Replacing Fuel Neck Assembly: Step-By-Step Guide For Beginners

Replacing a fuel neck assembly is a complex process that requires a good amount of patience, especially if there's rust. The fuel filler neck is the long tubular part that connects a vehicle's diesel fuel or gas tank to the fuel cap. It is usually attached to a tube or tubes connected to the gas tank. To replace the fuel filler neck, you will need to remove the bolts from the tip of the neck and possibly the neck itself, before loosening the bracket holding the tube to the neck and pulling the neck down and out.

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Locate the fuel filler neck and check for damage

To locate the fuel filler neck, open the fuel filler door and look for the fuel filler inlet. The fuel filler neck is a solid piece of formed tubular steel that joins the fuel filler inlet and the rubber fuel fill hose on the gas tank. It is connected to the body inlet cutaway with steel screws and is fitted inside a rubber hose attached to the vehicle's fuel tank.

Once you have located the fuel filler neck, check for any exterior damage. Look to see if all the mounting screws are inside the fuel door area and verify that the rubber hose and clamp are visible and undamaged. If you cannot check the rubber hose and clamp under the vehicle, you may need to remove a cover that protects the fuel hose from debris.

Common signs of a bad or failing fuel filler neck include a lingering fuel smell, the Check Engine Light coming on, and fuel leaks. If you notice any of these issues, it is important to have the vehicle inspected by a professional technician to determine if the neck needs to be replaced.

Check for fuel vapour leaks

Once you have replaced the fuel filler neck, you will need to check for fuel vapour leaks. Fuel leakage in a vehicle can be very dangerous. While liquid fuel does not burn, the vapours are highly flammable. If there is a leak at the fuel filler neck, there is a risk of the fuel vapours igniting when rocks are thrown up into the wheel well or under the vehicle, causing a spark.

Step 1: Get a Transfer Tank or Portable Fuel Can

Remove the fuel filler cap and empty the fuel into the fuel filler neck, fuelling up the tank. Try not to drain any fuel on the ground or neck area.

Step 2: Check for Leaks

Wait 15 minutes away from the vehicle, then return and check for leaks. Look under the vehicle for any fuel drops and sniff around to see if you smell any vapours. You can also use a combustible gas detector to check for any vapour leaks that you cannot smell.

If there are no leaks, you can continue. However, if you find a leak, check the connections to see if they are tight. If you had to make adjustments, make sure to check for leaks again before continuing.

Note: If there are any vapour leaks, when driving the vehicle, the vapour sensor will pick up the leak and display the engine light.

Prepare your vehicle for the replacement

To prepare your vehicle for the replacement of the fuel neck assembly, you will need to gather the necessary tools and materials, including a new fuel filler neck, a floor jack, jack stands, wheel chocks, a nine-volt battery saver, a flathead screwdriver, fuel-resistant gloves, and a combustible gas detector. Here is a step-by-step guide to prepare your vehicle for the replacement:

• Park your vehicle on a flat, hard surface and ensure that the transmission is in park for automatics or in first gear for manuals. This will create a stable and secure base for the replacement process.
• Place wheel chocks around the front tires, as the rear of the vehicle will be lifted. Engage the parking brake to lock the rear tires from moving, ensuring the vehicle remains stationary during the process.
• Install a nine-volt battery saver into the cigarette lighter to maintain the vehicle's electrical settings. This step is optional, but it helps preserve your current vehicle settings.
• Disconnect the battery by opening the vehicle's hood and removing the ground cable from the battery's negative post. This step is crucial for safety, as it disables the power to the fuel pump or sending unit.
• Using a floor jack, carefully lift the vehicle from underneath, following the manufacturer's specified jacking points. Ensure that the vehicle is lifted high enough for the wheels to be completely off the ground.
• Place jack stands under the jacking point locations and lower the vehicle onto them. Refer to the vehicle's owner's manual for the exact jacking points, as they may vary depending on the car model.
• Open the fuel door to access the fuel filler neck. If your vehicle has a cover protecting the fuel hose from debris, remove it to inspect the hose and clamp for any signs of damage.
• Remove the mounting screws or bolts attached to the cutaway, securing the fuel filler neck in place. This step will allow you to detach the fuel filler neck from the vehicle's body.
• Detach the fuel filler cap cable from the fuel neck and set it aside. This step ensures that the cable does not interfere with the replacement process.
• Locate the fuel tank by going under the vehicle. If your vehicle has a spare tire, you may need to remove it to gain better access to the fuel tank and the surrounding components.
• Prepare the necessary tools and the new fuel filler neck assembly close at hand. Ensure you have a suitable replacement part that matches your vehicle's make and model.

By following these steps, you will have your vehicle ready for the fuel neck assembly replacement. Remember to work in a well-ventilated area and take the necessary safety precautions when working with automotive fuel systems.

Remove the fuel filler neck

To remove the fuel filler neck, you will need to first locate the fuel filler neck and inspect it for any exterior damage. Check the mounting screws, rubber hose, and clamp for any signs of damage or wear. If your vehicle has a cover protecting the fuel hose from debris, you will need to remove it to access the fuel filler neck.

Once you have located the fuel filler neck and inspected it for damage, you can begin the removal process. Park your vehicle on a flat, hard surface and engage the parking brake. You may also need to disconnect the battery and ground cable to disable the power to the fuel pump or sending unit.

The next step is to raise the vehicle using a floor jack and place jack stands under the jacking points. For most modern cars, the jacking points are located on the pinch weld just under the doors along the bottom of the car. Be sure to follow the vehicle owner's manual for the proper jacking locations.

Now you can open the fuel door and remove the mounting screws or bolts attached to the cutaway. Disconnect the fuel filler cap cable from the fuel neck and set it aside.

At this point, you will need to locate and access the fuel tank. Depending on the make and model of your vehicle, you may need to lower the fuel tank to gain access to the fuel filler neck. Loosen and remove the straps to the fuel tank and lower it enough to reach the vent hose attached to the top of the tank. Remove the clamp and vent hose to create more clearance.

Finally, you can remove the fuel filler neck by detaching the clamp on the rubber hose and twisting the fuel filler neck to pull it out of the rubber hose. Guide the fuel filler neck out of the area and remove it from the vehicle. Be careful not to spill any fuel during this process.

Note: It is recommended to have the vehicle's fuel tank at a quarter tank or less when removing the fuel filler neck.

Install the new fuel filler neck

To install the new fuel filler neck, you will need to follow these steps:

Firstly, you will need to manoeuvre the new fuel filler neck into place, attaching the tube and bracket to the neck component. Ensure that the filler neck is correctly aligned with the cutaway and that the mounting holes are lined up. You can then tighten the bolts that secure the neck to the vehicle.

Next, you will need to attach the fuel tank straps and tighten them until they stop. Torque the mounting nuts to the fuel tank specifications. If you are unsure of the torque value, you can tighten the nuts by a further 1/8 turn using blue locktite.

Now, you will need to align the fuel filler neck with the cutaway in the fuel door area. Install the mounting screws or bolts into the neck and secure them tightly. Attach the cable of the fuel filler cap to the neck and screw on the fuel filler cap until it locks into place.

Finally, you can reconnect the ground cable to the battery's negative post. Ensure that the connection is good and that the battery clamp is tightened.

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