How to Replace a Fuel Pump

Automotive fuel pump assembly.
Automotive fuel pump assembly. | Source

Replacing a fuel pump can easily cost you a fortune in repairs; depending on your vehicle make and model, you can expect to pay a mechanic $400 or more.

No wonder you want to do the job yourself. Or perhaps you just like doing repairs on your own car.

In fact, you may already have the tools you need for the project, because, in most cases, you only need some common tools. Except on a few vehicle models, which have components that block access to the fuel tank, the average car owner can do this job at home.

Yet, in spite of all these points in your favor, it's not recommended that you work on the fuel system of your car unless you take the proper precautions (more on this later). Other than that, of course you can do it.

Now, the level of difficulty will vary depending on your skills, experience, and the specific vehicle model you own. On some models, for example, replacing the fuel pump is a matter of removing a seat; in others, you need to raise the car and drop the fuel tank to access the module with the pump.

This guide is here to help you replace the failed pump in your vehicle, whether you need to drop the fuel tank or not. Although general in nature, for many car models this guide is all you'll need.

Here, you'll find important helpful pointers—and safety advice— along the way.

Let's start.


Ten Golden Rules to Follow When Replacing a Fuel Pump

I. How to Relieve Fuel System Pressure

II. How to Remove the Fuel Pump

III. How to Install the Fuel Pump

IV. How to Replace an Inline Fuel Pump

Always support the vehicle on jack stands when working underneath.
Always support the vehicle on jack stands when working underneath. | Source

Ten Golden Rules to Follow When Replacing a Fuel Pump

Here are points you need to pay attention to before you start working on your project. Your success may depend on it, so ignore it at your own risk.

  1. If you know you have to drop the tank to replace the fuel pump, drain as much fuel as possible out of the tank. Some tanks come with a drain valve. Or use a hand siphon hose and a fuel-approved container for this. Trying to lower a fuel tank even half full is just asking for trouble.
  2. Always support your vehicle safely with two jack stands if you need to drop the tank. A jack wasn't made to support a vehicle for long periods at a time. Play it safe.
  3. Select a place with good ventilation to work. Fuel vapors travel fast and are not healthy to breathe.
  4. Make sure you have enough room to move around your vehicle.
  5. Choose a place with a level surface if you need to lift your car.
  6. Don't work near appliances with open flames like dryers or water heaters. Fuel vapors are highly flammable.
  7. Of course you already know not to smoke near the fuel tank. Right?
  8. Have all the necessary tools on hand, including the disconnect fuel line tool if your model requires it. Check your car repair manual. You can buy this tool at most auto parts stores.
  9. If your vehicle has automatic ride control (ARC), turn off the air suspension switch if you need to lift your vehicle (see your car owner's manual), otherwise you may damage the system.
  10. When buying your new fuel pump, use the vehicle make, model, year and its VIN number. Keep in mind that your new pump may not look the same as the original if it's been replaced by a more efficient unit. But check that the new pump has the proper fuel line and electrical connections for your vehicle make and model. On some models, you can only replace the complete module, which includes the pump. Consult your car owner's manual or vehicle repair manual. If possible, wait until you have removed the pump assembly to buy the new unit to make sure you get what you need.

The Schrader valve is similar to the air valve on a bicycle or car tire.
The Schrader valve is similar to the air valve on a bicycle or car tire. | Source

I. How to Relieve Fuel System Pressure

Before you can start working on the fuel system of your vehicle, you need to relieve the pressure in the fuel system. If you need more information about relieving fuel system pressure for your car, or If you have difficulty locating any of the parts or components described below, consult the car owner's manual or vehicle repair manual for your specific model.

Depending on your particular vehicle model, you can use one of the methods described below:

  • Most fuel injection fuel system models (most modern vehicles) use a Schrader valve (similar to a tire's air valve). You can find the valve near the fuel rail, which holds the fuel injectors. Use a shop rag to cover the valve and a small screwdriver to depress the valve. Catch the squirt of fuel with the rag. Then disconnect the battery negative (black) cable.
  • Another method is to remove the fuel pump fuse (in the fuse box) or the fuel pump relay (under the dashboard or under the hood), or unplug the ignition coil electrical connector. Then start the engine, and let it stall. Crank the engine for a few seconds, and then disconnect the battery.
  • Some vehicles (specifically Ford) have an inertia switch (check your car owner's manual or repair manual). You can unplug this switch, start the engine. Let it stall. Then crank the engine for a few seconds, and disconnect the battery.
  • If you have a car with an access door to the fuel pump under the back seat or inside the trunk, start the engine, then unplug the electrical connector. Let the engine stall, and disconnect the battery.

