I agree with the others that do not recomment teflon tape. If you feel the need to seal the threads, you may want to try a liquid thread sealer (not a thread locker) made for this type of application.
I used it on the fittings when I set up the 3x2 system on my hot rod, and it worked fine. Follow the instructions closely by not putting the sealer on the first few threads to prevent it from getting into the system. This product does not harden fully, thus providing a good seal.
I bought mine at NAPA - I believe it was a Permatex product.
I am installing a new fuel filter in my Vette, should I use teflon tape on the fuel fittings ??
Just to clarify, teflon tape does not belong on automotive application threads - period (as noted above).
If the threads are pipe threads (interferance type tapered threads), then used a teflon pipe thread sealant (which is a thick paste).
If the threads are typical fuel system flare fittings, do not use any sealant on the threads. The threads do not do the sealing - only the flared tubing does any sealing (to the opposing flare on the mating fitting), and should not need any sealant. It is acceptable to put a very, very small amount of anti-seize compound on the threads (for ease of assembly and disassembly later on).
Save the teflon tape for your house water pipes.
Last edited by Plasticman; 10-14-2007 at 12:47 AM.
NPT fuel line fittings require a thread assembly sealant.
AN flare fuel line fittings do not require anything but an anti-seize lube properly applied is nice to have.
The biggest issue with using teflon tape is in removal and reassembly. Once the fitting has been assembled, portions of that tape will become shreaded. Upon removal of that fitting more will become shreaded, and it is the removal of these shreads of teflon tape that are the root of the problem. Most guys do not take the time to clean out all of the teflon shreads properly (especially in the female portion of the threads). Then the fitting gets reinstalled, and these loose teflon shreads can become pushed into the tube/fitting where they will become a potential blockage (even in a cooling system).
Why use teflon tape, where it can cause a potential issue down the road, when there are better products that both seal and lubricate better?