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'99 Bonneville - fuel line leak at tank/connector

Posted: Sun Jan 15, 2012 2:05 pm
by gapman789
Another problem with this $1000 steal of a deal. First a $1000 tranny repair/replace and now a fuel leak....

I've a fuel leak in one of the lines at the grey connector/coupling where it connects to the metal fuel line near the tank, and next to the right rear wheel. The leaking line also is the one that goes to the in-line fuel filter along the frame rail. -Just trying to give an idea of where the leak is....

I have researched quite a bit on this.
Here's what I know:

The leak is a small drop at a time, until I touch the line at the connector and move it a little, then it pours out.
I understand there is an O-ring(s)in the connector. I am familiar with this type of fuel line connection, as they are the same style as on my motorcycles where the fuel line connects to the fuel pump and throttle bodies.

Does this sound like a simple O-ring replace and repair? Or could there be something more? The lines aren't rusty, car is a one owner and very clean.
I also read that there are different types of of rubber that the O-rings are made of....I'll do the search again to find out, but in the meantime, can someone point me in the right direction on what O-ring is compatible with fuel?

One more question and the one I'm most concerned about....The leaking fuel is only the fuel that is in the line, correct? When I disconnect the fuel line at the connector, the entire gas tank isn't going to drain out is it? I'm somewhat certain that it won't, but just making sure before I do it.

Thanks in advance.

Edit: Viton is the type of O-rings I just read...

Re: '99 Bonneville - fuel line leak at tank/connector

Posted: Sun Jan 15, 2012 4:12 pm
by RPACODY
gas tank won't drain out but make sure you bleed off the fuel pressure with the schrader valve on the fuel rail before you start. if you need more than o rings look into a fuel line repair kit - have seen them at Summit but i think they need to be spliced in

Re: '99 Bonneville - fuel line leak at tank/connector

Posted: Sun Jan 15, 2012 4:28 pm
by gmman
just had a similar experience except my leak was at the filter end of the line.

well, turned into an nightmare.

first i thought i would simply replace the o rings at the filter end. but, i could find no kit online or at the dealer for said o rings. then, i searched for gas proof o rings. found that nitrile and viton are supposed to resist gas damage. so, tried replacing o rings with the gas line still connected to the tank. first of all, i did get the old o rings out but, there are three separate o rings. first o ring is yellow, followed by something i will call a semi rigid plastic o ring and lastly the third o ring is orange/tan. the plastic o ring is deformed trying to get it out and appears to not be re-useable. and to my knowledge there is no such thing available at parts stores or dealer as a repair item.

so, i gave up on trying to repair the leaking filter end of the line and decided i would remove the entire line and replace with a new line. well there is no completer new line available except from the dealer at $100 plus.

that was the first problem. try as i might i could not get the original line to detach from the tank. the space is to small to get my finger into. so i purchased every type of line disconnect i could find. AND. none of them would work in the confined space.

i was able to find the dorman line repair kit which has the correct quick disconnect attachment and 3/8 inch line. the correct part number is 800-58 and is available at Advance Auto. make sure to get the "straight" line and connector. i cut into the existing line about half way to the tank and using the supplied barb, connected the repair line. says to heat both lines in water before connecting or to use motor oil. tried both and the heating in water gave best results.

going on about a week and no leaks. why did i not drop the tank to disconnect the line you ask. it was absolutely full, my luck. also to answer one of your questions, gas did not syphon out the cut line except for residual drops (i had previously released pressure in the line at the fuel pressure release valve under the hood).

Re: '99 Bonneville - fuel line leak at tank/connector

Posted: Sun Jan 15, 2012 4:29 pm
by 00Beast
It sounds to me like bad o-rings. You'll need the tool to pop the line off, I don't know the size, probably 3/16.

You can either remove the pressure at the rail or run it with the fuel pump relay till it dies. There will still be plenty of fuel in that line, so have a pan ready for it.

Re: '99 Bonneville - fuel line leak at tank/connector

Posted: Sun Jan 15, 2012 7:58 pm
by gapman789
gmman, thanks. Fuel line fixed. Went the Dorman repair kit route...It was a sonofagun to get that upper clip off. I could not get the disconnect tool on the line to remove the connector. I just kept after it for an hour or so until I finally got it with my fingers.

I wasn't able to get the new line on the metal connector as far as the old line, but it's on about 75%. Don't see how it could leak. Those connectrions are tight.

That part number for the Dorman repair kit at Advance for future reference is 800-058. It took some time for the sales guy to figure it out over the phone.

Thanks to all.