Changing Fuel Filters: 2003 F350 Maintenance Guide

Changing the fuel filters on your 2003 F350 is a relatively simple task that can save you a lot of money on mechanic bills. It is important to change your fuel filters at least twice a year or every 10,000 miles to ensure the health of your fuel system. The process involves draining the fuel, removing the old filters, and installing new ones. You will need a few tools and supplies, such as a fuel filter kit, a bucket or tub for draining the fuel, and a few different-sized sockets and wrenches. The steps for changing the fuel filters on a 2003 F350 with a 6.0L Powerstroke engine are outlined in detail in several online forums and video tutorials.

The primary fuel filter is located under the driver's side door, on the frame rail

To change the fuel filters on a 2003 F350, you'll need to start by locating the primary fuel filter, which is situated under the driver's side door, on the frame rail. This long steel rail runs the length of the truck.

Now, to the process of changing the primary fuel filter. Place a tub or bucket beneath the fuel pump, which is located under the driver's side door, on the frame rail. Next, locate the allen plug on the side of the fuel pump. It's a small, brass plug. Using a 6mm allen wrench, remove the allen plug. Remember, righty-tighty, lefty-loosey! With the bucket in place, drain the fuel/water completely.

The next step is to use a 36mm socket to remove the large black end cap on the end of the fuel pump nearer to the engine. Note that the fuel filter will slide out along with the cap. Pull the old filter and the o-ring from the cap, and dispose of them properly. You can place the drained filter in a lidded coffee can or leak-proof plastic bag and take it to a recycling centre that accepts scrap metal.

Now, it's time to install the new primary fuel filter. Insert the new filter into the cap, and it will snap into place once seated properly. Install the supplied o-ring into position on the end cap. Insert the new filter and cap section into the fuel pump, using the 36mm socket to tighten the cap securely—torque to 19lb. per ft. Be careful not to over-tighten or cross-thread it.

Finally, reinstall the allen plug, being mindful not to strip the thread. And there you have it—you've successfully changed the primary fuel filter on your 2003 F350!

The secondary filter is located on the engine, between the CAC and air intake tubes

The secondary fuel filter is located on the engine, between the CAC tube and the air intake tube. It is situated on the driver's side of the engine, sitting just behind the primary fuel filter, which is located under the driver's side door, on the frame rail.

To replace the secondary fuel filter, first, remove the black top cap using a 24mm socket or 1/2" square drive ratchet. Then, take out the fuel filter from its housing and remove the o-ring from the lid. Drain any excess fuel from the housing using a turkey baster and remember to dispose of it properly. Insert the new secondary filter into the housing and install a new o-ring onto the lid. Finally, reinstall the black top cap, torquing the bolt to 124lb. per in. (or approximately 10-11lb. per ft.) with the 24mm socket or 1/2" square drive ratchet.

It is important to note that replacing the fuel filters is vital upkeep and should be done at least twice a year or every 10,000 miles to maintain the health of the fuel system. Additionally, after replacing the filters, you must prime the fuel system and bleed out any air by turning the ignition to the Run position for 30 seconds, repeating this process three times.

You will need a fuel filter kit, a bucket or tub, and a leak-proof container

To change the fuel filter on a 2003 F350, you will need a fuel filter kit, a bucket or tub, and a leak-proof container. The fuel filter kit should include a new primary and secondary fuel filter, as well as a new o-ring. The bucket or tub will be used to drain the fuel, and the leak-proof container will be used to transport the old filter for disposal.

It is important to note that you should only use Motorcraft fuel filters or Racor replacement fuel filters for your F350. In addition to the fuel filter kit, bucket or tub, and leak-proof container, you will also need the following tools: a 36mm socket, a 6mm Allen wrench, and a 24mm sock or 1/2" drive ratchet.

• Place the bucket or tub beneath the fuel pump, which is located under the driver's door on the frame rail.
• Locate the allen plug on the side of the fuel pump. It is a small, brass plug.
• Using the 6mm Allen wrench, remove the allen plug.
• Drain the fuel/water completely into the bucket or tub.
• Using the 36mm socket, remove the large black end cap on the end of the fuel pump that is nearer to the engine. The fuel filter will slide out along with the cap.
• Pull the old filter and the o-ring from the cap and properly dispose of both. You can place the old filter in a leak-proof container, such as a lidded coffee can or leak-proof plastic bag, and take it to a recycling center that accepts scrap metal.
• Install the new primary fuel filter into the cap. The new filter will snap into place once seated properly.
• Install the new o-ring into position on the end cap.
• Insert the new filter and cap section into the fuel pump, using the 36mm socket to tighten the cap securely to 19lb. per ft.
• Reinstall the allen plug, being mindful not to over-tighten or cross-thread it.

To change the secondary fuel filter, follow these steps:

• Using the 24mm socket or 1/2" square drive ratchet, remove the black top cap.
• Remove the fuel filter from the housing and the o-ring from the lid.
• Drain the excess fuel from the housing using a turkey baster. Properly dispose of the fuel.
• Insert the new secondary filter into the housing.
• Install the new o-ring onto the lid.
• Reinstall the black top cap, using the 24mm socket or 1/2" square drive ratchet to torque the bolt to 124lb. per in. (or approximately 10-11lb. per ft.).

Once you have replaced both fuel filters, you need to prime the fuel system and bleed out any air before starting the vehicle. Turn the ignition to the Run position three separate times for 30 seconds each time. Failure to properly prime the fuel system can cause serious damage to the injectors.

Use a 36mm socket and 6mm Allen wrench to remove the fuel filters

To remove the fuel filters from your 2003 F350, you'll need a 36mm socket and a 6mm Allen wrench.

First, locate the fuel pump under the driver's side door, on the frame rail. Place a bucket or tub beneath it to catch any fuel or water. Now, on the side of the fuel pump, you'll see a small, brass allen plug. Using the 6mm Allen wrench, remove this plug. Ensure the bucket is directly underneath to catch any fuel or water that drains out.

Next, using the 36mm socket, remove the large black end cap nearest the engine. The fuel filter will slide out along with the cap. Pull the old filter and the o-ring from the cap and dispose of them properly.

Now you're ready to install the new primary fuel filter. Insert it into the cap and install the supplied o-ring into position. Then, insert the new filter and cap section into the fuel pump, using the 36mm socket to tighten the cap securely—torque to 19lb. per ft. Finally, reinstall the allen plug, being mindful not to over-tighten or cross-thread it.

Dispose of the old filters properly and install the new ones, along with new O-rings

Once you have removed the old fuel filter, you will need to dispose of it properly. Start by draining the filter for a full 24 hours. After this, you can place the filter in a lidded coffee can or a leak-proof plastic bag. Then, take it to a recycling centre that accepts scrap metal.

For the remaining fuel, you can wait until you change your oil and dump the fuel in with the used oil. Alternatively, you can take it to an auto parts store or anywhere that recycles oil.

Now, you can install the new fuel filter. Insert the new filter into the cap and it will snap into place. Then, install the new O-ring into position on the end cap. Finally, insert the new filter and cap section into the fuel pump, tightening the cap with a 36mm socket.

It is important to note that you should not over-tighten or cross-thread the cap. After you have installed the new filter, you must prime the fuel system and bleed out any air by turning the ignition to the Run position for 30 seconds, repeating this process three times.

Frequently asked questions