Fuel Filter Maintenance: Drain Fuel Or Not?

Changing a fuel filter is a messy job, but it's not too complicated. It's important to relieve the pressure in the fuel system before you start, and you'll also need to disconnect the battery and jack up the car if the filter is underneath. You'll also want to place a drain pan or bucket underneath the fuel filter to catch any fuel that spills out. Once you've located the fuel filter, you can remove the clips holding it in place and slide out the fuel lines. Then, simply slide the old filter out of its bracket and replace it with a new one, making sure to point the arrow in the correct direction. Finally, reattach the fuel lines, lower the vehicle, and check for leaks.

Draining the fuel tank

Using a Hose

This is the most common and straightforward method. All you need is a hose and a container to collect the fuel. Insert the hose into the tank and suck on the other end to start the flow of fuel. Then, transfer the fuel to the container. This method doesn't require any specialised equipment, but it carries some risk of inhaling toxic fumes, and fuel can get into your mouth, which is dangerous.

Using a Compressed Air System

Draining a fuel tank with an air compressor is easy, and the process is straightforward. However, you will need tools like an air compressor, a fuel tank adapter, and a fuel line. Connect the fuel line to the tank adapter and the adapter to the air compressor. Once set up, start the compressor, and the resulting pressure will force the fuel out of the tank.

Using a Manual Pump

This method uses a manual pump, a fuel tank adapter, and a fuel line. Connect the fuel line to the tank adapter and the adapter to the manual pump. Place a container nearby to collect the fuel. Start the pump, and the fuel will be forced out of the tank. When you're done, disconnect the fuel line, turn off the pump, and store the tools safely.

This method may not work on all cars. Locate the drain plug on your fuel tank, usually near the bottom. Use a wrench to loosen it, and fuel will start to drain out. Make sure to have a wide-mouthed container, such as a basin, to catch the fuel.

Additional Tips:

• If you have a modern car, refer to your vehicle's service manual to locate the fuel filter. Some fuel filters are located along the fuel line on the bottom of the car, while others are in the engine bay.
• Before starting any work, relieve the pressure in your vehicle's fuel system and disconnect the battery.
• Place a bowl or bucket under the fuel filter to catch any fuel that drips or pours out.
• Wear eye protection and gloves to protect yourself from fuel splatter.
• Be careful not to spill fuel onto the ground.

Relieving fuel pressure

Locate the Fuel Pump Fuse:

First, you need to locate the fuse box that contains the fuel pump fuse. Most vehicles have one fuse box inside the car and another 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, use a pair of needle-nose pliers or plastic tweezers to remove it. 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 the fuel pump functioning, there may still be enough fuel in the lines to start the engine briefly.

Start the Engine:

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

Re-insert the Fuel Pump Fuse:

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

Alternative Methods:

There are alternative methods to relieve fuel pressure, depending on your vehicle's make and model:

• Removing the gas cap: This can help relieve some pressure, but may not be effective for all vehicles.
• Using a Schrader valve: Some vehicles have a Schrader valve on the fuel rail. Drape a rag over the fitting to absorb any spilled fuel, then push down on the valve to release pressure.
• Disconnecting the inertia switch: Unplug the inertia switch, crank the engine, replace the fuel filter, then plug the switch back in.
• Running the engine until it dies: You can remove the fuel pump fuse or relay and start the engine. Let it run until it dies due to lack of fuel.

Remember, relieving fuel pressure is just one step in the process of changing a fuel filter. Always refer to your vehicle's service manual or a trusted mechanic for comprehensive instructions on fuel filter replacement.

Disconnecting the battery

To disconnect the battery, follow these steps:

• Locate the Battery: The battery is usually located in the engine bay, but it can also be found in the trunk or under the hood.
• Identify the Negative Terminal: The negative terminal is typically marked with a "-" symbol or a black cover.
• Loosen the Nut: Use a hand or socket wrench to loosen the nut that holds the cable onto the negative terminal. You don't need to remove the nut completely.
• Disconnect the Cable: Remove the cable from the negative terminal. This will prevent the engine from being started accidentally.
• Secure the Cable: Tuck the negative cable to the side of the battery to ensure it doesn't accidentally come into contact with the terminal.

It is important to note that disconnecting the battery may reset some of your vehicle's settings, such as radio presets or clock settings. You may need to reprogram these settings after reconnecting the battery.

Additionally, always refer to your vehicle's service manual for specific instructions and safety precautions related to battery disconnection and fuel filter replacement.

By following these steps and taking the necessary precautions, you can safely disconnect the battery and proceed with changing the fuel filter.

Locating the fuel filter

The exact location of the fuel filter depends on the vehicle's make and model. For example, 1995-2002 Honda Accord models have the fuel filter near the brake master cylinder on the back of the engine. If you own a 2002 Toyota Corolla, the fuel filter can be found underneath the rear seat cushions. It is inside the fuel tank as part of the fuel pump assembly but is replaceable separately.

There are two common locations fuel filters are mounted in vehicles. 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 should refer to your vehicle's service manual to help you determine which place to look. You may need to access the fuel filter from inside the cabin of some vehicles.

Removing the fuel filter

Removing the Old Fuel Filter

Before you change your fuel filter, you must relieve the pressure in your vehicle's fuel system. You can do this by locating your vehicle's fuse box and removing the fuse for the fuel pump. Once you have removed the fuse, start the engine—the engine should sputter and die.

Now that the engine is off for the remainder of this project, disconnect the negative terminal on the battery. Removing the cable from the negative terminal will prevent the engine from being started while you work. You will need to use a hand or socket wrench to loosen the nut holding the cable onto the negative terminal, but you do not need to remove the nut completely.

Next, locate the fuel filter. There are two common locations fuel filters are mounted in vehicles: along the fuel line on the bottom of the car, just past the fuel pump, or in the engine bay on the line that leads to the fuel rail. Refer to your vehicle's service manual to help you determine the correct location.

If the fuel filter is located on the underside of your vehicle, you will need to jack up the car to access it. Slide the jack under the car at one of its designated jack points, then either pump or twist the handle to raise the vehicle. Once the vehicle is jacked up, place jack stands underneath it before working under the vehicle.

Place a bowl or bucket beneath the fuel filter to catch any fuel that drips or pours out. Then, 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, then use a flat-head screwdriver to pop them out of the holes. These clips may break as you remove them, so purchasing replacement clips along with your fuel filter is advised.

With the clips removed, slide the fuel lines away from the filter and tip them toward the bowl or bucket to catch any spilled gasoline. Make sure to wear eye protection and gloves during this step to protect yourself from fuel splatter.

Finally, 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. The fuel filter will have a slight bell shape, allowing it to slide out in only one direction.

Frequently asked questions