Fuel Leak - Help

[Dougie B]

Hello all,

First post after joining and it is for help!

I have a 1993 525 SE Saloon which has developed a leak at the tank.

I jacked the car up and the leak seems to be coming from a fuel line ontop of the tank. This is the line that comes from the filler passes to the back of the tank (Back of car) and then appears to go over the stepped tank and back out and around the tank.

Is this the same line or does onego into the tank top and the other out? Hope I am making sense here!

Can someone show a picture or a diagram of the fuel pipe layout at the tank. It is a plastic tank.

Any help is really appreciated and thanks in advance.

Dougie B

[632 Regal]

you can get to the fuel pump from inside the trunk to see if its loose at that point.

http://www.realoem.com/bmw/partgrp.do?model=HE23&mospid=47406&hg=16&fg=05
http://www.realoem.com/bmw/partgrp.do?model=HE23&mospid=47406&hg=16&fg=10

http://www.realoem.com/bmw/partgrp.do?model=HE23&mospid=47406&hg=16&fg=15

[Kev]

I replaced my fuel lines several months ago on my '93 525i touring and it sounds to me like there could be a leak in your fuel tank vent pipes .If you have a rust belt car like mine then its pretty likely. There are 2 vent pipes[item 2&3 in realoem plastic fuel tank diagram] that run from the upper surface of the 'flat' part of the fuel tank(1 along the front edge and 1 along the rear edge) to the expansion tank . The expansion tank is tucked way up in the rear wheel arch next to the filler neck.
You'll need to remove the fuel tank to access the vent pipes. This involves: 1.accessing the top of the fuel pump/ sender unit from the trunk floor and disconnecting the supply and return fuel hoses - label them ;
2. removing the right rear wheel and plastic wheel arch covering to access the expansion tank & disconnecting the 4 hoses -2xfuel tank vent pipe, 1 main vent pipe and 1 thicker hose that runs directly to top of tank near fuel pump assembly. Be very careful if you decide -as I did- to disconnect the thicker hose at the tank end. It looked like it would be pretty easy to break off the plastic nozzle? on the tank itself!
3. removing the fuel tank support straps and lowering the fuel tank ( I used a floor jack & piece of board)- removing the rear bumper made accessing the support strap bolts easier but it might not be absoloutely necessary.
As for new parts, the vent pipes should be available from the dealer and they weren't that expensive . Alot of the hose clamps on the vent pipes are of the single use variety -I got conventional clamps from my local friendly stealer as replacements.

Hope this helps.

[Dougie B]

Hi Kev,

Thanks for that, it is really helpful.

Dougie