Drippin' gas line inside

Werner

Werner

Well-known member
Guten Abend.

Does anyone have a tip for sealing the stainless steel fuel line running from the fuel shut-off valve to the bulkhead fitting for the glass bowl?
It allways seeps a bit, no matter how tight I screw it down. It smells awfull. It’s the flared connection.

Thanks at all at advance!
 

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Werner - I've had this problem as well. The basic problem is that the sediment bowl casting is pot metal, and once you screw up those threads you're toast. The only solution I was able to come up with (after trying several) was to replace the sediment bowl housing casting with a new one. It's really easy to cross-thread the fuel line into the back of that fitting without realizing it and that will horse up the threads. And to compound the issue, in the past there were some really poor metal repros. If you can find an original in good shape, maybe one of the cast iron ones, go for that.

Once you get the new one, leave the nut that holds it to the firewall loose while you make up the connection from the fuel line to the sediment bowl housing, jiggling it while you do so to make sure it's seated. Then make up the nut to the firewall. You could try that with the one you have, but I suspect that the threads are already messed up.
 
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I had a leak at the other side of the sediment bowl. I wrapped a little Teflon tape around the tubing, being careful not to get any where it would get into the tube to cause problems down stream. The other option is to use some gasoline proof sealant like Permatex Permashield, Part number 85420. The sediment bowl is indeed easy to screw up as Jay Jay said.
 
Werner, I had a leak earlier this year exactly like yours. It turned out the glass sediment bowl wasn't real tight against the firewall, so I first had my son hold the sediment bowl on the engine side with a wrench to keep it from moving while I tightened the big nut under the dash. That got the sediment bowl much tighter than it was before. Then while my son was still holding the engine side sediment bowl with the wrench, I tightened up the gas line under the dash. It was a two man job, but we got everything very tight and didn't strip any threads or even need any thread sealer. Of course, the sediment bowl and gas line were installed new about ten years ago, so all threads were still in good condition.
And for whatever reason, I have been most successful using the old Permatex number 2 instead of Permatex Permashield on gas line threads. Good luck resolving your leak.
Gary
 
Guys- the threads don't seal anything, the seal is the cone on the sediment bulb and the flare on the tubing- that's the surface that you need to seal. As above, a dab of #2 permatex or VERY carefully applied teflon tape to the sealing surfaces. Hope this helps.
 
Werner said:
Guten Abend.

Does anyone have a tip for sealing the stainless steel fuel line running from the fuel shut-off valve to the bulkhead fitting for the glass bowl?
It allways seeps a bit, no matter how tight I screw it down. It smells awfull. It’s the flared connection.

Thanks at all at advance!
Click to expand...

I had the same issue on my '30 Town Sedan. I ensured the fitting was not cross threaded and after tightening (to the point I thought I would strip it), it still weeped.

I finally resorted to a copper flare gasket similar to this https://www.amazon.com/uxcell-Fitti...cessories/dp/B0DP4T3T1F/?tag=atomicindus08-20 and it worked like a charm. No leaks in ~5 years now, 10/21.
 
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You said stainless line, stainless is a hard material compared to something like copper. As you tighten the nut on the flair it should compress and form the tubing flair to the mating flair fitting forming a seal.
I've used stainless on other projects for brake lines and it is a real bear sometimes to be leak free.
I would a softer materal for that line, maybe ni-cop or nickel copper that is now used in a lot of brake lines for new cars. Very easy to work with
 
here is what i would do

first thing, throw all those stainless lines the garbage and start with an original style steel line.
then take off the sediment bowl and make sure the flanges are good and there is no cracks. Never put teflon tape on those fittings, it does no good because the flange is what seals not the treads.
 
I replaced my sediment bowl a few months ago and although I am a former aircraft mechanic and have done this dozens of times, I still cross-threaded the damn thing and had to buy a second one. :(

The copper gaskets are the way to go if everything else is OK. Cracks happen, so use magnification to inspect the tubing flare.
 
Is that a magnet stuck to the tank, next to the shut-off valve?
FWIW, You can fabricate your own "copper gasket" from a piece of 3/8" copper tube, I've done that before.
 
I've seen more than one model A and other Fords with multiple shut off valves. Even My old Ford 850 tractor has problems with shut off since it was replaced with a reproduction valve many years ago. Those early model A set ups had the cast iron sediment bowl that also had a drain valve to dump condense but they could leak too. If all the parts are well made from original type materials then a person can get a good seal but nothing lasts forever. I really like the Voi Shan seals used in aviation. They are a thin copper and many times a one time use item to seal up flares and seats with iregularities in the surfaces. I wished they made them for 45 degree fittings. Aviation uses 37 degree fittings so no help there.

A lot of modern copper flare seals are too thick but some are available that work better, Another caveat is that some cheap Ni-Cop tubing isn't seamless and that makes it impossible to double flare so keep that thought in mind. Materials aren't what they used to be. Ford likely used copper plated steel pipe for there fuel systems. Plain steel works but it may get rusty over time.
 
Guten Abend Ford Freunde!

I decided to go with the copper cone washers that Y. Blockhead showed in post # 6 which other forum members also rated positively too. From a technical standpoint, this makes sense when sofr copper pressed with the two hard mating surfaces behind.

Although I prefore great importance on originality, I made an exception and opted for a custom-made line using thick, 12 mm stainless steel tubing. The fittings are made of high-quality stainless steel, and the pressed cutting-ring system ensures a 100% leak-proof connection. The reason for this is that I used to need the new brass original shut-off valve every 2–3 years because the brass cone would no longer seal reliably. I’ve now installed a brass/PTFE ball valve, and I hope it will last a long time.


Kathy, that’s a 40 kg neodymium magnet. The inside of the tank is rusty, and the magnet keeps some of the rust away from the valve. There is a fine filter with a 15 µm mesh rating in the carburetor supply line, yet some rust dust still glides to get into the carburetor.


I’ll let you know how the copper flares work out once I’ve received them.
 
Werner said:
Guten Abend Ford Freunde!

The reason for this is that I used to need the new brass original shut-off valve every 2–3 years because the brass cone would no longer seal reliably. I’ve now installed a brass/PTFE ball valve, and I hope it will last a long time.
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I had the same issue except I butchered a reproduction fuel line and used a brass ball valve. Ball is stainless with teflon seat.
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Make sure you're not mixing flare angles. A lot of stainless uses the 37 degree angle of the AN-JIC standards not the SAE 45 degree angle.
 

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