Replacing Your Motorhome Fuel Pump: A Step-By-Step Guide

Changing the fuel pump in a motorhome is a complex task that requires careful planning and patience. The process typically involves dropping the fuel tank, which is best done when empty, although pump failure often occurs when the tank is full. One way to avoid dropping the tank is to cut a hole in the floor to access the pump, but this is not recommended as it can cause water intrusion and damage the subfloor. When replacing the fuel pump, it is also a good opportunity to inspect the tank interior and replace fuel lines and filters. The cost of replacing a fuel pump can vary depending on location, ranging from $600 to $1000 or more.

Cutting a hatch in the floor

If you decide to go ahead with cutting a hatch, the first step is to identify the exact location of the fuel pump. You will need to cut the hatch in the right place to be able to access and remove the pump. Make sure you also locate the fuel lines and wiring harnesses connected to the pump.

Once you have determined the location, you can start cutting the hatch. Use the appropriate tools to cut through the floor and create an opening that is large enough to access and remove the fuel pump. Be very careful not to damage any surrounding components or structures.

After cutting the hatch, you will need to seal the edges of the cutout to prevent water intrusion, which can cause damage to your subfloor. Use a suitable sealant or caulk to create a watertight seal around the edges of the hatch.

With the hatch in place, you can now access the fuel pump for inspection, repair, or replacement. Remember to have a spare pump ready if you are replacing the old one. Keep in mind that fuel pump seals can dry out, crack, and break apart, so it is important to store your spare pump in a suitable container to maintain its condition.

Finally, always exercise caution when working with fuel systems and follow safety guidelines to prevent accidents or injuries.

Draining and dropping the tank

Firstly, it is important to run the tank as empty as possible. This step is crucial as it makes the tank much lighter and easier to handle. If you have a rubber fuel line for the generator, ensure you disconnect it. It is easier to replace it when the tank is down.

Next, you will need to disconnect the fuel lines and the wiring harness for the pump. You may also need to remove the fuel neck. Once everything is disconnected, carefully lower the tank. You can use a floor jack or a hydraulic table to support and lower the tank. If your tank is only accessible by dropping it, ensure you have a good support system in place to avoid any injuries or damage to the tank.

When lowering the tank, be cautious if it contains fuel. Tipping the tank may cause the fuel to slosh out, creating a hazardous situation. To avoid this, ensure the tank is well-supported and slowly lower it, being mindful of the fuel level inside.

Once the tank is lowered, you can proceed to clean the top and inspect the interior. This is also a good opportunity to replace any fuel lines that are easily accessible. Remember to take your time and work in a safe and controlled manner.

Finally, with the tank drained and dropped, you now have access to the fuel pump for replacement. Follow the manufacturer's instructions or seek professional guidance if you are unsure about the specific steps for your motorhome model.

Using an external fuel pump

Firstly, it can save you a lot of time and money. Replacing the in-tank fuel pump typically requires dropping the fuel tank, which is a labour-intensive process. By using an external fuel pump, you can avoid this cumbersome task.

Secondly, an external fuel pump can be more accessible for future maintenance or repairs. You can mount the external pump in a convenient location, making it easier to inspect, replace, or service the pump if needed.

To install an external fuel pump, follow these steps:

• Identify the location for the external fuel pump. It should be mounted securely, preferably on the inner frame rail of the chassis, to protect it from road debris.
• Drain the fuel from your tank as much as possible. Even if your tank is not full, it will still be heavy, so take the necessary precautions to support it safely during the process.
• Disconnect the fuel lines and electrical connectors from the old pump. Be prepared to catch any leaking fuel with a bowl or basin.
• Remove the old pump. This may involve lowering the tank slightly or accessing it through an existing opening. Ensure you have the necessary tools, such as a floor jack, ratchet straps, or a hydraulic table.
• Install the new external fuel pump. Ensure that the ignition wire is properly connected. You may need to refer to specific instructions for the pump you are installing.
• Test the new pump to ensure it is functioning correctly.

It is important to note that using an external fuel pump may not be suitable for all motorhomes, especially those with in-tank fuel pumps. Consult a certified technician or mechanic to ensure that this modification is safe and feasible for your specific vehicle. Additionally, always take the necessary safety precautions when working with fuel and electrical systems.

Replacing fuel lines

Replacing the fuel lines in your motorhome is a crucial part of maintaining your vehicle's performance and safety. Here's a step-by-step guide to help you through the process:

Step 1: Prepare Your Motorhome

Before you begin, park your motorhome on a level surface and engage the parking brake. Ensure you have all the necessary tools and safety equipment, including gloves and eye protection. Place a suitable container underneath the fuel lines to catch any spilled fuel.

Step 2: Drain the Fuel Tank

Completely drain the fuel from the tank to reduce the risk of spillage and minimize the weight of the tank. This step is crucial for your safety and will make the subsequent steps easier.

Step 3: Disconnect the Old Fuel Lines

Locate the fuel lines and carefully disconnect them from the tank, engine, and any other components they are attached to. Be sure to label or mark each line to ensure proper reconnection during the installation of the new fuel lines.

Step 4: Remove the Old Fuel Lines

Using the appropriate tools, carefully remove the old fuel lines from the motorhome. Take note of the routing and any clips or fasteners used to secure the lines in place, as you will need to replicate this during the installation of the new fuel lines.

Step 5: Inspect and Clean the Area

Before installing the new fuel lines, thoroughly inspect the area for any signs of damage, corrosion, or leaks. Clean the area to ensure that no dirt or debris can enter the fuel system during the installation process.

Step 6: Install the New Fuel Lines

Obtain high-quality fuel lines that are compatible with your motorhome's fuel system. Carefully route the new fuel lines along the same path as the old lines, using the clips and fasteners to secure them in place. Ensure that all connections are tight and secure.

Step 7: Refill the Fuel Tank

Once you have confirmed that the new fuel lines are properly installed, you can refill the fuel tank. Be sure to check for any signs of leaks during and after this process.

Step 8: Test and Inspect

Start the engine and check for any leaks or unusual noises. Inspect the new fuel lines and all connections to ensure that everything is secure and functioning properly.

Remember to dispose of the old fuel lines and any spilled fuel properly, following local regulations and safety guidelines. Always prioritize your safety and the safety of those around you when working on your motorhome's fuel system.

Removing fuel neck

To remove the fuel neck, you will need to first loosen the wiring, connectors, and tank straps. You may also need to remove the rear tires for better access. Once the tank straps are loose, carefully lower the tank onto a floor jack. It is important to ensure the tank is secure on the jack and will not slip or tip over.

Next, you will need to disconnect the fuel lines and wiring harness for the pump. Be sure to tag or mark the wiring harness connections so you can easily reconnect them later. With the fuel lines and wiring disconnected, you can now remove the fuel neck from the tank. Take care not to damage the tank or any surrounding components during this process. Place the fuel neck aside in a safe location, as you will need to reinstall it later.

Before proceeding with any further repairs or maintenance, be sure to clean the top of the tank and inspect it for any signs of damage or wear. It is also recommended to replace the fuel filter and any accessible rubber parts while the tank is down. This will help ensure reliable performance and reduce the risk of future issues.

Reinstalling the fuel neck and tank will involve reversing the removal process. Ensure all connections are secure and properly tightened before refilling the tank and starting the engine.

Frequently asked questions