Leak at Fuel Rail fitting

[byeboy]

1997 850R: This fitting has seeped upon re-assembly before, and was cured by simply tightening the flare nut...This time, however I have resorted to "way too muck",tightness, and it still seeps. Pulled it apart carefully checked the flared inlet line for cracks or imbedded particles. It is not cross threaded, the double flared fitting looks perfect...I know the seal is at the flare, and not the threads, so I'd probably just be making a mess by trying pipe sealant or tape, and the fuel would simply move up the line and out the top, right?

How have you fixed this problem?



It doesn't seep much, but will produce a drip in less than a minute...and while I'm messing with this, I notice that my fuel pressure is very low (will give me an anemic little 'gush" when I crack the fitting, but no "squirt") (Oh, Great!! )

[jimmy57]

Are you sure it is the threaded flare and not the o ring in the end of the rail?
Nothing wrong with trying plumber's tape on the back side of flare and on the threads to capture it. I really like teflon pipe sealant in the tube.

[byeboy]

Yes, it is coming down the threads. The picture doesn't show it good enough, but the threads have fuel seeping down them. When you say "on the back side of the flare", do you mean wrap some tape around the hard line before sliding the nut down? (I've never tried that!)
When using the Teflon in a tube, do you likewise apply it also "upstream'?

[jimmy57]

Yes, exactly. On the line so the back of flare inside the nut will seal as that is a an exit not sealed by sealing the threads.

[byeboy]

That seems to have done the trick (I used tape). I'll take it on about a 50 miler now, so that should tell for sure! Many Thanks again for taking the time to help, JImmy!

[volvoman52]

I had never used Teflon tape on a flange fuel connection. But it sure fixed the leak!!! Did just as described. Thanks for the information!