Leaking fuel filter O-rings, did I get the wrong fuel filter?

I replaced my fuel filter today in my '99 beetle with this: http://tdiparts.com/catalog/product_info.php?products_id=421

Upon restarting, I get a pool in the lip of the fuel filter pretty quick (but not like spraying or even a fast trickle). So I double checked the o-rings, the new ones look the same as the old. Put both of them into the little notches. Still more leaking. Took off all hoses, checked for cracks, found none. Tried bending it too to see if any opened up, seems fine.

Finally out of desperation, I put all four o-rings, new and old on. The new ones are in the little notches where they should be. The old ones are both at the top of the tee. I push it in as far as I can and force the mickey mouse clip into place.

Now there is very little leaking. But still a very small pool forming in the lip after a few minutes of driving. Not enough to seep down the side of the filter.

So, did I get the wrong filter with too wide of an inlet such that the o-rings don't seal?

The old one was a Mann WK 853/3 3-310.

Hold on, when I took the tee off the old filter, the fuel was not up to the top, not even over the filter element. Does the filter actually fill the whole way with fuel up to the o-rings? Are those o-rings supposed to prevent fuel leakage under pressure, or just act as an air seal?

Maybe I do have a fine crack that I couldn't see in the tee.

Well, I put the old filter back on with just the two original o-rings. It still leaks very slowly so I must have cracked the tee. I just hope it's not both the tee and the o-rings because doubling up those o-rings did slow the leak quite a bit.

I had a problem with with leakage on my Beetle once too. You have the tee pushed all the way into the filter right? It takes a little force. And you're putting the cover and retaining clip in the right way? I also positioned the filter in its bracket on the high side so it would have a tendency not to pull out. You've used new orings, so that can't be it. What's the deal with the different colored o-rings anyway? Are they really different? I still have the same T. I never had any problems except for that one time, knock on wood. You're not nicking an oring when installing, are you?

It was all about the tee. I got a new one off Metalman and all is well. I'm really glad he lives near me.

Cool. It sounded like you got a lot more fuel leaking than I did too. It's amazing how stinky even a little gets.

Isn't it special-I changed the fuel filter this morning and now it too leaks at the T, a lot! I should've known better not to do it since I had to go somewhere this afternoon - a Mets game at Shea, (found workaround , thank goodness). $40 bucks, not in stock, two days. Great.

You sure you got both o-rings out? And the new ones on the T correctly? They are different sizes.

I got both o-rings out, but the rings that came with the Meyle filter were both black and they looked the same size. I never could see the size difference in the blue and black rings each time I changed the filter over the course of the car's life. Perhaps I'll pick up a new OEM filter when I'm at the dealer. That's if the FILTER is not a SPECIAL ORDER, lol.

Yea, mine is also leaking slightly at the tee and is starting to get grimy. I just thank 40 dollars is a lot for a little plastic piece.

Then again, 210,000 miles on that little plastic piece isn't that bad.

Hmm, I think I have the same problem. Just changed my fuel filter and there's a small amount of fuel leaking from the T. This fuel filter had the flange for the 'T' bent a bit, (Not sure if it was my fault or it came like that... it did come out of the box while in the back seat of my car...) I had to bend that flange back so the T and the clip would fit into the fuel filter. I'll have to go inspect it, but it looks like maybe I need a new one...

rampage said:

Hmm, I think I have the same problem. Just changed my fuel filter and there's a small amount of fuel leaking from the T. This fuel filter had the flange for the 'T' bent a bit, (Not sure if it was my fault or it came like that... it did come out of the box while in the back seat of my car...) I had to bend that flange back so the T and the clip would fit into the fuel filter. I'll have to go inspect it, but it looks like maybe I need a new one...

Click to expand...

Weird, it seems like my leak just stopped. Maybe the T wasn't fully seated and driving it a bit caused it to seat properly? Has anyone else ever seen that? It probably also has something to do with the fact that I bought a new $25 spare fuel filter (just in case I couldn't get the leak fixed...) Oh well, I guess now I have one for next time...

I just bought my TDI a month ago and it leaked when i got it, after fuel filter was replaced only 5k before. My leak was pretty bad, as it filled up the top of the filter in a matter of seconds. I replaced the o-rings as a local v-dub shop gave me them for free....same leak same rate. So i ordered the 20k kit from dieselgeek since i figured i'll need all that stuff sometime anyway and it came with a new tee.

All i did was take the tee from the new fuel filter and put it into the filter already in the car....fixed the leak.

The thing is though that even inspecting the old tee i couldn't find any cracks or anything, yet it WAS the problem. So yea it sounds like you just need a new plastic tee.

I just changed my fuel filter today and i got NO leaks what-so-ever.( or air bubbles in the line) Car seems to fly along now. Did the coolant at the same time and flushed out the rad, it came out a horrible orange colour. Half an hour of flushing to get it clear then topped up with a nice pink G12. Car gets warmer quicker now even in the cold weather we have got here.