused, and using the incorrect fluid or air pressure might harm them or cause particles to lodge farther inside. Some fuel filters have metal elements that require special cleaning, and some diesel filters are bowl-type, which means they collect water and must be drained, but the vast majority of fuel filters simply need to be replaced when their service life is finished.

The lifespan of a filter is determined by the manufacturer’s recommendations, but if your car is older or consumes a lot of fuel, you’ll want to replace it more frequently. Fuel filters are a crucial component of engine maintenance, and they’re extremely simple to maintain. Replace them before they have an impact on performance or necessitate more extensive repairs.

NAPA Online has a comprehensive list of filters, or visit one of our 17,000 NAPA AutoCare facilities for routine maintenance and repairs. Chat with a qualified professional at your local NAPA AUTO PARTS shop for more information on changing a gasoline filter.