How do I stop leak in fuel line?

Texas Tom

Texas Tom

Senior Member
My fuel line is leaking at the bowl connection and at the carburetor connection. It's a newly purchased line.

I'm thinking the ferrules are not seating correctly. They slide easily onto the tubing. Shouldn't they adhere tightly to the tube? If so, how do I achieve that tight fit?
 
Tom,
On the initial tightening, rub a little vaseline on the ferrule & fitting, then tighten firmly with a tubing wrench the first time until the ferrule grips the tube like a wedding ring on a fat man's finger! Skinny Bill W.
 
The ferrules should be snug. Maybe they, or the tube, are the wrong size, or maybe you're inserting the tube too far, or maybe the mating surfaces in the sediment bowl and carb are scratched up or otherwise damaged.

I would take the tube and the carb to a good hardware store or local auto parts store and ask someone to show you what you need to do. Hopefully, the same fix will work at the sed. bowl.

Steve
 
i wrap a "little" fuel approved teflon tape profesionally installed so nothing gets into the fuel system on the rounded ferell only not the threads. the ferell is what seats in the housing on both ends. as a side note the line should not extend more than 3/16 past the ferell or it can restrict the fuel flow and cause driveability issues.
 
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steve s said:
The ferrules should be snug. Maybe they, or the tube, are the wrong size, or maybe you're inserting the tube too far, or maybe the mating surfaces in the sediment bowl and carb are scratched up or otherwise damaged.

I would take the tube and the carb to a good hardware store or local auto parts store and ask someone to show you what you need to do. Hopefully, the same fix will work at the sed. bowl.

Steve
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Steve, am I NOT creditable?
I just told him how to do it. I was sqeezin' ferrules afore' lots of folks were BORN!:eek: Bill W.
 
You are probably aware that modern gasoline will dissolve most types of teflon tape.

If the brass sleeve doesn't fit on the fuel tubing pretty tightly, you'll not get a good seal. You can enlarge the fuel tubing or shrink the brass sleeve. Much easier to enlarge the fuel tubing!
 
I understand that there is a fuel-proof teflon tape now available, though I haven't sen it. I have always used a piece of string drawn through Ivory soap and wrapped around the threads to stop pesky leaks like this. Though if you have the conditions that Steve describes, this won't work.
 
Like Bill said, the first time you will have to tighten the nut very tight using a tubing wrench in order to squeeze the brass ring tight to the steel tube. It takes more force than you'd think, plus I'm not fond of these new one piece fittings where you tighten the brass nut until the brass ring breaks loose from the nut. Once it's tight, then the next time you remove it you won't have to go so tight.

In fact even better than a tubing wrench just use a 6 point box wrench to do the first tightening of both nuts, then remove one end to remove the wrench, and use a tubing wrench to tighten the nuts.
 
Teflon tape has always work for me. Leaving it back a few threads. I run ethanol free gas now. Might question "new" stuff on the tolerances in thread fittings. Wish i didnt.
 
Kind of depends also where you place the new line when you start tighten also. I find it better to keep the line out a smidge from seat before tighting. Hey or not.
 
P.S. said:
You are probably aware that modern gasoline will dissolve most types of teflon tape.

If the brass sleeve doesn't fit on the fuel tubing pretty tightly, you'll not get a good seal. You can enlarge the fuel tubing or shrink the brass sleeve. Much easier to enlarge the fuel tubing!
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With all due respect, Paul,
The brass sleeve or ferrule can only be "shrunk" by tightening it firmly, that's how it was designed. There is no proper way to "enlarge" the tubing.
Someone also mentioned that the new type fittings with the "break away' ferrule was a problem. If they are lubed well with vaseline & tightened down very tight at installation, they work perfectly. With a tubing wrench, tighten them until it feels "tight" then, with your hand on the end of the wrench, push down slowly & firmly & you will "feel" it "give" more as the ferrule compresses on the line.
Not tryin' to be a smart ***, I've been doin' this crap for what seems like EONS!!
Also, teflon tape or string or "goo" is only to get you back to the barn in an emergency. Either teflon tape or "goo" is meant to be used only on tapered pipe threads & to be applied only to the MALE threaded portion so none of it is forced inside the pipes. Bill W.
 
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What Bill said! If you have to guck if up, then it's time to start over. Another problem area is over tightening, it will crimp the ferrule too much and cause a leak. Chuck
 
Tinker said:
Kind of depends also where you place the new line when you start tighten also. I find it better to keep the line out a smidge from seat before tighting. Hey or not.
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Yep, you're right, Tinker,
Most ferrule type fittings have a built in stop for the tube. But there is no stop for the tube on a Zenith carb & the line will slide in against the carb screen & restrict the flow. On my '30, the screen was positioned where the tube hit the wide solder joint on the side of the screen & the car would starve out at 20 MPH. Someone else put it in, NOT ME, I'M GOOD! LOL & LOL! It's all Chief's fault, he taught me that I didn't have to act HUMBLE. At least I don't blame my faults on my Mamma like some "groups" do. She was a sweetie! Bill W.
 
Chuck Sea/Tac said:
What Bill said! If you have to guck if up, then it's time to start over. Another problem area is over tightening, it will crimp the ferrule too much and cause a leak. Chuck
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Right, Chuck,
And it's worse on a copper line where over tightening can literally cut the line in two! "FIRE-FIRE":eek::eek: Bill W.
 
Use tube fitting wrench ,there a box wrench a slot at one end ....very common . Open end isn't advisable. Make a trip to craftsmen ......No more fuel leak ......
 
steve s said:
The ferrules should be snug. Maybe they, or the tube, are the wrong size, or maybe you're inserting the tube too far, or maybe the mating surfaces in the sediment bowl and carb are scratched up or otherwise damaged.

I would take the tube and the carb to a good hardware store or local auto parts store and ask someone to show you what you need to do. Hopefully, the same fix will work at the sed. bowl.

Steve
Click to expand...

BILL WILLIAMSON said:
Steve, am I NOT creditable?
I just told him how to do it. I was sqeezin' ferrules afore' lots of folks were BORN!:eek: Bill W.
Click to expand...

Bill,

No disrespect intended; you posted your reply while I was still composing mine, and I neglected to go back and check if mine was obsolete before hitting Submit Reply.


I totally honor your credibility and vast experience at squeezing ferrules, and hope that you will similarly honor my credibility and vast experience at the futility of trying to get mismatched or damaged parts to work until finally getting professional help.


Steve
 
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