Demon Carbuetors
Senior User
Joined: Jan 2002
Posts: 438
Likes: 0
From: Centreville USA
Well the other fuel line I bought from Mr. Gasket leaks as bad as the one from Demon. Demon asked me to check my fuel pressure which I did and it is running at 6 psi. Well within the normal range. So I have ordered from Summit Racing yet another fuel line (made by Demon) that uses flexible stainless steel braided lines and -AN fittings. The Demon guy said that these were virtually leak proof. We shall see.
Senior User
Joined: Jan 2002
Posts: 438
Likes: 0
From: Centreville USA
No, I can't see that they are. But I did notice that the Mr. Gasket leak is different from the Demon fuel line leak. The Demon fuel line is leaking between the tube and the retaining nut. The Mr, Gasket fuel line is leaking between the retaining nut and the adaptor nut. I have given up on the hard lines and hope that the braided stainless with -AN fittings I ordered from Summit Racing will work without leaks. I won't make the show this weekend as I had hoped, but there is another next Saturday. My fingers are crossed.
Senior User
Joined: Jan 2002
Posts: 438
Likes: 0
From: Centreville USA
Teflon tape should only be used on NPT (National Pipe Thread) pipe fittings. It should not be used on -AN or flare nut fittings. With NPT fittings the seal is provided by the fit of the tapered male threads into the mating tapered female threads. With -AN and other flare type fittings the seal is provided by the male and female flaired ends of the fittings themselves. The threads do not provide any sealing properties. If you have a leak with a -AN or flare fittings it is because the fittings are not mating properly and all the teflon tape in the world is useless. You are only creating a dangerous situation as eventually the leaking fuel will eat its way through the teflon tape. Ever dropped a piece of teflon tape into gasoline? The tape turns to mush.
Post Fiend
Joined: Sep 2000
Posts: 8,238
Likes: 3
From: Oregon
All true. And yet, for over twenty years I've been running them this way and have NEVER had a leak. The teflon doesn't totally turn to mush. 
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FE "Freakin Expensive"
Joined: Dec 2003
Posts: 6,461
Likes: 4
From: Smith Mountain Lake, VA
Well All I can say.is..I have been using teflon tape on all my Carbs..I just dont run it up that far on the threads to get it wet? never had a leak?? and I have run Holleys for 30+ years also? Russ
FE "Freakin Expensive"
Joined: Dec 2003
Posts: 6,461
Likes: 4
From: Smith Mountain Lake, VA
Well I dont think it would be to hard for the Carb Companies to use a harden seat inside the Carbs for there compression fittings!! that would assure a good seal!
JMHO...Russ
JMHO...Russ