stlbluesbrother

I bought a new fuel line that runs from the fuel pump to the carburetor. How should the connection to the fuel pump be prepared? I noticed some gasoline at the connection after trying to start the car. Incidently, I was told to not use teflon tape on the threads as it could disintegrate and get into the fuel over time.

Thanks

Rickman48

Although many say teflon tape is a no-no, I've been using it for years w/o a problem.
I just make sure it's ONLY on the threads, with NO overhang onto the seating surfaces of the metal line.
Stay a thread or two away from the starting thread, and I aways start any steel line by hand.

jensenracing77

that is a flair fitting. there is no need to use any sealer there. the seal is made at the flair from pressure from the nut squeezing them together. if there is gas at the fitting either there is something wrong with the flair or it is not tight. thread sealer will not fix the problem. if it stops leaking from a thread sealer then it is only masking the problem.

Lady72nRob71

On these, the flair at the end of the tube makes the seal. thread sealant here does nothing.
On that leak, just tightern a litle at a time with a line wrench. If it is tight already, it is possible the tube was not straight out when the fitting was first tightened.

stlbluesbrother

Thanks for the replies. I'm pretty sure I didn't tighten it down enough to gain the formed seal. I was a little apprehensive to overtighten due to potential misalignment.

I'll tighten it down some more.

joe_padavano

By the way, it's a FLARE fitting.

And as an example of why it's useless to use teflon tape or sealer on the threads, how does sealer on the threads prevent leaks where the tube passes through the flare nut? As others have correctly noted, the metal flare of the tube seals against the mating flare of the fitting. Technically, these are called inverted flares, since the threads on the flare nut are male. The 37 degree flares used on AN fittings are regular flare nuts, since they have a female thread.

Mike77

AND on brake lines it's called a double flare. A flaring tool "flares" out the tube end, then another die folds the flare lip over itself inward and is flared again. So if you need to re-flare the tube make sure it's right. Brake are one thing not to screw up.

Mike

jensenracing77

i know, i can't spell. i never could. the problem with spell check is that i spell so bad sometimes that i spelled another word and it don't catch it.

hookd on foniks workd four me

BlackGold

Two comments on poor seals for the pump-to-carb hard line:

First, I have yet to see a reproduction line for this spot which is bent correctly. (My experience is with 1970 442s. Other years/applications might vary.) I've seen some where there's no way they could ever connect, even with massive massaging. And I've seen others where the two ends will hook up properly, but the bends in between are not as the factory did it. Regardless, it only takes a small mistake in the flare end's "approach angle" to make it difficult to achieve a seal. There's not a lot of flex built into a line this short.

Second, I hope you didn't buy stainless steel. Stainless is rather hard, which makes it even more difficult to squash the flare to achieve a good seal.