Fuel Line/Teflon Tape

bds85466

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I was told not to use teflon tape on the fittings going into the fuel pump. Is there validity to this? If so, why?:confused:
 

83Evinrude

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Re: Fuel Line/Teflon Tape

Probably due to the risk of bits of tape coming loose and getting stuck in the fuel system. Pretty sure I have seen the same recommendation in my Volvo service manual.
 

PiratePast40

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Re: Fuel Line/Teflon Tape

For the above reasons plus the fact that the seal is not on the threads but on the male/female flares. Teflon tape was developed as a thread lubricant not as a seal although it does help to seal when used with tapered threads (pipe threads).
 

CheapboatKev

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Re: Fuel Line/Teflon Tape

Is there a product that is recomended then?
Or do ya just give the fittings another little bit of torque?
 

PiratePast40

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Re: Fuel Line/Teflon Tape

Flare and compression fittings don't seal on the threads so putting anything on the threads isn't going to help. If the sealing surfaces are leaking then look there and not at the threads. Cranking down on the fitting may work but it may also exasperate the situation.

Don't get me wrong, teflon tape and pipe dope can certainly be useful on the right application.
 

ButchC

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Nov 11, 2007
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Re: Fuel Line/Teflon Tape

If the threads see fuel then don't use teflon. Go to an automotive store and look for a thread sealant that is designed for fuel. Permatex makes a thread sealant for this purpose.

Butch
 

robert graham

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Re: Fuel Line/Teflon Tape

When I installed my fuel/water seperator the instructions said to not use the teflon tape but to buy and use the teflon pipe thread compound that is white and comes in a tube. I did that and it seems to work fine. I do believe a little piece of that teflon tape could get loose in your fuel line and really plug up your system. With the compound there's nothing to get loose. Good Luck!
 

bds85466

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Re: Fuel Line/Teflon Tape

so this is confusing. Obviously flare fittings/adapters don't seal on the threads, yet pipe dope is recomended. Is this solely for lubrication purposes then?

Can you get the Permatex stuff at Napa? I'm trying to fix a leak going into my fuel pump that won't go away.
 

boat1010

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Mar 10, 2009
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Re: Fuel Line/Teflon Tape

Just like the other posts are saying.. The threads do not see fuel.. It is the flare that stops the fuel from leaking. Too much torque is just worse than not enough. If you tighten it too tight it will ruin the flare and never stop leaking. Then your only choice is to replace it. :(
 

a70eliminator

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Re: Fuel Line/Teflon Tape

If the fitting end that screws into the fuelpump itself has a pipe thread I would definately apply a thread sealant, but the flare end no for reasons already given.
 

bds85466

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Re: Fuel Line/Teflon Tape

yeah the flare/fitting junction is not leaky.
 

bds85466

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Re: Fuel Line/Teflon Tape

I bought some permatex form a gasket. I found that as I was torquing her down into the fuel pump that the female threads of the fuel pump casting was cracked -- probably where the leak was coming from in the first place.:)Lucky I have one on order arriving today...

anyone know how much you should torque these things as not to repeat the same mistake twice?
 

JustJason

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Re: Fuel Line/Teflon Tape

its tapered thread... so snug but not wicked tight.
 

Knightgang

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Re: Fuel Line/Teflon Tape

I bought some permatex form a gasket. I found that as I was torquing her down into the fuel pump that the female threads of the fuel pump casting was cracked -- probably where the leak was coming from in the first place.:)Lucky I have one on order arriving today...

anyone know how much you should torque these things as not to repeat the same mistake twice?

A torque number no, but I would shug it up to the point that it feels secure and does not leak, then maybe an extra 1/4 turn. I have a problem with overtightning as well from time to time. So I started the good and secure feeling plus 1/4 turn on most things and I have had no more problems...
 

bds85466

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Re: Fuel Line/Teflon Tape

I would shug it up to the point that it feels secure and does not leak, then maybe an extra 1/4 turn.

does not leak...

that's what I'm goin for.:cool:

kinda tough considering all you have to go through to make sure that doesn't leak -- reinstall fuel filter, line, and fittings! If it does you've gotta do it again!
 

Fishermark

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Re: Fuel Line/Teflon Tape

otherwise, crrrrack goes the casting?

It is easy to over torque a tapered pipe fitting. That is another reason the teflon tape is a "no-no" - it makes it too easy to over tighten the fitting. I recommend the Permatex fitting sealer.
 
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