View Full Version : How to access broken gas-tank seal....

04-04-2007, 02:15 PM
I've read a couple of posts in both AZ and AW on people having gas leak issues after a fill-up and I am having the same problem. I was told that this seal can be accessed through the trunk and easily repaired. Has anyone done this and do you know how much the seal itself costs? Seems like an easy DIY job, but before i dive into the trunk to find the gas tank seal i was just wondering if anybody's done this before.

thanks for the help.!

04-04-2007, 04:28 PM
I have a 2000 A4 2.8 quattro. This job is REAL easy. I give it a 1 or 2 out of ten. Hardest thing is cutting off old clamps. Mine was accessed from the trunk.

You will need:
One seal as mentioned
Two new clamps (I chose screw on fuel injection clamps in the 1/4" size, I think)
Large flat blade screwdriver
Rubber mallet (or something to hit screwdriver with)
Tin snips or wire cutters
A few rags
White out or finger nail polish

Here's what you do (at least on my car):

1. Fold down rear passenger side seat (well, open door first)
1(a). Unhook battery cable under hood
2. Get in car and sit on folded down rear seat
3. Unhook cargo net in trunk
4. Fold up carpet on passenger side, starting from front to back.
5. You should now be staring down at a black cover with three screws about the size of a coffee can lid. Remove those screws
6. You will now be staring at an off white cover with a black ring around it, also about the size of a coffee can. There are two fuel lines coming out of this cover and an electrical connection. Remove electrical connection (you did unhook battery cable, correct?). Mine just pulled straight off
7. Now, the hardest part of this job, removing those crimp clamps. I used tin snips or wire cutters to cut them off. They are a bit of a bear. I cut mine off at that "hump" in the clamp (where the crimpers would go). Once that part is cut, pry them off with screwdriver, etc.
8. Once clamps cut off, arrange your rags around hoses and slide off. Use a flat blade screwdriver to apply force at the end of the hose. You'll see what I mean when you do it. Work the hose off gently. Some fuel will spill out (about 2 ounces or so) so use the rags to catch that fuel. Remove both hoses
9. Take your white out/nail polish and make two marks on the cover, the black ring around the cover, and the body of the car. There should be arrows on either the ring or the cover. Put your marks on these arrows and on corresponding locations on ring and body of car. These will be your reference marks so you know where to put the cover back on and how far to screw ring back on.
10. Now, take your large screwdrvier and put it on one of the ridges on that big plastic ring around the cover. Gently strike it (it may take a bit of force the first few times) to get the ring to unscrew. Once you get it unscrewed (about one full revolution), take it off.
11. Once ring off, pull up on cover gently. There are still electrical and fuel connections under that cover. Once cover off, remove rubber seal around the hole. Put in new seal.
12. Put cover back on using white out marks to reference correct position.
13. Put on black ring and retighten using hand/screwdriver until it is back in white out position.
14. Reconnect electrical connection on top of cover.
15. Using new screw on clamps (or crimp on clamps if you prefer) reattach fuel lines.
16. Put on black lid on top of cover and reattach with the three screws.
17. Hook battery back up.
18. You are DONE!!!

This may sound complicated, but it's really not. All these steps should take you no more than 20 minutes and it's all easily accessible. I can do this in about 10-15 minutes now because I know what I'm doing and have done it before.

I didn't proofread the above, so everyone please make corrections if I am wrong/mispelled words/got steps mixed up, etc.

Hope this helps!

04-04-2007, 10:11 PM
thank you so much! I will do this on the long weekend. This write-up should be posted somewhere. So i'm assuming I'll just ask for a 'fuel' seal, at VW/audi when buying it

cheers mate

04-05-2007, 08:11 AM
Thanks. I forgot the last steps, like "roll carpet back over cover" and "put passenger seat back up", but I figured that is pretty intuitive! :)) Hope it helps. Really, it is a very easy job. Have about 1/2 of gas or less. You can do it with a full tank, it's just that you'll be working in a bit of gas. The hardest part, really, is getting those crimp clamps off. They are easy to get to, just hard to cut off. Oh, and the black plastic ring that you have to spin off is hard to get started off, but once it starts to move it comes off. And when puttng it back on, look on the bottom of the ring and see where the "starter" spot is on the threads. Match that up with the "starter" spot on the cover threads and spin on about one full turn (just match up with your white out). It makes it easier to spin on if you match the threads.

This job is easier than spark plugs. Everything is right on front of you and you get to sit down during the whole operation. There is a write up on AW about the fuel pump that I used but wasn't exact for my car (it was for an A6 I think). I'd provide pictures, but once you sit down to do the job you'll see that you really don't need them. Although if you want pics, go to AW write up. It was helpful.

04-05-2007, 10:32 AM
Sweet. VW has the plastic ring for $15 and audi has it for $20, just another reminder that if you need to get dealer-supplied parts, getting them through VW is cheaper than AUDI most of the time if not all.

Thanks again orangedawg

04-07-2007, 06:40 PM
403, how did the install go? Any problems? Anything I missed? Hope it went well!

04-12-2007, 09:35 AM
Hey orange, finally did the ring replacement last night ...went to fill up the tank afterwards and for some reason it was still dripping as it usually was...I"m not too sure anymore if it was the original seal that was broken (although it was a little worn) cause originally when i took off the black metal lid cover, the whole cover that the fuel hoses were connected to were dirty as hell..is it possible i have a leak in my hose(s)? Was yours pretty dirty? Wish i took a pic, but i'm gonna dive in for a closer look this weekend.

04-12-2007, 01:44 PM
The top of my cover was pretty dirty. Really dusty and bizarrely had a bunch of bird seed on top of it (go figure). You might try driving around with the black/grey cover to the cover off (the first one you take off, has the three screws) and see if you can stop where it is dripping. Actually, you should be able to see the leak with the top cover off (again, the one with the three screws, not the one with the hoses on it) and the car running since the pump will be running. It could be a fuel line or perhaps the hose clamps. If you can't see fuel leaking from the seal, the fuel lines, or the clamps, the leak may be on top of the fuel filter at that top banjo bolt. Those are the only places I can think of where it could be leaking that you wouldn't be able to see obviously (like the lower banjo bolt at the bottom of the fuel filter).

How long did it take you? Did the instructions help? Good luck!

04-13-2007, 10:34 AM
Instructions given were awesome,.exactly what was needed to get the job done. I had a little trouble with the clamps but even more trouble putting the cover back on with the new seal. Took me about 45 min-60 min or...15 min to put the cover back on with the new seal..!

I'll try it out this weekend...I wonder why it only leaks when the tank is full...i should probably fill it up again this weekend so i know it will leak...

04-13-2007, 10:35 AM
thank again though...i'll letu know how it goes after i've checked it out this weekend