Replacing A Fuel Level Sensor: A Step-By-Step Guide

Replacing a fuel level sensor can be a tricky task, and it's important to ensure you have the right tools and knowledge before attempting it yourself. A professional mechanic will typically charge around $450 to install a new fuel sensor, but with the right guidance and some careful work, it's possible to do it yourself for under $100. This process will involve disconnecting the battery, removing the fuel tank, and carefully detaching and replacing the fuel level sensor before reassembling the various components. It's important to work in a well-ventilated area and be cautious when handling fuel lines to avoid any leaks or breaks.

Characteristics of replacing a fuel level sensor

Disconnect the negative battery cable

Disconnecting the negative battery cable is an important first step when replacing a fuel level sensor. This is because electricity comes from the positive post, and that's why it can be dangerous to handle. It's also a safety issue—you don't want to touch the wrong battery terminal.

Step 1: Prepare your tools and put on safety gear

Before you begin, make sure you have the right tools and safety gear. You will need a 10-millimetre open-end wrench. It is also important to put on safety glasses and gloves and remove any jewellery.

Step 2: Connect a backup power source

Before disconnecting the battery, you need to connect a backup power source to your car to prevent vital data from being erased from your car's computer system. You can use a memory saver, which can be connected via the cigarette lighter or by clamping onto the battery terminals.

Step 3: Disconnect the negative battery cable

Now you are ready to disconnect the negative battery cable. First, locate the black, negative terminal. It is important to disconnect this one first. Loosen the bolt on the negative clamp using your wrench and lift it away from the battery. Be careful not to let your wrench touch the other terminal.

Step 4: Disconnect the positive battery cable

Next, disconnect the red, positive terminal. Again, loosen the bolt and lift the clamp away from the battery and any metal. Make sure to wrap the positive terminal with a cloth or cover it with a plastic cup to prevent it from touching the battery or any metal accidentally.

By following these steps, you can safely disconnect the negative battery cable, which is an essential first step when replacing a fuel level sensor.

Remove the rear seat bottom cushion

To remove the rear seat bottom cushion, you will need to first remove the rear seat itself. This can be done by folding the seat down, removing the bolts, unclipping the cable, and then sliding the top seat forward and out.

Once the rear seat is removed, the bottom cushion can be taken out. It is held in place by two clips at the front, so grab the front middle of each seat and pull up sharply.

If you are driving a Subaru Impreza, you will also need to go to the trunk and disconnect the battery.

Disconnect the wiring from the pump

Disconnecting the wiring from the fuel pump is a crucial step in performing maintenance on your vehicle's fuel system or replacing the fuel pump itself. Here's a detailed guide on how to safely and effectively complete this task:

Prepare Your Work Area:

Before beginning any work on your vehicle, it's important to ensure your safety and have the necessary tools on hand. Park your vehicle in a well-ventilated area with good lighting. Make sure the engine is cool and the ignition is off to avoid the risk of sparks, which could be dangerous when working with flammable fuel. Wear appropriate safety gear, such as gloves and eye protection, to protect yourself from fuel splashes and any debris.

Locate the Fuel Pump and Wiring:

Refer to your vehicle's owner's manual to identify the location of the fuel pump. It is typically found near the gas tank or in the engine compartment. Once you've located the fuel pump, examine the wiring connected to it. Identify the electrical connector that needs to be disconnected.

Relieve Fuel System Pressure:

This is an important safety precaution to prevent the risk of fuel leaks and explosions. Locate the fuel pump relay or fuse and remove it. Start the engine and let it run until it stalls and shuts off. Then, turn off the ignition and reconnect the fuel pump relay or fuse.

Disconnecting the Wiring:

Now, you can focus on disconnecting the wiring from the fuel pump. Different vehicles may have varying connector styles, but the basic principle remains the same. Look for locking tabs, slides, or clips that secure the connector in place. You may need to press, slide, squeeze, or lift these locking mechanisms to release them. Be gentle yet firm, as some connectors may be seized or corroded due to age and exposure to fumes. If necessary, use a pick or small screwdriver to carefully pry or lift the locking tab.

