Fuel Tap to Hose Adaptor Seal

davamb · Dec 11, 2014

Hey all,

have just bought new fuel taps and had to purchase adapters to mate to my fuel lines. What is the best way to seal the adapter to the tap? I'm wondering if Teflon plumbers' tape on the thread might be the best way to go or should I try and introduce an o-ring or fiber washer into the union?

gjr · Dec 12, 2014

Teflon tape is more of a lubricant than a seal. The fittings should make the seal themselves (between the threads, bubble, flare, what have you). If you are not getting a seal, you don't have the right parts yet.

Greg

concours · Dec 12, 2014

Those adapters are a spherical seat, fastened by a machine thread, no sealant should be used. Teflon tape is for sealing pipe threads. Are the adapters leaking?

JimNH · Dec 12, 2014

Teflon tape on the threads really doesn't help as the seal is metal to metal cone to seat. Having said that, I have found that if it's reluctant to seal at a reasonable torque, an almost nonexistent smear of pipe dope on the cone will fix it. I don't know if it provides lubricant to let the two parts find a better seat or if it's providing a seal at a molecular level and don't care. Don't get carried away; it only takes a little.

tomspro · Dec 12, 2014

concours said:
Those adapters are a spherical seat, fastened by a machine thread, no sealant should be used. Teflon tape is for sealing pipe threads. Are the adapters leaking?

I found the yellow (not white) teflon tape helps. Leaks before, none after. Done.

SteveA · Dec 12, 2014

Some of us..... racers I guess .....undo and refit these fuel connections all the time.....to play with carms and other stuff........ it would be a complete pain if you needed to use any form of sealer/sealant....

Like the man said, if they leak, you haven't got the right fitting yet.

RoadScholar · Dec 12, 2014

If your leak is between the petcock and the 5/16 OD pipe that enters your fuel line, you can lap the two surfaces together with some fine valve lapping compound; do clean all surfaces to insure that lapping compound does not enter the fuel system.

B.

davamb · Dec 12, 2014

Thanks guys,

here's the assembly (with token Tygon tube). They're not tapered threads so I don't see how the seal is going to be perfect.

auldblue · Dec 12, 2014

The spigot on the female pushes on the recess on the fuel tap and seals it tight. I have mine off and on all the time and they are far from new and the seal every time.

J

The cone shape fits inside the tap and Bingo!

davamb · Dec 12, 2014

Ahhhh! Now I understand. Thanks AuldBlue. I need a completely different style of fitting. Or something like a large ball bearing with a hole bored through it.

gtsun · Dec 13, 2014

Yes. It looks like you have the wrong fitting on you fuel line. The correct ones can be gotten from any good Brit bike place.. Try Old Britts, Oldbritts.com

concours · Dec 13, 2014

davamb said:
Thanks guys,

here's the assembly (with token Tygon tube). They're not tapered threads so I don't see how the seal is going to be perfect.

Loctite 567 seals the threaded tap to the tank bung very well. http://www.henkelna.com/product-search- ... 7960863745

The sealing washer does nothing to seal these threads, a mis-application. JMWO :lol:

Fuel Tap to Hose Adaptor Seal

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