Fuel Pump Fittings....Which Thread Sealant?

[53fatfndr]

Anybody know what I should use to seal the threads on my fuel pump fittings? I have an ever so slight seepage that needs to be taken care of. I'm using a Holley pump with barbed 3/8" fittings for both ports. Thanks for the help

[Henry Rifle]

I use teflon tape. However, keep it about three threads back from the inlet of the fitting, and don't let any of it get in the fuel line.

[53fatfndr]

Well, I have teflon tape on there now. I was told not to use that as the gas would eventually eat through it, and it has.

[Corvette64]

Aren't you supposed to use flare fittings on a fuel pump? You didn't say what motor you're runnning, or mechanical or electric pump, so I'm assuming we're talking mechanical. My chevy's have always been setup with a factory hose fitting on the fuel pump for supply from the tank and a flare fitting on 3/8" mild steel hard line to the top of the engine. I never run a soft gas line up the front of my cars. If I'm off base here just ignore.

[rumrumm]

You should not have to use thread sealant on fuel lines if you use the appropriate fittings. But if you feel you need to use something, use the teflon liquid sealant. Tape can raise havoc with your fuel lines.

[Itoldyouso]

I like the liquid teflon tape. It comes in a little tube like toothpaste, but smaller, and won't break off and get in the fuel system if you keep it back a thread or two.


Don

[Henry Rifle]

You should not have to use thread sealant on fuel lines if you use the appropriate fittings. But if you feel you need to use something, use the teflon liquid sealant. Tape can raise havoc with your fuel lines.

Point 1: Many of the most popular fuel pumps have NPT fittings on the inlet and outlet. If you use the appropriate fittings and don't use sealant, you will have leaks.

Point 2: Tape is like anything else, including the teflon sealant. If you use it correctly, it works. If you don't, it causes problems. Sure, a piece of tape in the line can plug things up. So can a glob of anything else. "Havoc" isn't unique to teflon tape.

[rumrumm]

Point 1: Many of the most popular fuel pumps have NPT fittings on the inlet and outlet. If you use the appropriate fittings and don't use sealant, you will have leaks.

Point 2: Tape is like anything else, including the teflon sealant. If you use it correctly, it works. If you don't, it causes problems. Sure, a piece of tape in the line can plug things up. So can a glob of anything else. "Havoc" isn't unique to teflon tape.

I agree. It normally states in the instructions that you get with such parts that sealant should be used. But with regular OEM fittings (especially brake fittings) you should not have to use any. Anytime you do it right, you should not have a problem.

[53fatfndr]

You did it wrong.

That's possible. Also, forgot to mention, it's a mechanical pump on a Ford 400. When I installed the fittings with the tape, I would turn the fittings until they were tight. After driving the truck, I checked everything over just to make sure there was no leaks. I put my hand down there and noticed it was slightly seeping. I was able to tighten the fitting quite a bit more, even though it was initially tight. So, I figured I might have used too much tape! Anyway, I went and reinstalled them today with the teflon liquid paste and noticed that the fittings sit a little bit deeper into the pump. I think that will work better.

[Henry Rifle]

Yep, hold it in your left hand, and wrap the tape clockwise. If you're left-handed, you're on your own . . .

[C9x]

I like the liquid teflon tape. It comes in a little tube like toothpaste, but smaller, and won't break off and get in the fuel system if you keep it back a thread or two.


Don

Loctite's LPT I think it's called, works fine on steel and brass.

Don't use it on aluminum.
It glues the aluminum together so strongly that you'll peel threads off the male fitting when taking them apart later on.
And later on can be ten minutes to several months.

Use Teflon tape as recommended.
It works well and the recommendations not to use it probably come from sloppy workers.
If you're careful you won't have a problem.

That said, the local speed shop recommended Never-Seize for use on pipe threads that are aluminum on both sides.
It works well.

Just don't crank it up so tight that you split a fitting.
With Never-Seize and Teflon tape, friction is lessened and it's easy to overtorque fittings.

[allengator]

I'm left handed and I have to think about it for a second or I will do it backwards everytime! lol.....

Tape is fine for fuel fittings if done correctly...