Replacing The L5p Fuel Filter: Step-By-Step Guide

Changing the L5P fuel filter is a relatively straightforward process, but it's important to have the right tools and follow the correct steps for a successful outcome. The L5P fuel filter is typically located in front of the fuel tank, making it more accessible than those found in the engine bay. Before beginning the process, ensure you have the necessary tools, such as a 36mm socket for the filter housing. It is also recommended to refer to a trusted source, such as a YouTube video or a forum, for detailed instructions and visuals to guide you through the process.

Ensure you have the right tools

To ensure you have the right tools to change an L5P fuel filter, you'll need a few specific items.

First, you'll want to make sure you have the correct size socket for the filter housing. In this case, that would be a 36mm socket. It's also a good idea to have a drain plug to let fuel leak out, and some sort of container to catch it in, such as a glass jar. This will allow you to check for water and contaminants in the fuel.

You'll also need a new fuel filter, and it's recommended to get an upgraded filter base kit. This will allow you to change over from the stock cartridge-style filter to a spin-on canister-style filter, which provides increased filter capacity and longer change intervals. The Fleece Performance L5P fuel filter upgrade kit is a popular option, and it includes a filter base with integral mounting, a distribution filter block/filter coupler, quick disconnect fittings, and a 1/8" NPT port for fuel pressure monitoring.

Finally, you'll want to make sure you have the proper tools for the priming procedure, which may vary depending on your specific vehicle.

Drain the fuel

To drain the fuel, you will need to locate the drain plug, which is usually found at the bottom of the fuel filter housing. Place a container under the drain plug to catch the fuel and then remove the plug. Allow the fuel to drain completely before reinstalling the plug.

It is important to note that fuel is highly flammable, so take the necessary precautions when performing this task. Work in a well-ventilated area and avoid any open flames or sparks. Make sure you are wearing the appropriate safety gear, such as gloves and eye protection.

Once the fuel has been drained, inspect it for any signs of water or contaminants. This can be done by draining the fuel into a clear glass jar and allowing it to settle. If there are any water droplets or particles in the fuel, it is an indication that your fuel system may need further attention.

After inspecting the fuel, it is important to clean the drain plug and the surrounding area before reinstalling it. This will help ensure that no dirt or debris enters your fuel system. Use a clean rag to wipe down the plug and the area around it.

Finally, before proceeding with the rest of the fuel filter change, make sure that the drain plug is securely tightened to prevent any leaks.

Remove and clean parts

To remove and clean parts, start by letting a bunch of fuel leak out. Then, remove the gaskets and clean off the parts. Ensure that you don't lose any parts.

The next step is to inspect the diesel fuel system for contamination. Turn the bowl upright and pull the filter down. Check for water and contaminants in the fuel. You can do this by using the drain plug first, preferably into a glass jar.

Finally, wipe out the housing with a clean rag.

Re-install

To reinstall the L5P fuel filter, first, ensure that you have cleaned all the parts and removed the old gaskets. Then, place the new filter into the bowl, ensuring that the filter is facing the correct way. Next, screw the bowl back onto the filter housing, being careful not to over-tighten it, and refer to the torque specs if needed. Once the bowl is secure, reconnect the fuel lines to the bowl, ensuring that they are properly connected. Finally, prime the fuel system by turning the ignition on for fifteen seconds, two times.

Reset oil and fuel filter life

Resetting the oil and fuel filter life on a Duramax L5P engine can be done by following these steps:

• Power up the truck: Turn on the ignition without starting the engine.
• Access the DIC (Driver Information Center): Use the buttons on the steering wheel or the instrument cluster to access the DIC.
• Find the "Fuel Filter Life Remaining" option: Navigate through the DIC menu to find this option.
• Reset the fuel filter life: Press and hold the thumbwheel or the appropriate button for about two seconds when the "Fuel Filter Life Remaining" is displayed. A prompt to reset may appear, which you should confirm.
• Shut down the truck: After resetting, turn off the truck completely.
• Wait and restart: Wait for a couple of minutes, and then restart the truck.
• Check the fuel filter life: After restarting, check the DIC again to see if the fuel filter life has been reset to 100%.

If the fuel filter life still doesn't reset, there could be a warranty issue, and it is recommended to take the truck to the dealership for further assistance.

Frequently asked questions