Replacing The Fuel Pump In Your Wrx: Step-By-Step Guide

Replacing the fuel pump in a WRX is a fairly straightforward process that can be completed in under an hour, even for those with limited tools and skills. The first step is to work in a well-ventilated area and to run the car down on fuel to avoid spills when opening the fuel tank. The rear seats must be removed by unbolting the bottom and top portions of the seat. This provides access to the fuel pump assembly, which is located behind the rear passenger seat. The fuel pump assembly is held in place by several bolts, which need to be removed. Once the assembly is exposed, the fuel lines and electrical connector can be disconnected, and the old fuel pump can be lifted away from its rubber cradle. A new fuel pump can then be installed, and the process can be reversed to refit the new pump.

How to Replace Fuel Pump WRX

Disconnect the battery and open all doors

Disconnecting the battery and opening all doors is a crucial step when replacing the fuel pump in a WRX. This step is important for safety and ease of access to the fuel pump.

First, make sure you are working in a well-ventilated area, free of any open flames, to mitigate the risk of fire or an explosion. Working near open doors will help ensure proper ventilation. Additionally, if you are performing this task outside, make sure your windows are up to prevent dust or debris from entering the vehicle.

Disconnecting the battery is a safety precaution to prevent any accidental electrical sparks, which could ignite fuel vapours and cause an explosion. It is also beneficial if your ECU needs to be reset, as disconnecting the battery will achieve this.

Before disconnecting the battery, it is recommended to unplug the green plug behind the passenger footwell trim and crank the motor for one minute. This will help relieve some of the pressure in the fuel lines.

Once the battery is disconnected, you can begin to safely open all the doors of the vehicle. This will provide you with the necessary access to the rear seats and trunk area, where the fuel pump is located.

With the doors open, you can now proceed to fold the rear seats and remove any necessary trim or panels to fully expose the fuel pump assembly. Remember to have rags or paper towels on hand to absorb any fuel that may spill during the disconnection process.

By following these steps, you can safely and effectively prepare your WRX for the fuel pump replacement, ensuring a smooth and secure process.

Remove rear seats and bracing

To remove the rear seats and bracing of a WRX, first locate the bolts for the cushion at the front of the seat, near your calves when sitting. Remove these bolts. Then, you will see bolts along the backrest, mounted to the car. Loosen these bolts and pull down the back seat. You can then tighten the bolts to secure the backrest.

If you have a 2016 WRX, the process is a little different. First, fold down both halves of the backrest. Remove the four plastic push-pins that attach the seat back fabric to the trunk area. Take out the two bolts that hold the short (driver's side) backrest to the center hinge, and lift it up and out. Then, remove the hinge from the floor and the other half will pull out in a similar fashion.

If you have a 2011 WRX, there are two hidden releases—little straight, black plastic bars about a foot from the doors, where the seat meets the floor. Pull them straight out toward the front of the car.

For a 2017 WRX, pull the tabs at the front of the seat toward the front of the vehicle.

Once the seats are removed, you can remove the bracing. Look for an ovalized metal cover on the passenger side, directly behind the folded seat. Remove this cover and the foam underneath to expose the fuel lines.

Disconnect electrical connector and feed hose

Disconnecting the electrical connector and feed hose is a crucial step in replacing the fuel pump in a WRX. Here is a detailed guide on how to do this:

Preparation:

Before beginning any work, ensure you are in a well-ventilated area, free from any open flames, for your safety and the safety of your car. It is also recommended to wear a proper respirator and to run your car down on fuel as far as possible to minimise the risk of spillage. If your fuel level is over half, be prepared for some fuel to escape when you open the fuel tank.

Accessing the Fuel Pump:

To access the fuel pump, you will need to remove the rear seats of your WRX. This involves unbolting the two 12mm bolts located below the seat and then rotating and pulling out the seat bottom. For the upper portion of the rear seat, you will find two or three bolts under the seat back that need to be removed. After removing these bolts, pull upwards on the seat back to remove it.

Disconnecting the Electrical Connector and Feed Hose:

• With the rear seats removed, you will now have access to the fuel pump assembly.
• Using your preferred pair of pliers, remove the spring clips on the hoses.
• Have a few towels ready to soak up any excess fuel as you remove the hoses.
• Disconnect the electrical connector by pressing on both sides of the orange portion of the connector to slide it off.
• Carefully remove the hoses, being aware that fuel may spill out.

