How to Change a Diesel Fuel Filter

What You'll Need
New filter with 2 o-rings
Wrench or screwdriver
Rag or container to catch leaking fuel
A small amount of strong tape

A diesel fuel filter is a filter in the fuel line of your vehicle that filters contaminants out of the fuel. These contaminants can include dirt, rust, paint chips, and other material that can cause rapid wear and failure of the fuel pump and injectors. Diesel fuel in particular has less debris removed, so it is important to replace the filter whenever it becomes thick with contamination in order to maximize filtration and get the best use out of the fuel you are burning.

When replacing your filter, make sure that you are in a well-ventilated area away from heat and flame, as the fume buildup could cause fire or explosion.

Step 1 – Locate the Filter

Make sure that your engine is not running. Open the engine bay. The fuel filter is a cylindrical shape with hosing attached at both ends. It will be hooked up somewhere along the fuel line, but the exact location depends on the model of your vehicle. If you have trouble locating it, check your owner’s manual for a diagram.

Step 2 – Detach the Old Filter

There will be several hoses connected to the filter including a water sensor and water-drain plug. Have a rag or container ready to catch leaking fuel when you remove the hoses. Use a wrench or screwdriver to loosen the fittings and pull off the hoses, freeing the filter from the fuel line. Use tape to close the ends of the fuel line to prevent spilt fuel during the exchange.

Step 3 – Install the New Filter

If the old filter was secured with mounting brackets or retaining straps, attach the brackets or straps to the new filter before installing it into the fuel system. The o-rings are rubber washers that go on the bolt that holds the filter in place. Replace the old o-rings with new ones, lubricated with fresh oil. Place the new filter in the empty canister in the fuel line where you have removed the old filter. Turn the filter clockwise. Tighten the bolt to keep it in place, but not too tight or you will get leaks. Attach the hoses, using your wrench or screwdriver to tighten the fittings.

Step 4 – Clean Up

Wipe down the area of the engine to collect old or new oil that may have spilled or collected over time. Close engine bay.

Step 5 – Refill Fuel Lines with Fuel

If you do not refill the fuel lines with fuel before starting your engine, you could seriously damage the internal parts. Inside the car, hold down the accelerator pedal before turning on the engine. This should move fuel into the fuel lines.

Step 6 – Dispose of Old Filter

Do not discard the old filter in the trash, for it contains hazardous material that can hurt the environment. Instead, recycle it at an auto parts store.