Changing The Fuel Filter On Your F250 Diesel: Step-By-Step Guide

Changing the fuel filter on a Ford F-250 diesel engine can improve the truck's engine performance, speed, and gas mileage. The process involves five steps: accessing the fuel filter housing, draining the fuel in the housing, removing the old fuel filter, installing the new fuel filter, and testing for any leaks. The tools required include a 13mm socket and ratchet, a strap wrench or large channel lock pliers, a hose, a container for the drained fuel, and a drip pan. The process is relatively similar for F-250s from 1999 to 2019, with some variations depending on the model year.

Access the fuel filter housing

To access the fuel filter housing of your F250 Super Duty, start by parking on a level surface and opening the hood. Use a 13mm socket and ratchet to remove the two 13mm nuts securing the engine cover. Remove the cover so you can access the fuel filter housing underneath.

The fuel filter housing is located under the truck, behind the front passenger tire. This is where you will find the drain tube to which you will connect a hose to drain the fuel in the housing.

Before you drain the fuel, you will need to access the drain release lever on the backside of the fuel filter housing. Turn the lever clockwise to release the fuel.

Now that you have accessed the fuel filter housing and know where to find the drain tube and release lever, you can proceed to the next steps of draining the fuel and removing the old fuel filter.

Remember to refer to your F250's owner's manual for specific instructions and safety precautions before attempting any repairs or maintenance.

Drain the fuel in the housing

To drain the fuel in the housing of your F250 Super Duty, follow these steps:

Firstly, park your car on a level surface and open the hood. Locate the fuel filter housing drain, which can be found under the truck, behind the front passenger-side tire. Connect one end of a hose to the drain tube and place the other end in a container that can hold at least 16 ounces and is safe for catching fuel. Make sure you have a container that is large enough and appropriate for the job, as spilling fuel can be dangerous and messy.

Now, turn your attention to the backside of the fuel filter housing, where you will find a drain release lever. Turn this lever in a clockwise direction to release the fuel. You should see the fuel flow through the hose and into your container. Once the fuel has been fully drained, turn the lever anti-clockwise to close the drain.

Remove the hose and fuel drain container, and you're done! Remember to check your local laws for instructions on how to safely dispose of the fuel. Additionally, loosen the fuel filter housing about 3 turns prior to draining to keep additional fuel from entering the housing and minimise fuel waste.

Remove the old fuel filter

Before starting, park your F250 on a level surface and open the hood.

To access the fuel filter housing, use a 13mm socket and ratchet to remove the two 13mm nuts securing the engine cover. Then, remove the cover.

Next, drain the fuel in the housing. Connect one end of a hose to the drain tube under the truck behind the front passenger tire, and place the other end in a container that can hold at least 16 ounces of fuel. Turn the drain release lever on the back side of the fuel filter housing clockwise to release the fuel.

Once the fuel has been drained, relieve the pressure by loosening the fuel filter cap with a strap wrench or pliers. Position the tool's jaws in the notches of the cap. Then, remove the fuel filter cap and filter. Place the filter in a drip pan to catch any excess fuel. Depending on the type of fuel filter, the fuel filter and cap might be one or two pieces. If they are separate, be sure to save the cap in case you need it for the new filter.

After the fuel has drained, close the drain lever and remove the hose and fuel drain container.

Loosen the fuel filter housing about 3 turns prior to draining it to keep additional fuel from entering the housing when draining and to keep fuel waste to a minimum.

Install the new fuel filter

To install the new fuel filter, first, coat the smaller O-ring with diesel fuel. The new fuel filter should come with new O-rings, so make sure they’re included. Lubricating the O-rings can help keep them from sticking to the housing and make them easier to remove during the next filter change. Install the smaller O-ring on the plastic part of the filter. Next, coat the larger, beveled O-ring with diesel fuel and set it around the fuel filter housing. Install the new fuel filter into the housing and screw down the fuel filter cap. If the fuel filter and cap are one piece, keep the cap in case you need it in the future.

Test for leaks

To test for leaks in your F250 diesel's fuel system, there are a number of steps you can take. Firstly, if you suspect a leak in the high-pressure fuel system, you should steam clean the entire fuel system before inspecting for leaks. Then, start the engine and let it run until it reaches an operating temperature of 140°F (60°C). If you notice any signs of external leakage, replace the O-ring.

Next, perform the RPBO test. If this test fails, turn off the engine and inspect the high-pressure pump to rail feed fittings at the rail and the pump for leakage. If you find any leaks or loose line fittings, torque the line fittings, restart the engine, and recheck. If leaks are still present, replace the lines.

If there are no leaks, inspect the injector fuel line rail connections for external leaks. Again, if you find any leaks or loose lines, turn off the engine, torque the fuel line rail connections, restart, and recheck. If leaks persist, replace the lines.

The next step is to inspect the Fuel Rail Pressure Sensor for leakage. If the sensor is leaking or loose, turn off the engine, torque the sensor, restart, and recheck. If leaks persist, replace the sensor.

After this, inspect the PLV connection for leakage. If the PLV is leaking or loose, turn off the engine, torque the PLV connection, restart, and recheck. If leaks are still present, replace the PLV connection.

The final step is to inspect the high-pressure fuel pump for external leaks. If there are leaks coming from the high-pressure pump, turn off the engine and replace the pump.

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