At this point, you can continue with the rest of the fuel pump replacement process, ensuring you have a container or towels to catch any fuel spillage and being careful not to bend or damage any components.

Remove fuel tank cover/pump assembly

To remove the fuel tank cover/pump assembly, start by removing the rear seats. There are two bolts to remove for the seat bottom and four for the seat back. Once the bolts are out, rotate the bottom of the seat up and pull it out. You may need to lift the front of the seat bottom and rotate it out to get it out of the hooks holding it in place.

Next, remove the upper portion of the rear seat. There are two or three bolts under the seat back that hold it in place. After removing these bolts, pull upwards on the seat back to remove it. This part can be tricky as the upper seat back can get stuck in the brackets.

Now, remove the support brackets and noise isolation panel. There are eight gold bolts that need to be removed to take out the support brackets. The noise isolation panel is held on by plastic clips that can be removed with a trim tool.

Sitting on the passenger side, pull up the trunk carpet to expose the trap door for the fuel pump. Remove the four screws holding the trap door and the noise-isolating foam.

With the door and foam out of the way, you can now see the top of the fuel pump assembly. Disconnect the electrical connector and remove the spring clips on the hoses using pliers. Have towels ready to soak up any excess fluid as you remove the hoses.

Push all the connectors and hoses off and away from the hanger. Be ready to fight them as they will attempt to ruin your day when you try to pull the hanger out of the tank. Clean off the top of the assembly if needed.

Remove all the 8mm nuts that hold the hanger to the tank and carefully set them aside. Now, carefully remove the fuel pump and hanger from the tank. You will need to rotate the assembly as you pull it up to keep it from getting caught on the internal portion of the tank. Be careful not to damage the level float.

Place the assembly in a box with towels for easy cleanup. Disconnect the wiring connector from the pump. If you have an anti-surge tank, unclip the two halves and remove it. Then, remove the clip that holds the hose onto the fuel pump. Now, the fuel pump can be lifted away from its rubber cradle.

Remove the old fuel pump and install the new one

To remove the old fuel pump and install the new one, you will need to first remove the rear seats of your WRX. This is done by unbolting the two 12mm bolts located below the seat, then rotating the bottom of the seat up and pulling it out. There are hooks holding the seat in place, so you may need to lift the front portion of the bottom seat and rotate it out.

Once the rear seats are removed, you will have access to the upper portion of the back seat. There are two or three bolts under the seat back that hold it in place. After removing these bolts, pull upwards on the seat back to remove it. This part can be tricky as the upper seat back can get stuck in the brackets, so be persistent.

With the rear seats removed, you will now have space to remove the bracing that supports the upper rear seat. These are easily removed by taking out four bolts. Next, remove the small noise isolator by taking out the plastic clips with a trim tool.

Now you will have open access from the cabin to the trunk. You will see several support brackets and a noise isolation panel. Remove the eight gold bolts holding the brackets in place, then take out the push clips holding the noise isolation panel and remove it.

Sitting on the passenger side, pull up the trunk carpet to expose the trap door for the fuel pump. Remove the four screws holding the trap door in place, then take out the noise-isolating foam. With the door and foam out of the way, you will see the top of your fuel pump assembly.

Disconnect the electrical connector, then use pliers to remove the spring clips on the hoses. Have towels ready to soak up any excess fluid as you remove the hoses. There is also a quick-connect that can be tackled with a set of pliers.

Now you can remove the entire fuel pump and hanger from the tank. This can be tricky, as you will need to rotate the assembly to keep it from getting caught on the internal portion of the tank. Be careful not to damage the level float as you remove the assembly.

Place the fuel pump assembly in a box lined with mats or towels to transport it out of the car. To remove the old fuel pump, disconnect the wiring connector from the pump. If you have an anti-surge tank, you will need to unclip the two halves and remove it. Then, remove the clip that holds the hose onto the fuel pump, effectively holding the fuel pump down in the hanger. Now the old fuel pump can be lifted away from its rubber cradle.

To install the new fuel pump, first transfer the pick-up sock from the old pump to the new one. Then, place the new fuel pump into the cradle. Connect the electrical connector and the hoses, ensuring that all connections are secure.

Finally, return the fuel pump assembly to the tank, being careful not to bend or damage any components. Secure the assembly with the 8mm bolts, then replace the noise isolation panel, support brackets, rear seats, and carpet.

Frequently asked questions