66 Fuel inlet leak of 4160 Holley

[Jeffrey B.]

My small block 66 Corvette has a tendency to leak at the fuel line inlet on my Holley Carb. This always happens if I let the car sit for an extended period, like a month in the winter, then start it up. It seems like the carb fitting is what appears to be leaking. I always need to retighten the inlet fitting on the carb and also the fitting were the fuel line from the pump enters the carb fitting. I always lossen the line fitting nut, then the carb fitting itself. I then retighten the carb inlet fitting, then the fuel line fitting. Seems like the stainless steel line gets torgue built into it when I tighten it then when the car sits cold for awhile the torgue created on the stainless steel line from tightening the line fitting causes the carb inlet fitting to loosen, so it leaks the next time I start it after it has set for an extended period. It is anoying and a nusance, not to mention a fire hazard.
When I tighten the fittings then drive the car I always need to stop and make sure there is not a leak occuring. I can usually tell even when driving if I detect a faint odor of fuel coming back through the car. Not something a Corvette drive wants to experience. Need to pull over immediately, shut off the car, open the hood to check. The enjoyment of the driver has suddenly disappeared. Now I need to break out my tools along the road and tighten things up if there is even a slight hint of a leak.
This is the second time I have replace the hard line from the pump to the carb due to this problem. I know flared stainless steel lines can be difficult to seal if not lined up exactly with the carb inlet. I sometimes loosen the carb mounting nuts to give me some alignment flexability when I tighten the fuel line fitting, then retighten the carb mounting nuts.
Any suggestion on how to fix this problem for good would be greatly appriciated.
Thank You for taking the time to read,
Jeff

[Keith B.]

Re: 66 Fuel inlet leak of 4160 Holley

why do you need a S/S line? replace line with a carbon steel line as original, and replace the copper crush washer in the fuel bowl and enjoy your car

[Leif A.]

Re: 66 Fuel inlet leak of 4160 Holley

Jeffrey,
Get a stock steel fitted line and replace the stainless line you're currently using. Before installing the new line, remove the four hold down nuts on the carburetor first. Then when fitting the new fuel line to the carb inlet you can wiggle/maneuver the carburetor to more easily align the new fuel line fitting to the carburetor inlet. Get the fuel line installed and snugged...then re-install the four carb hold down nuts. Then, double-snug the fuel line. One more thing, tighten the inlet nut that holds the fuel filter in place first and then using a wrench to hold that nut, use a flare nut wrench on the fuel line nut behind the flare and tighten. On a new line, I usually tighten and then loosen the fuel line nut several times to help seal the new flare end.

[Joe L.]

Re: 66 Fuel inlet leak of 4160 Holley

My small block 66 Corvette has a tendency to leak at the fuel line inlet on my Holley Carb. This always happens if I let the car sit for an extended period, like a month in the winter, then start it up. It seems like the carb fitting is what appears to be leaking. I always need to retighten the inlet fitting on the carb and also the fitting were the fuel line from the pump enters the carb fitting. I always lossen the line fitting nut, then the carb fitting itself. I then retighten the carb inlet fitting, then the fuel line fitting. Seems like the stainless steel line gets torgue built into it when I tighten it then when the car sits cold for awhile the torgue created on the stainless steel line from tightening the line fitting causes the carb inlet fitting to loosen, so it leaks the next time I start it after it has set for an extended period. It is anoying and a nusance, not to mention a fire hazard.
When I tighten the fittings then drive the car I always need to stop and make sure there is not a leak occuring. I can usually tell even when driving if I detect a faint odor of fuel coming back through the car. Not something a Corvette drive wants to experience. Need to pull over immediately, shut off the car, open the hood to check. The enjoyment of the driver has suddenly disappeared. Now I need to break out my tools along the road and tighten things up if there is even a slight hint of a leak.
This is the second time I have replace the hard line from the pump to the carb due to this problem. I know flared stainless steel lines can be difficult to seal if not lined up exactly with the carb inlet. I sometimes loosen the carb mounting nuts to give me some alignment flexability when I tighten the fuel line fitting, then retighten the carb mounting nuts.
Any suggestion on how to fix this problem for good would be greatly appriciated.
Thank You for taking the time to read,
Jeff

Jeff------


As I've said many times before, while I LOVE stainless steel just-about-anything, I do not recommend its use for fuel or brake lines. For these applications the downsides of using stainless steel exceeds the upsides. Besides, the corrosion resistance properties of stainless steel are rather moot considering the use-profile of these cars and the life expectancy of most of us owning the cars.

[Timothy B.]

Re: 66 Fuel inlet leak of 4160 Holley

Jeff,

Get a steel line and also replace the bowl inlet nut. This inside surface can get a wear spot from the original line and not seal to a new line. The parts are cheap, don't fool around with gas leaks.

[Jeffrey B.]

Re: 66 Fuel inlet leak of 4160 Holley

To all, Thanks for the feedback. I will order a new fuel line non stainless steel. I bought a new inlet fitting and placed a bronze or copper flair saver in where the fuel line fits into the inlet. Not sure what the flair saver material actually consists of, but I tightened everything up and it has not leaked when starting and driving.

[Jeffrey B.]

Re: 66 Fuel inlet leak of 4160 Holley

Just to follow up on my previous post. The proper term I believe for the item I had installed is referred to as a flare gasket.