Fuel line question

thirt4

Senior Member
I am about to put one of those new "97" carbs on my engine after cleaning out the tank of rust and the line of debris.
The last time I messed with a carb in any fashion, I burned the car to the ground. A sad but true story. Total loss.

I figured that on that one, I must have either forgotten to put a sealant on the connections or somehow forgotten to tighten the carb screws up completely.

On this one, a factory did the carb screw tightening so my concerns are now about my connections.

My question is - Just what is the best thing to use to seal the gas line connections? i.e. compression (tighten to almost breaking), teflon tape (which someone told me is easily eaten away by gasoline) or some type of thread paste?

Thank you.
 
I was told not to use anything on mine, so I didn't and they work fine. Before starting I put a air hose in the gas tank neck covered with a rag, filled the lines until a friend who was watching the engine bay could see fuel in the sediment bowl. No leaks, next cranked it over with no coil wire on. Both 97's were leaking ontop of carbs, too much pressure from the pump. installed regulator began process over with no leaks and fired it up. always kept a extinguisher close. Good luck.
 
No sealant on the fuel fittings. But you must use the correct ford nut and olive fitting, and 1/4" pipe. Napa has the correct fittings. Don't tighten as you describe, use enough force to seal it and don't overdo it.
Have an extinguisher handy and a buddy to look out if you are unsure.
Mart.
 
If the threads are not damaged you don,t need any tape, thats for plumpers.
A float sticking will flood over,always have a air cleaner on in case of back fire.
 
Um, I'd suggest you make friends with somebody who has done this kind of thing before. Watch and learn.

Please:

Do not overtighten compression fittings
Do not use teflon tape
Do not use thread sealants

If the right fittings are used, they will seal themselves with a simple snug fit.
 
Last edited:
The line from the tank should have the ferrules soldered on the line to reduce vacuum leaks. Make sure the fittings are not cross threaded and buy quality fittings from a reliable supplier.
 
I always put a drop of oil on the fuel thread fittings and mating surfaces where the fittings actually seal to prevent galling and make a better seal. Yes, do check the tighness of the factory carb screws to make sure they are snug. Do not over tighten anything.
 
On the lines actual sealing happens at the ball ferrule. Threads serve only to apply the force to compress that and sealer is not needed. If the ball or its seats are damaged or leak for any reason, throwing sealer at the problem is useless.
 
Why not solder the ferrules to the tubing (copper-plated steel, never plain copper) like Ford did originally? All the above advice is worthwhile.
 
I am about to put one of those new "97" carbs on my engine after cleaning out the tank of rust and the line of debris.The last time I messed with a carb in any fashion, I burned the car to the ground. A sad but true story. Total loss.

You scared me into calling in to insure my 36 woodie in my avatar that I will be starting up for the first time after a frame off shortly. I've had it since last February. Not much left of a burned woodie!
 
I never saw soldered ferrules. Solder would prevent the ferrule from compressing. Oil on the threads would be good, not for sealing but to duce the binding or gauling effect of brass to brass you can even hear them squeak some times. G.M.
 
Then you've never seen an original Ford fuel line from the thirties. The solder seals the inside of the ferrule to the tube and the outside of the ferrule seals against the fitting in either the fuel pump or the carburetor depending on which line is involved.

Two of the three flex lines and both pump to carburetor lines shown in the photos employ ferrules. These are NOS parts and in each case the ferrule is soldered to the copper-plated steel tubing.
 

Attachments

  • Book photos 081.jpg
    Book photos 081.jpg
    29.2 KB · Views: 61
  • Book photos 084.jpg
    Book photos 084.jpg
    15.2 KB · Views: 56
When the ferrule is compressed it seals on the seat of the carb and the Ford nut. The tight ID of the ferrule is compressed on the OD of the fuel line as the ferrule is compressed. G.M.
 
I agree with you there,the 2 outside ones look like model "B" style which have a metal tube end on them. ken ct.
 
Ken,

The one on the left is indeed for a '32-'34 four-cylinder and the one on the right is for RHD drive V-8 passenger cars and commercial vehicles starting with the '32 model.
 
The most simple way to check for leaks is to run your finger under any joints. Your finger will show liquid even when you can not see a leak.
 
OK, Why can't you use copper tubing in the gas line?? Been doing that for years, never had a problem. But if this is wrong, I don't need any triouble at my age.
 
Ron, copper has a bad reputation of becoming brittle from heat/cool cycles, and work hardening from vibration. Yes, copper tubing has been widely used for fuel lines due to the ease of bending, and due also to its being assumed to be original on our Fords as manufactured. It was not. Ford used copper plated steel lines manufactured by the Bundy Corporation of Michigan, which continues in the manufacture of this product today.

Given the remote possibility of a copper fuel line rupturing, and knowing of the availability of Bundy tubing as supplied to Henry Ford, the answer to your question is self evident.
 
Back
Top