In some cases, you may need to push in at the bottom of the connector while simultaneously pulling on the outer sleeve to release it. If the connector is resistant, you can try using a flat-head screwdriver to depress the locking tab while you pull on the connector. Always be cautious and patient during this process to avoid damaging the connector or the wiring.

If you encounter significant resistance or if the connector is seized, you may need to apply a penetrant spray, such as WD-40, to help loosen the connection. Allow the penetrant to work for some time before attempting to disconnect again.

Handling Corrosion and Damage:

If you notice corrosion or damage on the connector or wiring, take extra care when attempting to disconnect. Corrosion can fuse the connector and the port together, making it challenging to release. In such cases, gently work on loosening the connection by wiggling or twisting the connector carefully. You may need to use a penetrant spray and allow it to soak for a longer period to help break down the corrosion.

If the connector is extensively damaged or corroded, consider replacing it with a new one. You can transfer the wires from the old connector to the new one using a small pick tool. Alternatively, you can reuse the connector by securing it with a zip tie to hold it in place.

Post-Disconnection Care:

Once you've successfully disconnected the wiring from the fuel pump, it's important to handle the exposed wires with care. Ensure that there are no open flames or sparks nearby, as the fuel system is highly flammable. Store the vehicle in a well-ventilated area, and be cautious when working on any further repairs or maintenance.

Remember to consult your vehicle's manual for specific instructions related to your make and model. Additionally, always prioritize your safety and the safety of those around you when working on any vehicle maintenance or repair tasks.

Disconnect the fuel lines

Disconnecting the fuel lines is a crucial step in replacing a fuel level sensor. Here is a detailed guide on how to safely and effectively complete this task:

Before beginning, ensure you have the necessary tools and safety equipment. Safety glasses and gloves are recommended to protect yourself from any fuel spills or splashes. It is also important to work in a well-ventilated area to avoid inhaling fumes.

Locate the fuel lines: The fuel lines are usually found near the fuel tank or engine bay. Identify the specific lines that need to be disconnected, as there may be multiple lines present.

Relieve fuel system pressure: Before disconnecting any fuel lines, it is crucial to relieve the pressure in the fuel system. This can be done by following the instructions in your vehicle's service manual. This step is important to prevent fuel spray or leakage when disconnecting the lines.

Prepare the work area: Clean the area around the fuel lines and plug to ensure it is free of contaminants. Any debris or dirt falling into the fuel tank can cause issues later on.

Be gentle and careful during this step to avoid damaging the fuel lines. If the lines are made of plastic, be extra cautious as they can be more prone to breakage. If you are disconnecting metal fuel lines, a tool such as a screwdriver may be needed to carefully pry or loosen the connection.

Once the fuel lines are disconnected, set them aside safely. Ensure that the disconnected lines are secured or capped to prevent any fuel leakage or spillage.

It is important to note that working with fuel lines can be dangerous, and if you are uncomfortable or unsure at any point, it is best to consult a professional mechanic.

Remove the pump assembly

Before removing the pump assembly, ensure that you have the necessary tools and safety equipment. Wear safety glasses and gloves, and keep a fire extinguisher nearby. It is also important to work in a well-ventilated area.

Now, to remove the pump assembly, you will need to:

• Disconnect the negative battery cable.
• Remove the rear hatch or open the trunk and take out the spare tire.
• Detach the gas and electric power cables connected to the fuel tank.
• Unclip the electrical cables using a pair of small screwdrivers and remove the tank holders.
• Take out the bolts on the bearers that support the tank under the vehicle. You may need a friend to help you hold the tank as you do this.
• Locate the pump assembly, which is connected to the fuel level sensor. The sensor is often situated at the bottom of the transmitting device.
• Disconnect the wiring from the pump assembly. Be very careful not to break the fuel lines.
• Remove the nuts or screws holding the pump assembly to the tank.
• Lift out the pump assembly. This may require some twisting and turning to get it out.

Once the pump assembly is removed, you can separate the level sender or sensor by disconnecting the connector and clipping the assembly apart.

Frequently asked questions