Replacing Fuel Tank Vent Valve: A Step-By-Step Guide

Replacing a fuel tank vent valve is a relatively simple task that can save you a significant amount of money compared to taking your car to a dealership. The fuel tank vent valve is an essential component of your car's fuel system, allowing the tank to breathe and preventing a vacuum from forming, which would cause fuel flow to stop. While the process of replacing the valve can vary depending on your car's make and model, it typically involves removing the fuel tank or accessing the engine bay to reach the valve. Before beginning any work, ensure you have the necessary tools and safety equipment, and refer to your car's repair manual for specific instructions.

Identify the problem

The fuel tank vent valve, also known as the canister purge valve, is an integral part of an evaporative emission control (EVAP) system. It works by trapping fuel vapours in a charcoal canister. The EVAP system will allow the fuel vapours to be released into your vehicle once it starts to run at a regular speed. This happens through the control of the canister purge valve, which regulates the amount of fuel vapour that enters your engine.

The fuel tank vent valve is also known as a solenoid. The most common symptom of a failing fuel tank vent valve is when it gets stuck open or closed.

• Check Engine Light: This is one of the most common symptoms of a bad fuel tank vent valve. The check engine light can indicate that something is wrong with the EVAP vent. If the computer senses an issue with the vent solenoid, it can trigger the check engine light to alert the driver.
• Pressure in the Gas Tank: An issue with the vent solenoid can cause pressure to build up in the fuel tank. If the valve doesn't work correctly, the pressure in the tank might build up and then spill out when the tank is opened, potentially leading to low transmission fluid.
• Failed Emissions Test: If the EVAP vent solenoid breaks, it can prevent the system from working correctly, causing the car to fail the emissions test and potentially affecting its legal status.
• Rough Idling and Difficulty Starting: If the canister purge valve is not working correctly, it can create a vacuum leak that can affect the engine, leading to rough idling and difficulty starting the vehicle.

If you notice any of these symptoms, it is important to have your vehicle inspected by a professional mechanic to diagnose the issue and recommend the necessary repairs.

Purchase a replacement valve

When purchasing a replacement fuel tank vent valve, it is important to get the right part for your vehicle. The make, model and year of your car will determine the type of valve you need.

For example, a BMW Mechanic on JustAnswer.com states that the part number for a fuel tank breather valve for a 2019 Mini Cooper hard top is 113907621174, and this will cost around $100 for an OEM part. They also suggest that the installation cost will depend on the shop's labour rate, but it should not take more than an hour.

You can also find replacement fuel tank vent valves on Amazon.com and CarParts.com. Amazon offers a wide range of options, including:

• Universal vent valves that fit various models, such as the Dorman 911-001, which costs around $19.
• Vent valves for specific car brands, such as Ford, Jeep, Lincoln, and Dodge.
• Vent valves with additional parts, such as a grommet seal, hose barb fitting, or pressure sensor.

CarParts.com also offers a range of fuel tank vent valves for various makes and models, with prices starting at $9.

It is important to note that some valves may be more difficult to find and replace than others. For example, one user on ExpeditionForum.com mentions that their Ford Expedition's fuel tank vent valve is welded to the tank, making it challenging to replace. In such cases, it may be necessary to consider alternative repair methods, such as epoxy or welding.

Remove the old valve

To remove the old valve, first identify its location. In some vehicles, the fuel tank vent valve is located near the canister behind the tank, while in others, it is situated under the intake plenum in the valley between bank 1 and 2 valve covers.

Once you have located the valve, you will need to remove any hoses or clamps attached to it. Cut the clamp with a razor knife or razor blade. If the hose has a quick-connect fitting, press in on both sides of the connector and pull it back. Be careful not to use excessive force, as you do not want to break the nipple.

If the valve is held in place by a bracket, you will need to remove it by wiggling it free. You may need to use a pair of pliers to hold the end of the hose while gently turning the valve back and forth to detach it.

In some cases, you may need to remove additional components to access the valve. For example, you may need to lower the fuel tank, remove the pump assembly, or take out the intake plenum.

Make sure to have a container ready to catch any fuel that may spill during the removal process.

Prepare the new valve

Before you begin the installation of the new valve, ensure that you have all the necessary parts. This includes the new valve itself, a hose clamp, and any other relevant components depending on your vehicle's specific requirements.

For the new valve, you can opt for a universal vent valve, which is a more cost-effective option. Alternatively, you can choose to purchase a vehicle-specific valve from the manufacturer. If you are unsure about which valve to buy, consult a mechanic or a knowledgeable salesperson at an auto parts store.

Once you have the new valve, inspect it to ensure that it is in good condition and free of any defects. Check for any signs of damage or imperfections that may affect its performance.

If your new valve requires assembly, carefully follow the instructions provided by the manufacturer. Make sure all components are securely attached and functioning properly.

Now, refer to the instructions or a repair manual specific to your vehicle's make and model to determine the exact procedure for installing the new valve. The steps may vary depending on the vehicle, so having this information will ensure a more accurate and safe installation.

Before installing the new valve, clean the surrounding area to remove any dirt, grease, or debris. This will help ensure that no contaminants enter the fuel system during the installation process.

When you are ready to install the new valve, follow the instructions carefully, making sure to tighten all connections securely and route any hoses or wires correctly. If your vehicle uses hose clamps, ensure that they are properly positioned and tightened to prevent leaks.

After installing the new valve, it is important to verify that it is functioning correctly. Start the vehicle and check for any signs of leaks or unusual behaviour. If everything appears to be in order, take the vehicle for a test drive to ensure that the valve is working as intended.

Finally, if your vehicle has an on-board diagnostic system, it may be necessary to reset any error codes related to the fuel system or vent valve. This can be done using a diagnostic scanner tool, which will clear any existing codes and allow the system to start fresh with the new valve in place.

Install the new valve

Now that you have removed the old valve, it's time to install the new one.

Firstly, ensure that you have the correct valve for your vehicle. In some cases, you may need to purchase a specific valve from a dealership, while in other cases, you may be able to use a universal valve.

Before installing the new valve, check if it comes with a new seal or grommet. If not, you may need to purchase one separately or reuse the old one if it is still in good condition.

Next, lubricate the new valve and the grommet, if applicable, to make the installation process easier.

Now, carefully insert the new valve into the grommet or rubber mounting hole, ensuring that it is securely in place.

If your valve has any hoses or clamps attached, make sure to secure them properly. You may need to cut and replace some hoses, depending on their condition. Ensure that all connections are tight and secure to prevent leaks.

Finally, refer to the vehicle-specific instructions for any additional steps required to complete the installation of the new valve. This may include reconnecting various components that were removed to access the old valve.

Once the new valve is installed, it is important to test your vehicle to ensure that the issue has been resolved. Take your vehicle for a drive and fill up the fuel tank to check for any leaks or abnormal behaviour.

Frequently asked questions