Fuel Leak

[squeak104]

I just finished installing the STM tank to rail kit. I bought the Earl's fitting 9894DBH to connect the -6AN line to the stock sending unit. But now I have a leak between the Earl's fitting and the line from the sending unit. Below is a picture of the fitting and my setup. Also there is a picture of the M14 side. Is it supposed to be flat on the inside? I've heard some talk through other threads of it being flared and such. Also Earl's says there is supposed to be an o-ring with the fitting but I did not a receive one.

I've read in other threads about using an o-ring or copper crush washer to seal it. But where would either go. I'm guessing that the tube nut on the sending unit is rusted to the tube since it will not budge or is this nut stationary?

I have tried just putting the -6 AN fitting directly to the sending unit without the adapter but it leaked worse. Please help, preferable with a picture. Thanks.

-clint-

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[ramsack]

this is probably the third edit. try this fitting. they use an inverted flare fitting which is supposed to spin free on the tube. that adaptor is for a metric pipe thread which is tapered, so it isn't even going in all the way. there is no crush washer or anything that will seal it and will probably not even get tight enough to crush anything to go in there. with that fitting in the link you just gotta cut off that fitting and use the blank tube. i would try to get the fitting free of rust first and spinning so you can cut it right at the flare and have plenty of tube to work with. also clean the tube of rust as much possible and make sure the inside is free of burrs or anything to restrict flow.

 

[Flash]

Don't you think it has something to do with the telfon tape you used? Fuel doesn't like teflon tape, and those fittings are not meant to seal on the threads.

 

[ramsack]

teflon tape or not it's a pipe thread on the adaptor trying to seal onto a flared fitting. but yea, flared fittings don't get teflon tape.

 

[squeak104]

Sorry I hadn't replied but I was able to get it to stop leaking. And after talking with one of my co-workers he told me about the whole not using thread sealant unless it seals by the threads. But if anything the thread sealant slowed the leak but was not causing the leak.

I fixed the leak with a fiber gasket down in the adapter fitting. I got the gasket from Home Depot. The gasket was kinda thin so I doubled it up. The gasket was 1/2" OD and 1/4" ID. 67 cents for two gaskets. My only concern was fuel eating the gaskets but its been two days and so far no leaks.

My co-worker used to work at a speed shop and gave me two other options for future reference. One was to cut the flare off and taking the tube nut off. Then slide on a tube nut and sleeve and re-flare it and that makes it into a -6 AN female. The other option would have been to remove the rest of the feed on the sending unit, weld on a -6 AN male, countersink the other side, and weld on a short piece of metal tube to clamp a short piece of hose to the pump. Not quite sure if there would have been enough room to do option two.

 

[ramsack]

yeah i wouldn't keep that gasket in there. i also wouldn't do that "making it AN with a new flare nut" either. i would do a welded fitting right on the plate type thing or that fitting i linked to in my post.

 

[squeak104]

What's wrong with the gasket? If the gasket would fail from fuel it would have by now. I drive a minimum of 50 miles a day, so the gasket would have seen plenty of gas by now. As long as the fuel doesn't eat it the gasket won't leak since it has been compressed, unless it becomes compromised by something else.

I personally was not too keen on the re-flaring option simply because of the condition of the line. But the same reason applies the fitting you linked too. A compression fitting on a slightly rusted line does not sound like a good idea to me. On a side note I'm not certain that that tube nut is supposed to rotate. When I removed the sending unit from my GST it did not rotate as well and the line looked almost brand new.

I also need to mention that I don't plan on leaving it like this forever. I few other expenses just came up so money is a bit tight so I was looking for the quickest and most inexpensive option that would work for a little while. When we get the other car going and have a little money to spend on the welding then I'll have it fixed properly.

 

[ramsack]

by that logic then no gasket would ever fail, but they do. is fuel something you really want leaking? either if the fitting rotates or not it is still an inverted flare. also unless the line is brittle it can be flared fine. this is why i said to clean the line if you use the fitting i sent you. i also used compression sleeves like that to patch up some piece of fuel line on my car without cleaning and it is fine. i just did more of a quick fix because i plan on getting the stm feed kit as well. the sleeve could also kinda be soldered or glued to the line as well. the sleeves were almost impossible to get on my new lines as well as my existing ones, so they are very tight without even being compressed.

 

[squeak104]

I have faith in it as well as my co-worker's advice that it will be fine. Like I said I don't plan on it lasting a lifetime. Gaskets can fail from an outside problem or time. Which is the case for every gasket on the car. Does that mean I shouldn't trust my headgasket? Or my injector seals? I know I'm reaching a bit but the same thought process applies. It may not say "fuel resistant" on the gasket I used but it doesn't mean it won't work. In general though I've never been a big fan of compression fittings.

On a side note I wouldn't recommend the kit, at least for a 2G. Being able to mount the filter where the stock one goes works well but doesn't leave much room for a fitting on the bottom of the filter. A 90 degree fitting on the bottom of the filter would have worked a lot better. Also a 90 degree for out of the filter would have been nice also to help it clear my intercooler piping (SSAutochrome FMIC). I think I ended up with about 3 ft of extra hose. Not much I can do about it now though so oh well.

 

[ramsack]

ya i just want to see you have a permanent solution cause it is fuel. my friend put the stm kit on his car and he ended up getting a different fitting near the filter cause it was a little weird with fitment. i do love the quality of the hose, and the lightness too. screw SS haha.