View Full Version : DIY: Bosch 040 fuel pump install B5A4 1.8TQM

02-23-2015, 08:00 AM
Disclaimer: As always, myself, Audizine or it's associates cannot be held liable for any damages occurred while following these steps. DO NOT attempt a fuel pump replacement near any source of open flame. You will be hovering over the fuel tank so proper ventilation is necessary. If you are unsure of your abilities or are in a hurry then consult a professional. It is also helpful to have a shop manual for the vehicle you're working on. I use a Haynes repair manual from advanced/auto zone ($25). Take pictures at every step, it's a lot faster to reference a picture than to ask for help on the forum and wait for a response. Finally get your tank empty prior to starting. I waited until my low tank warning light came on and it everything was easy to get to without having to submerge my hand in fuel. Read this post in it's entirety before starting. If you haven't replaced your fuel filter yet, this is a good time to do that.

Tools required:
4mm allen key
7mm, 8mm, 10mm sockets/ratchet
1/4" worm clamps (3)
flat head/ phillips screwdrivers
rubber mallet/dead blow
shop vac
paper/shop towels

Optional items:
Audi basket removal tool
new fuel line from flange to fuel pump (not sure on the size)

Bosch 040 drop-in kit from 034 Motorsports
http://i947.photobucket.com/albums/ad316/LTcoastieR/Mobile%20Uploads/20150220_141955.jpg (http://s947.photobucket.com/user/LTcoastieR/media/Mobile%20Uploads/20150220_141955.jpg.html)

This took me roughly 2.5 hours to complete, if you bleed off the fuel pressure before starting and mark the direction of the basket while in the holder, you can do this under 2 hours. (Two mistakes on my part that were very time consuming).

First Bleed off the fuel pressure. Remove your fuel cap, this will relieve the pressure in the fuel tank, but not in the fuel lines. Next remove the fuse for the fuel pump (mine is #28) and try to start the car, it could start, but then stall; your fuel line has been bled. Turn the ignition off and remove the key. Now you are ready to work.

My fuel pump access plate is in the trunk, just aft of the passenger rear seat. I have heard that FWD, Avants or even 2.8s might be in a different location, like under the rear seat. Remove the 3 screws of the access plate and remove the cover.
http://i947.photobucket.com/albums/ad316/LTcoastieR/Mobile%20Uploads/20150222_132324.jpg (http://s947.photobucket.com/user/LTcoastieR/media/Mobile%20Uploads/20150222_132324.jpg.html)
STOP HERE! see how dirty the fuel tank access is? You DO NOT want this crap in your tank, spend the 15 minutes it takes to clean this; I used a vacuum, paper towels and carb cleaner.
http://i947.photobucket.com/albums/ad316/LTcoastieR/Mobile%20Uploads/20150222_132443.jpg (http://s947.photobucket.com/user/LTcoastieR/media/Mobile%20Uploads/20150222_132443.jpg.html)

http://i947.photobucket.com/albums/ad316/LTcoastieR/Mobile%20Uploads/20150222_134736.jpg (http://s947.photobucket.com/user/LTcoastieR/media/Mobile%20Uploads/20150222_134736.jpg.html)

Remove the fuel lines first, have some towels ready, there could still be fuel in the lines. If this is the first time these have been removed then you will need to replace the one-time clamps with a worm type clamp. My fuel return line had blue ink and the supply line had white ink.
http://i947.photobucket.com/albums/ad316/LTcoastieR/Mobile%20Uploads/20150222_135519.jpg (http://s947.photobucket.com/user/LTcoastieR/media/Mobile%20Uploads/20150222_135519.jpg.html)
Now the electrical connector is an absolute PITA, I had dentistry picks that I was able to get under the clips, I undid one side, then kept the connector tilted while I undid the second clip.
http://i947.photobucket.com/albums/ad316/LTcoastieR/Mobile%20Uploads/20150222_140635.jpg (http://s947.photobucket.com/user/LTcoastieR/media/Mobile%20Uploads/20150222_140635.jpg.html)

