zymurgist

OK, I'm hoping that I can do the "first crank" on my engine this weekend. I'm looking at the fuel pump/fuel line connection and there is a brass elbow with pipe threads that go into the fuel pump (AC Delco) and a female flare fitting on the other side that connects to the carb fuel pipe.

My questions:

1. Do I need any Teflon tape on the pipe threads? The factory didn't use it. How tight should I crank this fitting down? (I have the original but I plan to replace it since the flare seat looks like it's damaged.)

2. I assume that I don't need any Teflon tape on the flare fittings since the seal is accomplished by the use of the flare. Correct?

Jvette73

Defnitaly dont need tape on the flare fittings. You are correct in that the flare makes the seal. On the pipe fittings its not nessisarly needed if you thighten it enough. If you do use teflon tape make sure not to let any of it get into or across the the opening thru the fitting.

Eddie 70

I used teflon tape. That was a mistake. It leaked and I never could get it to quit leaking. I took the tape off and it hasn't leaked since. That is my experience.

77Dream

If the gas comes in contact with the teflon tape it would just eat through it anyway. At least thats what I guess it would do (since i'v never actually done it). Just tighten it down pretty snug and it should be fine.

zymurgist

Thanks guys...

I figured I might not need the tape on the pipe thread end... after all, the factory didn't use it. The reason I asked in the first place is that I had fuel leaks after I replaced the fuel pump (that was on the last motor :D ). I wasn't sure whether the leak was coming from the flare end or the pipe thread end. Now that I've got the elbow off, I can see that the flare end appears to be damaged. I'm guessing that's what caused the fuel leak... so I'm going to buy another elbow and take it from there. (Already bought a brand new stainless pipe which goes to the carb.)

Jvette73

Like i said its not needed. The pipe threads are tapered get slightly larger as they go. So long as you tighten it enough it will seal. :iagree:

zymurgist

Actually, the thought had occurred to me... I used Teflon tape that was spec'ed for use with gasoline. But I'd rather not use it at all if it's not necessary.

isosceles

Not knowing any better, I used the regular teflon tape that plumbers use. I haven't had any leaks, but must've got lucky tightened it the right amount.

warhovs

No tape (I used to work in design engineering for a fuel pump company). :)

zymurgist

Hmmm... I tried that and still got a leak. Tightened the brass fitting one more turn and the pipe threads seemed to seal but I had to use so much torque that I deformed the opening for the flare side (ever so slightly, I could still thread the flare nut into place).

Thinking of starting over with a new brass fitting... should I use anything at all in the threads to keep it from binding as I torque it down? The last one I tried, I used nothing at all in the threads.

GR8T WYT

Try using Permatex brand thread sealant, it is not affected by gas. Get it at most any auto parts store (Autozone) Make sure it's sealant and not antisieze.
Should do the trick.

ZD75blue

No tape...

But if you bugger up the threads on your Qjet... the yello teflon tape stuff is gas safe!

zymurgist

That Permatex sealant... is that the same stuff that one uses to seal up the threads of water pump bolts? I already have a jar of that in my garage.

GR8T WYT

No, but I guess the thread sealant could be used on any bolts. It comes in a hi-temp and hi-strength types.
Permatex PN. 56521 (hi-performance)
PN. 59235 (hi-temp)