After properly relieving the fuel system pressure, remove the fuel filler neck cap to relieve pressure inside the tank as well.

Removing the fuel pump assembly from the fuel tank.
Removing the fuel pump assembly from the fuel tank. | Source

II. How to Remove the Fuel Pump

Now, you are ready to start working on your fuel pump. First, locate the fuel tank in your vehicle. You may find the tank at the rear, under the vehicle, behind a body panel or under the rear seat. Check your vehicle car owner's manual or repair manual, if necessary.

  1. Some vehicle models provide a fuel pump access door, to save you from dropping the fuel tank to service the fuel pump. So check your car owner's manual or repair manual. Or check under the back seat or the trunk of your car for a small, bolted door. You may see an electrical connector on it.
  2. If you find the access door, unplug the electrical connector and use a ratchet with an extension and a socket of the correct size to remove the bolts holding the door in place. Keep the door bolts in a safe place, so that you don't lose them, and remove the door and look underneath. You should see the top section of the fuel tank where the fuel lines connect to, along with an electrical connector as well.
  3. If your vehicle doesn't have this access door, safely secure the car on a couple of jack stands.
  4. Block each front wheel with a wooden block to prevent the vehicle from rolling.
  5. Before proceeding to work on the fuel tank, check that no parts or components will interfere when you are attempting to drop the tank. Otherwise, remove these components. Check your car repair manual if necessary.
  6. Then, place the floor jack under the fuel tank with a piece of wood between the jack saddle and the fuel tank to prevent damaging the tank. Raise the jack just enough to rest the jack's saddle against the fuel tank.
  7. Then, proceed to remove the bolts from the two fuel-tank holding straps (some tanks use mounting screws around the flange instead). You may need to use a ratchet with a long extension to reach these bolts—and a swivel joint in some cases, to reach the bolts from an angle.
  8. Once you've removed the straps out of the way, check to see if you can disconnect the fuel filling hose or fuel lines from the fuel tank at this point. Sometimes you need to lower the fuel tank a few inches to gain access to these hoses. On some models, you'll need a fuel disconnect line tool to separate the fuel hoses.
  9. Before disconnecting any hoses or lines, you may want to tag them so that you have a proper reference when reconnecting everything again. You can use masking tape for this.
  10. Disconnect the electrical connector from the tank. This connector powers the fuel pump inside the tank. Look out for those fragile locking tabs that hold the connector in place.
  11. After disconnecting the fuel lines and unplugging the electrical connector from the tank, drop the fuel tank. Cover the any hoses you disconnected with a piece of clean plastic and secure it with a rubber band to prevent contamination. Depending on your particular model, you may not have to actually remove the tank out of the vehicle. Check to see if you can lower the tank just enough to remove the fuel pump or fuel sending unit assembly.
  12. Thoroughly clean the top of the fuel tank, especially the top bracket of the fuel pump assembly. This will prevent contaminating the fuel tank with dirt and foreign matter after removing the module.
  13. To remove the fuel sending unit assembly from the tank, unscrew the cam lock ring securing the assembly to the tank. Use a brass punch (or wooden dowel) to avoid sparks that may ignite fuel fumes. You can also use a screwdriver for this, but place a shop rag between the screwdriver and the lock ring tabs to prevent sparks. Use the punch or screwdriver to rotate the lock ring counterclockwise to release it. NOTE: On some vehicles, screws hold the fuel pump module in place. So you'll need to unscrew the bolts to remove the module.
  14. After removing the cam lock ring, slowly lift the fuel pump sending unit assembly. Underneath the sending unit mounting bracket you'll see a seal—rubber ring—around the opening of the fuel tank. Make sure to remove this ring and use a new one.
  15. You'll need to lift the sending unit out of the tank at an angle, so the long wire arm holding the fuel level float clears the opening without damaging the electrical mechanism connected to the arm.
  16. The sending unit assembly will only fit in the tank in a single position. Look which direction the long arm points to; you will need to reinstall the assembly with the long arm pointing in the same direction.

