Leaking fuel shut off valve question

[mll1446]

Have to replace fuel shut off valve it leaks into feul bowl. Nervous about threads in tank and taking old one out and if threads will leak with new one in. Or possibility of existing threads being damaged any suggestions. Thanks in advance

 

[Y-Blockhead]

Have to replace fuel shut off valve it leaks into feul bowl. Nervous about threads in tank and taking old one out and if threads will leak with new one in. Or possibility of existing threads being damaged any suggestions. Thanks in advance

The valve has ¼" pipe threads going into the tank. I use Locktite 592 on the threads going into the tank https://www.amazon.com/dp/B0002KKTH2/?tag=atomicindus08-20. Ensure the valve you install is the new "ball" valve type type that Snyder's sells along with a pencil filter. https://www.snydersantiqueauto.com/product.htm?pid=979339&cat=41707

 

[JayJay]

Ditto Y-B on using a pencil filter and thread sealer. I have used Permatex 59214 in the past, but lately I've been using Gasoila E-Seal with good results.

 

[mll1446]

Thank you

 

[katy]

Before you remove the valve, drain as much fuel as possible, then jack up the RH (passenger) side of the car about 4-6". This will cause any remaining fuel to migrate to the opposite side of the tank.

 

[JayJay]

Before you remove the valve, drain as much fuel as possible, then jack up the RH (passenger) side of the car about 4-6". This will cause any remaining fuel to migrate to the opposite side of the tank.

Downside with the pencil filter is that it adds about 1/4" more standing liquid after the tank is drained through the valve. I drain the tank as best as I can, then stuff rags down the tank inlet to sop up the remaining liquid fuel. Pull them out with a long handled needle nose pliers, or wrap some wire around the rags before you push them in. Put yer stogie aside while yer doing this...

 

[Y-Blockhead]

The valve has ¼" pipe threads going into the tank. I use Locktite 592 on the threads going into the tank https://www.amazon.com/dp/B0002KKTH2/?tag=atomicindus08-20. Ensure the valve you install is the new "ball" valve type type that Snyder's sells along with a pencil filter. https://www.snydersantiqueauto.com/product.htm?pid=979339&cat=41707

Additional info from post #2. Before Snyder's offered the new ball valve I got tired of the original type shut off valve leaking so I installed a second valve, which is a ball valve, to my gas line. it never leaks. I just have to reach farther. If I ever have it apart again, I will move the ball valve to connect to the original valve. I didn't think about it until I had it together...

 

[mll1446]

Thanks for help old fuel shutoff came out new one screws in 1 1/2 turns then stops . Ideas?

 

[JayJay]

Thanks for help old fuel shutoff came out new one screws in 1 1/2 turns then stops . Ideas?

That is a tapered fitting, designed to get progressively tighter as you screw it in. So it should not stop dead. Silly question, but are you attempting to screw it in with the handle in the "off" position, in which case the handle will likely hit the tank as you screw it in and stop it? (Don't ask how I know that.)

You could try very gently chasing the threads in the tank with a 14-27 NPT tap. Your goal is to clean the threads of any leftover threadlocker that may have been installed in the past. If you get high resistance, STOP, at that point you may be removing metal, and risk breaking the thread socket loose from the tank. You should also very closely inspect the threads on the male end (the valve) to be sure there aren't any burrs on the threads.

Are you using any of the lubricant/thread lockers discussed earlier? What you have is a steel-to-brass joint, which without some sort of lubricant can gall the brass and make it hard to make up. I try to always use the proper lubricant on tapered fittings.

1-1/2 threads does sound like a quite tight fit. A lot of making up tapered fittings comes from feel and expertise (you gain expertise by making mistakes, and you accumulate mistakes by experience...). Ask around and see if you can find someone who can help you. But please don't force anything, if you force beyond what it can take there is no way it will end well!

Good luck.

 

[katy]

That is a tapered fitting, designed to get progressively tighter as you screw it in. So it should not stop dead. Silly question, but are you attempting to screw it in with the handle in the "off" position, in which case the handle will likely hit the tank as you screw it in and stop it? (Don't ask how I know that.)

You could try very gently chasing the threads in the tank with a 14-27 NPT tap. Your goal is to clean the threads of any leftover threadlocker that may have been installed in the past. If you get high resistance, STOP, at that point you may be removing metal, and risk breaking the thread socket loose from the tank. You should also very closely inspect the threads on the male end (the valve) to be sure there aren't any burrs on the threads.

Are you using any of the lubricant/thread lockers discussed earlier? What you have is a steel-to-brass joint, which without some sort of lubricant can gall the brass and make it hard to make up. I try to always use the proper lubricant on tapered fittings.

1-1/2 threads does sound like a quite tight fit. A lot of making up tapered fittings comes from feel and expertise (you gain expertise by making mistakes, and you accumulate mistakes by experience...). Ask around and see if you can find someone who can help you. But please don't force anything, if you force beyond what it can take there is no way it will end well!

Good luck.

Ditto