Changing Fuel Filters: Easy Diy Or Mechanic Job?

Changing a fuel filter is a simple and effective way to keep your engine running smoothly. It is an important part of regular car maintenance, as it helps to prevent contaminants from entering the engine and fuel injectors, which can cause damage. While the process of changing a fuel filter is not particularly difficult, it does require some basic knowledge of car mechanics and safety precautions. It is also important to note that fuel filters are typically located in different places depending on the make and model of the vehicle, so it is crucial to refer to the owner's manual or a trusted mechanic for specific instructions.

Depends on your vehicle

The ease of changing a fuel filter depends on your vehicle. Many late-model vehicles no longer have accessible fuel filters, and some are integrated into the fuel pump assembly, which is often inside the fuel tank. In these cases, you will need to hire a trained technician to replace the filter.

However, if your vehicle has an externally serviceable fuel filter, you may be able to change it yourself. The basic procedure is the same for all vehicles, although the details vary. The first step is to relieve the pressure in the fuel system. Then, locate and remove the old fuel filter, taking care to note its orientation, as the fuel flows in a particular direction. Next, install the new fuel filter, ensuring it is facing the correct way. Finally, check for leaks and start the engine.

The cost of parts for a fuel filter replacement ranges from $15 to $125, while professional labour costs between $30 and $100. The time required for a DIY replacement is typically 15 to 60 minutes.

Fuel filters are critical

Fuel filters are also critical because they are relatively simple and inexpensive to replace—yet failure to change them can lead to a breakdown as insufficient fuel gets to the engine. Replacing your fuel filter on schedule is a simple and effective way to keep your engine running healthily.

Most vehicles have two fuel filters. There's one in the fuel tank, often called a strainer, and there's one in the main fuel line. The filter material is made from plastic or specially coated pleated paper.

Gasoline fuel filters are rated in microns. Most modern vehicles with fuel-injection systems use filters rated between 10 and 30 microns. This is because the injectors have very tiny openings to allow fuel to pass through under high pressure into the engine, so they must remain free of debris.

A restricted fuel filter may cause your fuel pump to become noisy, damaged or fail completely. Contaminants that get past a dirty fuel filter can damage, clog or cause a fuel injector to leak, leading to all types of engine problems.

Relieving the pressure

Locate the fuse box:

Find the fuse box that contains the fuel pump fuse. Most vehicles have a fuse box in the interior and under the hood. Refer to your vehicle's owner's manual or the auto maker's website to identify the correct fuse box and fuse.

Remove the fuel pump fuse:

Once you've located the correct fuse box, use the diagram provided on the fuse box cover or in the owner's manual to identify the fuse for the fuel pump. Use a pair of needle-nose pliers or plastic tweezers to remove the fuse. With the fuse removed, the fuel pump will not function when you start the engine.

Ensure the vehicle is not in gear:

Make sure automatic vehicles are in park and vehicles with a standard transmission are in neutral with the parking brake engaged. This is important because, even without a fresh fuel supply from the tank, there will be enough fuel in the lines to start the engine and allow it to run briefly.

Start the engine:

Insert the key into the ignition and turn it to start the engine. The engine should start easily as it expends the remaining fuel in the system. Allow the engine to run for a minute or two before shutting it off. This will help relieve the pressure in the fuel lines.

Re-insert the fuel pump fuse:

With the pressure relieved and the engine off, you can re-insert the fuse for the fuel pump and place the cover back on the fuse box. Make sure the vehicle is off before replacing the fuse. Do not start the engine again after inserting the fuse.

Disconnect the battery:

Now that you're done starting the engine, disconnect the negative terminal on the battery to prevent any accidental startups while you work on replacing the fuel filter. Use a hand or socket wrench to loosen the nut holding the cable onto the negative terminal, but you don't need to remove it completely. Tuck the negative cable to the side to ensure it doesn't come into contact with the terminal.

By following these steps, you can safely relieve the pressure in your vehicle's fuel system before replacing the fuel filter. Remember to refer to your vehicle's owner's manual or a trusted mechanic for specific instructions for your car model.

Removing the old filter

Before you start, make sure your vehicle is safely parked in an area with ample working space.

Depressurise the fuel system

This is an optional step but it will help to minimise any spills when you remove the old fuel filter. If your vehicle has an easily accessible fuel relay or fuse, remove it, then start the engine. As the fuel pump will not be operating, the engine will eventually stall. Once the engine stalls, shut off the ignition and replace the fuse or relay.

Locate the fuel filter

Check your vehicle's service manual to find the fuel filter. The most common location for modern vehicles is along the fuel line on the bottom of the car, just past the fuel pump. In some vehicles, the fuel filter is located in the engine bay on the line that leads to the fuel rail. You may need to jack up your car to access the fuel filter.

Place a bowl or bucket beneath the fuel filter

Although you've relieved the pressure in the fuel line, there may still be fuel left in the line that could spill out when disconnected from the fuel filter.

Remove the clips holding the fuel filter in place

Most fuel filters are held in place by two plastic clips. Locate the clips on either side of the cylindrical fuel filter and use a flat-head screwdriver to pop them out. These clips may break as you remove them, so it's advised to purchase replacement clips along with your new fuel filter.

Remove the fuel lines from the filter

With the clips removed, slide the fuel lines away from the filter and towards the bowl or bucket to catch any spilled gasoline. Wear eye protection and gloves to protect yourself from fuel splatter.

Slide the fuel filter out of its bracket

The fuel filter is likely held in place by a metal bracket that wraps around its outer housing. With the fuel lines disconnected, you can slide the fuel filter out of the bracket by pushing it towards the front of the car. The fuel filter will have a slight bell shape, allowing it to slide out in only one direction.

Installing a new filter

Before installing a new fuel filter, compare its specifications with the old one. Check that the new filter has the same outside diameter, nozzle size, and bracket fit as the old one. If the new filter doesn't match the old one, you will need to return it and purchase the correct replacement. Do not try to force an incompatible filter into place, as this may damage the housing and cause a leak.

Once you have the correct replacement filter, slide it into its bracket. The filter should slide in easily and stop when it is seated properly. If you find yourself pushing hard on the filter, it is likely not the right one.

Next, fasten the fuel filter to the fuel line. Slide the fuel lines onto the front and back of the filter, ensuring they are snug on the nozzles. Then, secure the lines in place with the plastic clips. If a clip breaks, do not drive the vehicle until you replace it.

Finally, lower the vehicle off the jack stands. Jack up the car to relieve the weight on the stands, then slide them out. Once the vehicle is safely on the ground, reconnect the battery.

Now that you've installed a new fuel filter, it's time to start the vehicle and check your work. Don't be alarmed if the engine takes longer than usual to start. Once it starts, check for any fuel leaks. If you notice a leak, shut off the engine, retighten the fuel line connections, and restart the engine.

Frequently asked questions