New fuel pump.
New fuel pump. | Source

III. How to Install the Fuel Pump

Once you have the fuel pump assembly out of the fuel tank, place it on a workbench or suitable working space so that you can install the new pump in the assembly, unless you are replacing the whole unit.

  1. Examine the electrical wiring, hoses and overall condition of the assembly. If necessary, replace the assembly; otherwise, it may affect the operation of your new pump and you'll need to redo the same job in the near future.
  2. Detach the fuel pump by disconnecting the bottom bracket, fuel pump strainer, electrical wires, and fuel outlet hose from the pump.
  3. Install the new fuel pump in the assembly, and reconnect the wires, hoses, new pump strainer and bracket.
  4. Clean the inside of the tank with pressurized water to remove dirt and let it thoroughly dry before reinstalling the new fuel pump assembly.
  5. Clean the fuel tank opening with carburetor cleaner before positioning the O-ring or rubber seal.
  6. Install the assembly with the new fuel pump in the tank along with a bracket-assembly seal gasket. You may want to apply a thin layer of petroleum jelly to the bottom of the rubber seal to hold it in place as you lock the sending unit onto the tank.
  7. With the pump module in place, lock the cam ring by rotating the ring clockwise using the brass chisel or screwdriver and hammer (or bolt the unit in place).
  8. Then, use the floor jack to lift the fuel tank just enough to reconnect the fuel lines, pump sending unit electrical connector, and filler neck to the tank.
  9. Carefully lift the fuel tank into position, making sure not to squeeze or damage the fuel lines and electrical connectors.
  10. Secure the tank by attaching the tank straps or flange mounting bolts.
  11. With the fuel tank in place and all hoses and electrical connectors plugged in, lower the vehicle, if you had to raise it. Or reinstall the access door.
  12. Connect the negative cable to the battery.
  13. Start the vehicle and check for leaks.
  14. If you have not changed the fuel filter in more than a year, this is a good time to install a new one. That way your new pump will have a clear path to fuel the engine.
  15. Refill the tank with enough gasoline to cover the fuel pump—usually a quarter of a tank full.

The next video gives you an idea on how to replace a mechanical fuel pump.

IV. How to Replace an Inline Fuel Pump

Replacing an inline (external) fuel pump is much easier than installing an in-tank fuel pump because you don't have to drop or gain access to the fuel tank.

In some vehicle models, you'll find the inline pump inside the engine compartment; in others near the fuel tank. In the later case, you will still have to raise the vehicle and safely support it on jack stands. If you don't know where to find the external pump in your vehicle, consult your car owner's manual or repair manual for your particular vehicle model. Whichever model you have, the next steps will help you replace your fuel pump.

  1. Place a container under the pump to catch the residual fuel in the lines.
  2. Use a regular wrench to hold the fuel pump fitting while using a line wrench to disconnect the fuel line from the fuel pump. Make sure to use a line wrench (aka flare wrench); if you damage the line nut, you'll need to replace the whole line.
  3. Disconnect the fuel line on the other side of the fuel pump.
  4. Unscrew the bolt holding the pump mounting bracket in place.
  5. Remove the old fuel pump
  6. Remove any gasket material from the pump mounting surface using a plastic scraper to prevent damaging the surface.
  7. Apply a thin layer of gasket sealer to the new fuel pump gasket and place the new gasket in position.
  8. Position the new fuel pump in place and secure it with the pump bracket.
  9. Start connecting the two fuel lines to the pump by hand first.
  10. Hold the pump fitting with a regular wrench, and tighten the line with the flare wrench.
  11. Tighten the other fuel line.


Learning how to replace a fuel pump is easy; learning how to work safely is something else. It's easy to let yourself skip safety steps to save time. But that's the worst mistake you can make when working on your car. Don't do it.

And two final pieces of advice:

  • To keep your new pump working at optimal conditions and extend its service life, always replace the fuel filter at your recommended manufacturer interval, or at least once a year.
  • Never run your car with less than a quarter of a tankful of gas. Fuel helps to keep the fuel pump cool, and the higher the fuel level in the tank, the lower the stress on the pump during operation.

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