Replacing Fuel Pump Motors: A Step-By-Step Guide For Beginners

Replacing a fuel pump motor can be a challenging task, but with careful preparation and the right tools, it can be done safely and effectively. A fuel pump is a small electric motor that transfers fuel from the fuel tank to the engine, and while durable, they sometimes need to be replaced due to wear and tear, contamination, or electrical faults. Before starting, it's important to gather the necessary tools and equipment, including a new fuel pump, and to consult vehicle-specific instructions. The process typically involves relieving the fuel system pressure, locating and removing the old fuel pump, and installing the new one, taking care to avoid any spillage or mess.

How to Replace Fuel Pump Motor

Find the fuel pump

To find the fuel pump, you'll need to locate the fuel tank. The fuel pump is usually found inside the fuel tank of most vehicles with fuel injection. However, modern vehicles with gasoline direct injection (GDI) have a second, high-pressure pump located near the fuel rail in the engine compartment.

In some vehicles, you can access the fuel pump through a fuel pump access door underneath the rear seat. If your vehicle doesn't have this access door, you'll need to drop the fuel tank to reach the pump.

It's important to note that the process of accessing the fuel pump can vary greatly depending on the vehicle's model. You may need to refer to your vehicle's service manual or online resources for specific instructions on locating and accessing the fuel pump in your car.

Additionally, if you're working with the fuel system, it's crucial to take proper safety precautions. Work in a well-ventilated area, preferably outdoors, to minimise the risk of fire or inhaling toxic fumes. Always wear safety gear, such as gloves and protective eyewear, to shield yourself from fuel spills and splashes.

Before attempting any repairs or replacements, ensure you have the necessary tools and equipment, including a new fuel pump and any other specific components for your vehicle. It's also recommended to reduce the amount of fuel in the tank to prevent spillage and make the tank lighter and easier to handle.

Relieve the fuel system pressure

To relieve the fuel system pressure, you can try the following methods:

Method 1:

• Start by running the engine.
• While the engine is on, pull the fuel pump relay, which will cause the engine to stall.
• This method may not be suitable if you have a clogged filter, as there might still be pressure in the lines between the pump and filter.

Method 2:

• With the engine turned off, locate the Schrader valve on the pressure line.
• Press the Schrader valve momentarily, being careful to catch the small amount of fuel spray that will be released.
• This method is suitable if your car cannot start.

Method 3:

• Turn the key in the ignition to the 'Run' position, but do not start the car.
• Listen for the fuel pump, which should be audible for about 3 seconds.
• This quick test will tell you if the fuel pump is functioning and getting power.
• This method will not provide a comprehensive diagnosis of the entire fuel line.

Method 4:

• Disconnect the fuel rail.
• Pull the fuse for the fuel pump.
• Crank the car for a few seconds to relieve the pressure.

Remove the fuel tank

Removing the Fuel Tank

Before removing the fuel tank, ensure that your vehicle is lifted and supported by a jack. It is important to work in a well-ventilated area to minimise the risk of fire and inhaling harmful fumes. Wear safety gear, such as safety glasses and gloves, to protect yourself from fuel spills and splashes.

If your fuel tank is more than half full, drain it into an approved container. This will make the tank lighter and easier to handle, reducing the risk of spills.

Now, locate the rear strap of the tank. Undo the strap by unscrewing the 2 or 3 13mm bolts holding it up. Then, unbolt the middle strap and let the tank hang. Next, unbolt the two bolts on the front of the tank attached to the frame bracket. Slide the tank back to clear the front bracket. Lower the rear of the tank and you will see the locking ring that holds the pump in place.

Disconnect the fuel lines and harness connector from the pump. Tap the locking ring counter-clockwise with a brass punch and a hammer to loosen it. The fuel pump can now be removed.

Disconnect the fuel lines

Disconnecting the fuel lines from the fuel pump can be challenging, but with the right tools and knowledge, anyone can do it. Before you begin, ensure you have the correct size wrenches and pliers to remove the lines safely. It is important to relieve the fuel pressure from the system by removing the fuel pump fuse and running the engine until it stalls. This will prevent fuel from spraying and causing a dangerous situation.

Once the pressure is released, locate the fuel lines and identify any clips or connectors holding them in place. Using pliers or a specialised tool, carefully remove the clips or connectors while holding the lines to prevent unnecessary tension. With the clips removed, use the wrench to loosen the fittings on the fuel pump and gently pull the lines away from the pump. Be aware that some fuel may spill out, so have a rag or container ready to catch any spills.

There are various types of fuel line styles, each requiring a different method of disconnection. For example, the push-type connector has different versions, some with a push point on both sides, requiring a push from both directions to release, while others only push from one side. The push-and-lock style connector is another type, which requires you to push it onto the fitting and then push the locking tab through. To remove this type, release the safety latch and push the connector back through.

Another style is the pinch-type connector, which has retainers on each side. To disconnect, pinch these together and then reinstall by either leaving the retainer on the male end or removing it once in place. The spring-style retainer fitting is installed by sliding it on until you hear a click. To remove, pull back on the black ring that serves as the release tool, and then pull the fitting off.

The process of disconnecting the fuel lines can be daunting, but by following these steps and staying focused on the task at hand, you can safely and effectively complete the job.

Install the new fuel pump

To install the new fuel pump, you'll need to follow a series of careful steps to ensure a proper installation and avoid any potential issues.

First, you'll want to compare the new pump to the old one and ensure they match. Sometimes, the new pump may look slightly different due to updates or improvements, but as long as it matches the specifications of your vehicle, it should be fine.

Next, you'll want to install the new seal ring and pump assembly into the fuel tank. This typically involves raising the tank just enough to reconnect the fuel hoses, electrical connections, and emissions hoses. You'll then raise the tank into place and reinstall any necessary components, such as the fuel filler neck and fuel tank straps.

It's important to note that you should always consult your vehicle's service manual or seek guidance from a professional mechanic if you're unsure about any part of the process.

Once the new pump assembly is in place, you'll want to reconnect the negative battery cable and fill the fuel tank as needed. It's important to ensure that the tank is at least one-quarter full before starting the vehicle to provide adequate fuel for proper pump lubrication and cooling.

Finally, you'll start the vehicle and double-check your work, paying close attention to any signs of leaks. If everything looks good and there are no leaks, you've successfully installed your new fuel pump!

Additionally, it's worth considering replacing related components, such as the fuel filter, fuel pump strainer, and fuel tank O-ring or gasket, to ensure optimal performance and prevent any potential issues.

Frequently asked questions