Changing Fuel Filter In 2006 Duramax: Step-By-Step Guide

Changing the fuel filter on a 2006 Duramax is a straightforward process that can be done in a few simple steps. First, you'll need to gather the necessary tools and materials, including a panel clip remover, a Water In Fuel sensor wrench (or channel locks), a 1/2 inch Nut driver, and some 2-stroke oil to lubricate the o-rings. Next, you'll want to remove the inner fender well liner by taking out the pins that secure it to the truck. With the liner removed, you can now access the fuel filter. Disconnect the WIF connector and unscrew the fuel filter, making sure to keep it upright to avoid spilling any fuel. Drain the old filter and remove the WIF sensor, replacing the old o-rings with the new ones that come with the new fuel filter. Lubricate the new o-rings with engine oil, then install the new fuel filter, making sure not to overtighten it. Now, locate the bleed valve on the driver's side of the fuel priming pump and open it. Pump the plunger on the fuel filter housing until diesel fuel begins to flow out of the bleed valve. Tighten the bleed valve, clean up any spills, and reinstall the inner fender liner. Finally, start the engine and check for any leaks.

Removing the inner fender well liner

To remove the inner fender well liner of your 2006 Duramax, you will need a panel clip remover. This can be purchased at a local auto parts store.

Once you have the tool, sit by the passenger-side tire and look at the fender well. Using the panel clip remover, remove the pins holding the inner fender well liner to the truck. Be sure to also pull out all the wire harnesses from the liner. You can then set the liner aside.

Note that you can also change the fuel filter without removing the fender well liner. However, removing the liner makes the process easier, especially if you have limited mobility in your arms.

Disconnecting the Water In Fuel (WIF) sensor

Firstly, locate the WIF sensor at the bottom of the fuel filter. You will need to disconnect the WIF connector and let it hang loose. You can do this by hand, or if needed, use a strap wrench or channel locks. Be cautious not to spill any fuel as you remove the filter.

Next, remove the WIF sensor from the bottom of the fuel filter. This can be done with an appropriate wrench, socket, or pliers. Take care not to overtighten the sensor when removing it. Once removed, discard the old O-rings and replace them with new ones provided with the new fuel filter. Lubricate the new O-rings with clean engine oil or 2-stroke oil before installing them.

Now, you can reassemble the WIF sensor onto the new fuel filter. Ensure the sensor connector does not become entangled during this process. Hand-tighten the sensor snugly, again being careful not to overtighten it.

Finally, reconnect the WIF electrical connector. The WIF sensor is now successfully disconnected and replaced, and you can proceed to the next steps of changing the fuel filter.

Unscrewing the old fuel filter

To remove the old fuel filter from your 2006 Duramax, you will first need to disconnect the Water-in-Fuel (WIF) sensor electrical connector. This is located at the bottom of the fuel filter.

Once the WIF sensor connector is disconnected, you can proceed to remove the fuel filter. You may be able to do this with your hands if you are strong enough; otherwise, you can use a strap wrench or channel locks to unscrew the filter. Be careful not to spill any fuel as you remove the filter.

After removing the filter, you will need to drain it and verify that the gasket did not stick to the fuel filter housing flange. You can then remove the WIF sensor assembly from the bottom of the fuel filter using a wrench, socket, or pliers. It is important to be careful when removing this sensor, as over-tightening can cause damage.

Lubricating the new fuel filter's O-rings

• Prepare the O-rings: Before lubricating, it's essential to inspect the O-rings for any damage. The new fuel filter should come with new O-rings. Remove the old O-rings from the Water-in-Fuel Sensor (WIF) and discard them. Ensure that the new O-rings are the correct size and fit snugly on the WIF sensor and the outer edge of the fuel filter.
• Choose a suitable lubricant: There are various options for lubricating the O-rings. Common choices include clean engine oil, diesel fuel, Vaseline, or 2-stroke oil. You can also use products specifically designed for this purpose, such as Translube or Transgel. Avoid using grease, as it may contaminate the fuel system.
• Apply the lubricant: Once you have chosen your lubricant, apply it generously to the O-rings. Coat both the large O-ring on the outer edge of the fuel filter and the small O-ring on the WIF sensor. Ensure that the lubricant is evenly distributed and that the O-rings are well-coated.
• Install the WIF sensor: After lubricating the O-rings, carefully install the WIF sensor onto the new fuel filter. Ensure that the WIF sensor connector does not become entangled during installation. Tighten the WIF sensor snugly by hand; do not overtighten it with tools.
• Install the fuel filter: With the WIF sensor in place, you can now install the new fuel filter. This step can be a bit tricky due to the awkward position. Be patient and carefully thread the fuel filter into place. Again, tighten it snugly by hand; overtightening is not necessary.
• Check for leaks: Once the fuel filter and WIF sensor are installed, start the engine and carefully inspect for any leaks. If you notice any leaks, re-inspect your work and ensure that the O-rings are properly lubricated and seated.

Remember, lubricating the O-rings is crucial to achieving a tight seal and preventing fuel leaks. Take your time and ensure that this step is done correctly before proceeding with the rest of the fuel filter replacement procedure.

Bleeding the fuel system of air

Locate the Fuel Filter Housing: The fuel filter on a Duramax engine is typically located on the passenger side of the engine, underneath the hood near the firewall. The housing will have an integrated fuel plunger or priming pump, which is used to bleed the fuel system.

Disconnect the Water-in-Fuel Sensor: Before removing the fuel filter, locate and disconnect the water-in-fuel sensor electrical connector. This sensor is usually attached to the bottom of the fuel filter. You can use a specialised wrench, socket, or pliers for this step. Remember to be gentle to avoid damaging the sensor.

Remove and Replace the Fuel Filter: Unscrew and remove the old fuel filter, being careful not to spill any fuel. Dispose of the contents properly. Some sources recommend draining the old filter once it's removed. Then, take the new fuel filter and lubricate the O-rings with clean engine oil or 2-stroke oil. Make sure not to overtighten the new filter when installing it.

Open the Bleeder Valve: Locate the bleeder valve or screw, usually towards the driver's side of the fuel priming pump. Loosen the bleeder screw slightly to release air but do not remove it completely. Opening the bleeder valve will help you purge air from the fuel system.

Prime the Fuel Filter: Using the integrated hand pump or priming pump on the fuel filter housing, repeatedly pump diesel fuel into the new filter. Keep pumping until all air escapes and diesel fuel begins to flow out of the bleeder valve or screw. This process may take some time and effort, so be patient.

Close the Bleeder Valve and Reinstall Components: Once diesel fuel starts flowing out of the bleeder valve, immediately tighten and close the valve. Clean up any fuel spills to ensure easy detection of leaks. Reinstall the inner fender and intake tube, or any other components you removed for access.

Start the Engine and Check for Leaks: After reassembling, start the engine and let it idle for a few minutes. Check the fuel filter and bleeder valve for any signs of leaks. If the engine runs rough for an extended period, turn it off, and re-bleed the system at the fuel filter housing.

It is important to note that failing to bleed air from the fuel system before starting the vehicle can place additional strain and excessive wear on the high-pressure injection pump. Therefore, take your time and ensure that all air is purged from the system before starting your Duramax engine.

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