Audi A4 B7 – In Tank Low Pressure Fuel Pump Replacement

Introduction

Starting with the B7 generation, Audi went with direct fuel injection and that means there are two fuel pumps on this vehicle. There is the traditional low pressure pump that is in the fuel tank and there is also a high pressure fuel pump mounted on the engine. This guide will show you how to replace the in tank low pressure fuel pump. We went with a VDO branded pump which is owned by Continental and the part arrived in a Continental box. “Made In Germany” was stamped on top of the pump. Cost of the pump at the time of this article was $190. The fuel pump will have three ports on top of it – a fuel intake line, a fuel return line, and a third port. Our original pump also had the third port but it was internally blocked. The third port was not blocked off on the new replacement pump and that is why the fuel line cap had to be purchased. The cap blocks off that third port. We recommend you take a look at your old pump first to see if the cap is needed. If you don’t block off that third port, there is a risk of fuel fumes escaping through that port.

Removing The Rear Seat Cushion

Step 1. Let’s start by disconnecting the negative battery cable (yellow) from the battery. Use a 10mm socket. Also locate the high pressure fuel pump (red).

Step 2. If the car was driven recently then the fuel line will be under pressure. It’s best practice to relieve the fuel pressure before disconnecting the fuel lines at the in tank pump. Use a screw driver or similar object to press the schrader valve on the high pressure fuel pump (yellow). Have a rag under the valve to catch whatever gasoline comes out.

Step 3. The rear seat cushion is clipped into place so to remove it, just grab each side of the cushion and give it a quick pull upwards. It should become free. Do not remove the seat completely just yet – there are several electrical connector that have to be disconnected first.

Step 4. Disconnect the electrical plug on the left side of the rear seat cushion (yellow)

Step 5. Disconnect the two electrical connectors on the right side of the rear seat cushion. Now you can lift and remove the rear seat cushion out of the car.

Removing The Low Pressure Fuel Pump

Step 6. On the passenger side of the car, locate the access cover and remove the three phillips screws (yellow). Remove the access cover – you may need to gently pry it up.

Step 7. Here is a shot of the top of the in tank fuel pump. If you have never replaced your pump before then there will be a lot of dirt and debris here. Now would be a good time to vacuum up any junk around the area. You don’t want anything to fall into the tank when the pump is out.

Step 8. This part is a little challenging the first time you do it. Grab a flat-head screwdriver or a pick. The goal is to remove the two fuel lines. You will see blue tabs on each line. On each side of the line, press the blue tab using the screwdriver or pick (yellow arrow). Then while pressing, pull up on the line (red arrow). It takes a little bit of practice to do this simultaneously from both sides. It also helps to push the line down before pressing the tabs. This ensures that the inside of the blue tabs is not stuck on anything.

Step 9. Repeat the steps for the second fuel line. Have a rag nearby to clean up any spilled gasoline.

Step 10a. Disconnect the electrical plug for the fuel pump. There is a simple trick to disconnecting these connectors. First, push down on the whole connector. This ensure the clip is not stuck on anything inside. Then pull back the black tab (yellow). While pulling on the black tab, pull out the whole connector. See below for a better explanation.

Step 10b. Here is a shot of the connector – on the left notice the inside clip in the center of the connector. On the right, the black tab is pulled and you can see the clip lift up in the center.

Step 11. Now both of the fuel lines are disconnected along with the electrical plug. Next step is to remove the metal ring that secures the pump. Use a flat head screw driver or a punch (pictured above). Locate a grove in the metal ring and with a hammer, tap in the direction of the yellow arrow. This will rotate the metal ring counter clockwise. Important! – Mark the position of the metal ring – you will want to reinstall it in the same position.

Step 12. Remove the metal ring.

Step 13a. Now you can remove the fuel pump. Grab the top of the pump and pull up. Make sure to move the fuel lines out of the way as you pull up on the pump. It’s a good idea to tie off the electrical plug so that it doesn’t get in the way.

Step 13b. Here is the top of the pump coming up.

Step 13c. As you pull up on the pump you will notice that the top section separates from the bottom. This is ok because you will need to reach inside the tank and disconnect two more lines. See below.

Step 14a. On the bottom portion of the pump, disconnect the two additional fuel lines (yellow) and (read). The line marked yellow has two tabs on the connector that you push on while pulling at the same time. The line marked red just need to be pulled out. I did notice that it took some force to pull out that line.

Here is a shot of all four fuel lines.

Step 15. This is the fuel pump removed. Keep in mind that the white bucket is still full of gasoline. Notice the orange rubber seal. You will have to keep that and reinstall it with the new pump.

Installing The Low Pressure Fuel Pump

If you bought the VDO/Continental pump then there are no modifications required to make it work. It’s a direct fit part. Remember to grab the orange seal and reuse that. The replacement fuel pump consists of the top green half which moves up and down using the two metal rods as guides and the bottom portion that has the white tank. Take a note of where those metal rods are installed. Now separate the green top from the bottom just like in step 13c. Why separate them? It’s the only way that you will be able to reconnect the fuel lines you disconnected in step 14a.

Lower the bottom portion of the pump into the tank. Connect the two fuel lines in step 14a. Push in both lines until you feel them click into place. Now lower the top portion, making sure to place the two metal rods in the right position.

Push the top green portion of the pump down. The top of the pump can only be install in one position (red). Connect the remaining two fuel lines and the electrical plug.

Here is a shot of the cap that we needed to buy. It is installed on that third port on top of the pump.

Here is the final photo of everything installed and connected. Reinstall the top access cover and the rear seat cushion.

Note: I had an issue after reinstalling the pump where my gas gauge read lower than what I had in my fuel tank. If you have the same issue then the float arm (see photo in step 15) is getting caught up on something and not reading the right fuel level. I had to lift the pump up a second time, and manually move the float arm in the fuel tank to make sure it moved freely. After reinstalling everything for the second time, the fuel level read correctly.