Frank06

Hi All,

Noobie here with my mother-in-laws '99 A4 wagon(1.8 turbo) that has a gas leak from the area of the fuel filter (front of tank on passenger side.) This has been around on-and-off for awhile and now that I'm driving the car it's decided to rear its ugly head again. At first I thought it was the sealing washers not working right as that's where the leak appeared to originate, so I did a minor tightening (which didn't help) so ended up replacing the whole filter. There's still a leak and it's getting worse: I'm suspecting a cracked banjo fitting or perhaps the fuel line itself where it enters the banjo. It appears to be okay for 5 minutes of running then the leak appears. Is it hard to change the OEM gas line (this is on the inlet side of the filter.)

Ideas, tips, etc. appreciated. A friend who works at NAPA told me about a GM fuel-replacement kit that allows for an inline filter. I'm thinking about sealing off the banjo line to see if it leaks under fuel pump pressure but haven't yet done so.

TIA

Frank

turbo510

Did you change the banjo fitting's washers when changing the filter? The originals often won't seal the second time around. Another place to look is at the fuel line connections at the top of the tank, under the access cover. It could be fuel running down the tank from there.

I'd pull the fuel pump fuse, start the engine to release pressure, then carefully clean all around that filter. Put the fuse back in, and have someone start the engine while you watch the filter with a bright light. You should then be able to home-in on where the gas is coming out.

Frank06

Hi -

Yes I changed the sealing washers. I did that originally with the old filter canister as that's where the leak seemed to be. The sealing surface on the old fuel filter wasn't that great so I put the new canister in.

Is it hard to drop the tank all the way down? I've had it "levered" down to get better access to the fuel filter (what a stupid place to put a filter!) but don't know what else has to be done to drop the tank all the way.

thanks

turbo510

What do you mean "drop the tank"? I don't have an A4 wagon but we do have a Passat wagon; I would expect the filter arrangement to be similar, and there's no need to move the fuel tank on the Passat.

Frank06

If the leak is indeed in the banjo fitting at the bottom of the filter (inlet) and I change the gas line from the tank I'm assuming I'll have to completely lower the tank for access.

footyboyack

Frank,

I went through exactly what you are right now a few months ago, and I feel your pain. Firstly, although it seems obvious, make sure you have a copper washer on either side of each banjo fitting. Next, just know that the two fittings ARE going to be pretty tight (at least in my case) in order to achieve a proper seal; I ended up - against my better judgement, as the threading is aluminum and WILL STRIP - using an impact hammer on the inlet side in order to stop the fuel weep. With age, the lines also become easily crack-able and must be treated with relative care while intact, as doing a splice is misery (been there), and the OEM replacement will doubtless be overpriced. If you do decide to go the OEM replacement route, I can't help you too much having not done it myself, but would suggest you do a bit of sleuthing up top, beneath the access door hidden under the luggage carpeting. I would imagine a little ingenuity would allow you to snake a new line from the top down. Only go this way if you have reasonable doubt as to the degradation of the line, however. Make sure you have some solid torque on each of those banjo bolts, too; they're not 17 and 19mm (heads, that is) for no reason. Really try to pinpoint that leak, as turbo suggests.

P.S. Frank's right about prying the tank down on his model, turbo. There's not really another way.

Frank06

Thanks for that - good info. I'm in the process of making sure the banjo fitting itself doesn't leak by sealing it off but am having minor issues sealing the threads, etc. If I can prove the fitting or line into the fitting isn't cracked then I can concentrate on the filter/banjo interface. I'm glad I've got a few days to work on this but it shouldn't be this hard!

Frank06

Well, I demonstrated that the banjo line is okay, holding pressure for awhile. I annealed the washers again, and ended up replacing the new filter with ANOTHER new filter (I could feel the threads starting to let go in the original replacement) and still, it leaks. I noticed some "pickup" (cold welding) on the face of the banjo bolt and cleaned that up the best I could. That's where the leak is (still) coming from so I'm going to change the banjo bolt.

Can anyone point me to an online Audi parts outlet? Microfiche resource?

Thanks everyone.

turbo510

If you are going to reuse the old washers by annealing (which I've done) make sure they are flat and scratch-free on both sides. I just used a sheet of fine aluminum oxide sandpaper, on a piece of glass.

For online parts I usually use autohausaz.com

Frank06

I ended up calling the local dealer and ordering a banjo bolt and will pick up some new sealing washers when that comes in. What a PIA! Oh well, things could be worse!