Now using a flat head and a rubber mallet (remember you're dealing with fuel vapors, so nothing that will make sparks), tap the tank flange retaining ring counter clockwise to remove it.
Pull the flange up and remove the tank level sending unit connector (take a picture of how this is connected, it can be connected in either direction and I'm not sure what will have if you get it reversed). Remove the full return hose, this is a little tricky, you have to squeeze the connector ring to remove it.
http://i947.photobucket.com/albums/ad316/LTcoastieR/Mobile%20Uploads/20150222_141535.jpg (http://s947.photobucket.com/user/LTcoastieR/media/Mobile%20Uploads/20150222_141535.jpg.html)
Be careful not to ruin the rubber gasket for the flange, I removed mine so I didn't damage it.

You can set this flange or cap aside (it will be in your way, I'm not sure if completely disconnection it would help because it will be a PITA to re-install it with the pump in the tank). Audi makes a tool to remove the basket, but I was able to reach in and turn the old pump which also rotated the basket. Before you start, mark the direction of the basket (take a picture) this basket only goes in one way. You need to rotate the basket 15 degrees counter clockwise to remove it.

Once you have the basket out of the car, take it to a clean work area for the swapping of the basket to the Bosch 040 fuel pump. You need a 7mm and 8mm socket to remove the wiring from the old pump, or you could just cut the wires after the connector (pay attention to which wire is positive and which is negative). Remove the one-time use clamp on the fuel line and pull off the line. You are now ready to remove the basket. Pry the clips from around the basket and remove the top from the bottom.
http://i947.photobucket.com/albums/ad316/LTcoastieR/Mobile%20Uploads/20150222_143908.jpg (http://s947.photobucket.com/user/LTcoastieR/media/Mobile%20Uploads/20150222_143908.jpg.html)
Adjust the ring on the 040 to the same height as the old pump you'll need a 4mm allen key. I chose to lower the ring an 1/8 of an inch, this will cause you to not have as much usable fuel in your tank, but will also lessen the possibility of sucking up sediment from the bottom of the tank.
http://i947.photobucket.com/albums/ad316/LTcoastieR/Mobile%20Uploads/20150222_151351.jpg (http://s947.photobucket.com/user/LTcoastieR/media/Mobile%20Uploads/20150222_151351.jpg.html)

http://i947.photobucket.com/albums/ad316/LTcoastieR/Mobile%20Uploads/20150222_144007.jpg (http://s947.photobucket.com/user/LTcoastieR/media/Mobile%20Uploads/20150222_144007.jpg.html)
Swap over the rubber mounts for the basket and install the new pump into the basket, it will only go together one way. At this point if you purchased a new piece of fuel line, install that now, otherwise reconnect the fuel line with a new worm clamp. Cut off the wire connectors if you haven't done so yet, strip the wires and install the new ring terminals supplied in the kit. The black wire on my old pump was positive and the brown wire was negative. You will need an 8mm and a 10mm socket to tighten the electrical connections (don't torque these down, it's aluminum, you can strip the threads; just until it's tight).
http://i947.photobucket.com/albums/ad316/LTcoastieR/Mobile%20Uploads/20150222_150046.jpg (http://s947.photobucket.com/user/LTcoastieR/media/Mobile%20Uploads/20150222_150046.jpg.html)

http://i947.photobucket.com/albums/ad316/LTcoastieR/Mobile%20Uploads/20150222_150408.jpg (http://s947.photobucket.com/user/LTcoastieR/media/Mobile%20Uploads/20150222_150408.jpg.html)
Now you're ready to re-install in the reverse order. Remember the basket will only go in one way, I hope you marked it or took a picture. My basket had a "V" cut into the top, that "V" was facing the fuel door. Make sure your float has full range of motion (no wires or fuel lines keeping it from moving). Once you have everything back together, put the fuel pump fuse back in and turn the ignition on, you should hear the fuel pump prime the line, if not something isn't together correctly. Lastly start your car, it could take a few seconds for the line to prime. Now go get some gas.