Diesel leaking around the outlet on the tank

[marioxp]

Again I have a problem with diesel leaking around the outlet on the tank. I tried to solve it with Hylomar M paste before, but as you can see from the picture, it didn't last long. It seems to me that Hylomar M paste is not good for places that have more movement.

Would some sikaflex compound stick it well?

It seems to me that constant fuel pressure on the outlets requires a stronger adhesive.

[Yngmar]

I don't think Sika has any product for sealing fuel tanks. Loctite 577 is a fuel/oil resistant thread sealant, that may or may not work - I don't know what these fittings look like on the inside, got a picture with one removed? It's not an adhesive, so the fittings need to be mechanically fastened by some other means and prevented from rotating even slightly - then it'll be fine.

Hylomar M is a non-hardening and non-setting gasket maker, not suitable for this even though it's fuel resistant. Loctite 577 does set hard.

[tiger79]

I don't know what these fittings look like on the inside, got a picture with one removed?

I believe they're just nitrile rubber bungs which are a push-fit into the hole in the tank.  Then, when the pipe fitting is inserted, it compresses the bung against the hole.

Here's a pic of a pack of them, they're usually called "return bushes".

[Yngmar]

Thanks. Ours were brass nuts fitted into the tank. With these, I'd be tempted to renew them. Might be the rubber is worn or cracking.

[Lazy Pelican]

We had a B36 2004 and the outlet from the fuel tank leaked from new. The problem was that the hole in the tank had been drill on the ‘skew’ (not parallel) so the contact between the bung and tank was minimal. Our solution was not to brim the tank which seemed to work.

[marioxp]

I don't know what these fittings look like on the inside, got a picture with one removed?

I believe they're just nitrile rubber bungs which are a push-fit into the hole in the tank.  Then, when the pipe fitting is inserted, it compresses the bung against the hole.

Here's a pic of a pack of them, they're usually called "return bushes".

Yes, mine looks the same.

But, locally I can't find it.

[SYJetzt]

If you are in croatia give the guys from pitter bodul in biograd na moru a call, they are bavaria spare part dealers. If they don't have them on stock, they can order it for you!