I recently installed a holley dual feed carb. The dual feed fuel line I have has a hex screw at the union of the two metal lines. It leaks!! Does anyone know what it is for? Can I use gasket sealant on the threads to stop it from leaking? Any help is appreciated.

thats a tough one. i know on no gasket sealants that gas won't eat through. there may be some that i'm not aware of. The ones that i know of that will hold are permanent and won't allow the line to be removed. i'm assuming the leak is caused by sripped threads. i haven't worked on a double pumper for years. are these internal or external threads? i know there are some expandable rubber fittings the work on internal threads as in quadrajet inlet lines. Try contacting peratex and holly and ask them for a recommendation.

Hey Steve , can you post a pic or give us a bit more info .

geo

Hi Steve, the hex screw is is just a plug for an optional fuel pressure gauge. Try taking it out, wrapping it with teflon thread tape and reinstalling it. The slippery properties of the teflon will allow it to be tightened more and will probably stop the leak. If not, your probably better off getting a new line. They are not very expensive. Summit Racing has a very nice adjustable one with a built in filter for about 35 bucks.
There are also several others out there for less. Good luck, Mark

Thanks for the info. It is for an optional gauge, I found pictures on the net of the same line with a gauge in the same spot. Will fuel eat through telfon tape though?

I have used teflon on my fuel systems for years and it has worked fine. If it allows the fitting to be tightened properly, it will not be effected by fuel.
Mark

I agree teflon tape would work as long as the threads on the fitting arn't too far gone. A tip for putting teflon tape on any fitting. Hold the teflon tape in your left hand and the fitting to be taped in your right. Roll object in your hand. Cut tape. Now the tape will be on the fitting in a direction as to not come off when theading it into the other fitting. (makes a neater job too)

Make sure teflon tape starts on TOP of the part you are applying it to. All this does is assure that the tape is applied in the proper direction so that as the part threads into the fitting the tape does not begin to back off, but rather is forced into and between the threads to seal.

I work in a shop that builds HVAC units that deal in thousands and millions of BTUH gas burners. Teflon tape is used constantly, so don't worry about the gas eating it away.

if you follow these directions "Hold the teflon tape in your left hand and the fitting to be taped in your right. Roll object in your hand. Cut tape. Now the tape will be on the fitting in a direction as to not come off when theading it into the other fitting" You will find that the teflon tape always in on correctly and turning the right way. try it and you will see.