pipe dope on threads in fuel system

[kman67rsss]

i will be installing fuel lines in the next few days. i bought NPT to AN connectors. should i put sealant on the NPT threads, and if so what type.

[CoryM]

i will be installing fuel lines in the next few days. i bought NPT to AN connectors. should i put sealant on the NPT threads, and if so what type.

I wouls recommend againt using sealer. It can clog injectors. If the fittings are aluminum or brass (which they should be for fuel lines) the threads distort enough to seal without teflon. If you have to use sealer I would carefully use a little teflon tape. Be careful to not let any get inside the line though.
CoryM

[MrQuick]

I thought you were talking about something eles...on NPT, I like to use the paste but leave the first 2 threads dry as to not get the crap in the system. AN install dry

[Zefhix]

I wouls recommend againt using sealer. It can clog injectors. If the fittings are aluminum or brass (which they should be for fuel lines) the threads distort enough to seal without teflon. If you have to use sealer I would carefully use a little teflon tape. Be careful to not let any get inside the line though.
CoryM

WHOA, WHOA, WHOA!!!!! NEGATIVE!!! NO TEFLON TAPE!! That's what clogs the fuel system. It's a Holley needle-and-seat nightmare !!! He is right,though, the compression should seal but if you want cheap insurance Lockitite makes a liquid teflon in a tiny white squeeze tube with red writing. It's at your local Pep Boys/Autozone/Checker..etc. One word of advice is the cure time is more than they advertise always (or do I use too much...hmmmm). At least 24 hours is what you'll want to wait before passing fuel through...good luck.

[CoryM]

When I say carefully I mean it. I would use a single pass, as far up the threads as possible. Globs of teflon thread sealer (the liquid) will clog stuff just as fast as tape. I have seen that many times. I find it easier to control the tape and make sure its not going to enter the system. With soft fittings I dont use any sealer...... ever. If it leaks, its not tight enough or its NFG.

[Fuelie Fan]

I've had the tape show up in injectors as well, so you have to be very careful with it. There are two grades of tapered threads, normal and dryseal (NPTF). Look for the dryseal, this will increase the odds that it will seal without and thread treatment.

[KWIKND]

I am proud to say I used to work on a fleet of garbage trucks and we would use Permatex #2 non-hardening sealer. It is like your kids first poop in a tube but it works great. You can even turn say a 90 degree fitting past were it needs to go and back up and it will still seal. Try that w/tape and you will be tearing the whole thing apart later. We used it for everything, hydraulic 2500+ psi, engine oil and anti-freeze. You can get it at NAPA or most anywhere. Good Luck

Dan