Draining Air After Fuel Filter Change: Step-By-Step Guide

Changing a fuel filter is a messy job, and it's important to be cautious of flammable liquids and combustible fumes. Before starting, it's a good idea to relieve fuel pressure by letting the car sit overnight, removing the gas cap, or removing the fuel pump fuse or relay. When changing the filter, be prepared for some gasoline spillage and have a drain pan ready to catch it. To avoid air entering the system, it's best to perform this task when the gas tank is less than a quarter full.

Remove fuel pump relay

To remove the fuel pump relay, follow these steps:

Firstly, turn on the ignition key and listen for the fuel pump to actuate. You should also listen for any buzzing or clicking noise coming from the fuel pump relay. This will indicate that the relay is functioning as it should.

Next, start the engine and check that there is oil pressure. Look for an oil light indicator on your vehicle, which will go out when there is oil pressure.

Now, park your vehicle on a flat, hard surface, with the transmission in park for automatics or in first gear for manuals. Place wheel chocks around the front tires and engage the parking brake to prevent the vehicle from moving.

Open the hood and locate the fuse box in the engine compartment. The fuel pump relay is usually found inside the fuse box, which is often a long black box with other relays and fuses. However, the location can vary depending on the vehicle, so check your owner's manual if needed.

Remove the cover from the fuse box. Using the diagram on the fuse box cover or in your owner's manual, locate the fuel pump relay. Pay attention to how the relay is positioned, as the new one will need to be installed in the same way.

Use a flathead screwdriver to carefully pry out the fuel pump relay, which is a cube-shaped object with prongs that connect like an electrical plug. Disconnect the plug and any fuse connected to the relay to fully remove it.

With these steps, you can successfully remove the fuel pump relay, which is an important part of the process when learning how to drain the air after a fuel filter change.

Start engine and let it idle until it stalls

After changing the fuel filter, you will need to prime the fuel filter to ensure fuel is circulating in your fuel system. To do this, start your engine and let it idle until it stalls. This will trigger your Check Engine Light. Once the engine stalls, crank it again for about five seconds to release fuel pressure.

This process should relieve most of the pressure, but there could still be some residual fuel that leaks or squirts out when you detach the filter. At this point, turn the ignition back to the OFF position.

If you have a diesel engine, you may need to repeat the process of turning the ignition key to "run" for several seconds, turning it off, and then repeating up to four times. On the fourth or fifth turn, crank the engine, which should start. Make sure to let the engine run for 30 seconds before turning it off and inspecting the fuel filter for any leaks.

If you have a manual primer pump, you can also try pumping the primer handle (this can take anywhere from 50 to 500 pumps) while turning the air-bleed screw until the hissing noise of escaping air stops. Once the noise dissipates, tighten the screw and try to turn the engine.

Disconnect the battery cable

Disconnecting the battery cable is an important safety step when changing your fuel filter. It is marked with a minus sign and is known as the battery ground cable. Disconnecting it will ensure that there is no electrical power near the fuel pump, minimising the risk of sparks. This is crucial as sparks and gasoline fumes are a dangerous combination that could lead to an accident.

To disconnect the battery cable, locate the cable with the minus sign. Set it aside, ensuring that it does not touch any metal surfaces. This will prevent the risk of sparks and electrical issues during the fuel filter change process.

It is worth noting that some people consider disconnecting the battery cable to be unnecessary, especially if the key is not in the ignition. However, it is generally recommended to take this precaution to ensure safety when working with the fuel system.

Once you have finished changing the fuel filter, remember to reconnect the negative battery cable before turning the ignition back on.

Place a drain pan under the fuel filter

To drain the air after a fuel filter change, you must first relieve the fuel pressure. This can be done by removing the fuel pump fuse or relay and allowing the car to idle until it stalls. Once the engine has stalled, crank it for a few more seconds to release any remaining fuel pressure.

Now, it's time to place a drain pan under the fuel filter. This is a crucial step to catch any fuel that may leak from the lines or the filter itself during the detachment process. Some vehicles will continue to leak fuel until everything is reconnected, so it is essential to have the drain pan in place before proceeding.

• Identify the location of the fuel filter by referring to your car's repair manual. This will help you determine the exact placement of the drain pan.
• Select an appropriate drain pan that can catch any fuel spillage. Make sure the drain pan is large enough to cover the entire work area and is made of a material that can safely contain flammable liquids.
• Place the drain pan directly under the fuel filter. Ensure that it is securely positioned and will not move or tip over during the filter change process.
• If your car is raised on a jack, adjust the position of the drain pan accordingly. Make sure the pan is stable and will not obstruct your access to the fuel filter or other components.
• Keep a few rags or towels nearby. In addition to the drain pan, having absorbent materials on hand will help you manage any unexpected spills or leaks effectively.
• If possible, work in a well-ventilated area to prevent combustible fumes from accumulating. This will also reduce the risk of igniting fuel vapors.

By following these steps, you will effectively prepare for any fuel leakage during the fuel filter change process, ensuring a safer and more controlled work environment.

Loosen the fuel filter clamp

To loosen the fuel filter clamp, you will need to locate the fuel filter. This is generally found under the vehicle on the frame rail or in the engine compartment near the firewall. Once you have located the filter, you can begin to loosen the clamp.

The type of clamp you have will determine how you loosen it. Some fuel filters have a quick-release button on either side that you can push to release the filter. Others have hose clamps that can be removed with pliers or a screwdriver. If your vehicle has a screw-type clamp, you will need to locate the screw, which may be behind the filter, and use a screwdriver to loosen it. Be careful not to overtighten hose clamps, as this can damage them.

If your vehicle has a different type of clamp, such as a quick-connect fitting or a banjo fitting, you will need to use the appropriate tool to disconnect the fuel lines from the filter before you can loosen the clamp. Quick-connect fittings require a special disconnect tool, while banjo fittings can be removed with a ratchet or wrench.

It is important to work in a well-ventilated area when performing this task, as combustible fumes can accumulate. Always refer to your vehicle's service manual for specific instructions and take appropriate safety precautions.

Frequently asked questions