Feed Pipe Pack Nut`

[Original Smith]

I recall the original feed pipe pack nuts have the felt packing in them. From what I remember, they seemed to have been soaked in a sticky substance.
What is it that Ford put on those felts?

[Ken Buhler]

Hello Larry,
Is it possible that it is wax? I have taken many apart but never tried the melt test.
Ken Buhler

[Rich P. Bingham]

FWIW - I’ve always used the felt packing on the carburetor feed pipe. Once disturbed, they seldom seal well on reassembly. Felt “donuts” from the vendors come dry, the old packing can be difficult to remove from the pack nuts.
New, dry felt doesn’t really want to go in the nut and around the pipe. I’ve found the felts currently available work best cut in half and then soaked in oil. The mention of wax leads me to consider soaking the felts in melted paraffin.

[DanTreace]

Prefer to use modern neoprene fuel line, compresses great and lasts.

Ford didn't mention in Service book of any wax or stuff on the gas line felt, can't find any part number for such sealant.


As to any wax or sealant if you use felt, would be more worried of bits of such added stuff working its way to the carb float needle

[Original Smith]

There are some good replies here. I'm going to try the neoprene packing. The felt has given me nothing but trouble, and I believe after many tightenings with new felts, they have caused the brass fuel line to dish in slightly, so I'm also thinking about replacing the brass line with brake line tubing.

[TRDxB2]

Its hard to tell what might have been used by someone when taking apart an old gas line. I doubt that Henry would have used anything that added cost to what he may have had on hand.

Old oil & petroleum jelly will coagulate, meaning it will thicken and may solidify, especially when exposed to low temperatures, due to the natural process of waxes within the oil crystallizing and clumping together.
Recently I plucked out a felt from an old pack nut and unable to tell if its felt (for sure not neoprene) - need to get the magnifying glass out will add a picture later

[AndyClary]

Any chance that some initial fuel seepage may have turned to varnish over the years?


Andy

[Allan]

I make my own packing like the blue neoprene ones pictured. I cut a short bit of 5/16" fuel hose, slit the outer layer and remove it, and just use the inner layer as the packing. They can safely be reinstalled most times.

Allan from down under.

[Rich P. Bingham]

. . . I plucked out a felt from an old pack nut and unable to tell if its felt . . .

The “go to” common fix back in the day was a few wraps of common cotton packing string and brown soap.

(not common anymore. When was the last time you bought an item in a store, and they rapped it in brown paper and tied the package up with string from a big spool of it on the sales counter ?)

[TRDxB2]

Its hard to tell what might have been used by someone when taking apart an old gas line. I doubt that Henry would have used anything that added cost to what he may have had on hand.

Old oil & petroleum jelly will coagulate, meaning it will thicken and may solidify, especially when exposed to low temperatures, due to the natural process of waxes within the oil crystallizing and clumping together.
Recently I plucked out a felt from an old pack nut and unable to tell if its felt (for sure not neoprene) - need to get the magnifying glass out will add a picture later

The pack nut, felt, is hard as a rock, feels dry and not sticky but still a bit fuzzy on the outside. So?

[Dan Hatch]

Would not Fuel Lube work there?

[Henry K. Lee]

A very simple solution in keeping it “original” and not leaking, use only 2/3 of the felt packing, get a 6mm spring washer from a hardware store that will fit inside of the packing nut and put towards the nut side. Lubricate with Gulf Wax such as used in canning on the threads and fuel pipe by rubbing hard to melt onto. The biggest problem is without the washer, the felt wads up and does not compress properly. Never had a leak in 35 plus years and have done many.

Just Sayin’

[Original Smith]

I just received some neoprene packing from Lang's. I will see!

[Henry K. Lee]

But it is not “original” to Henry Ford’s specs….., how can it be better? Does it match modern valves and brass thrust washers in the rear end as well? The car has no real value now.

[Original Smith]

I remember in the early 1960's, original steel fuel line packing nuts were available. At the time, I was only 17 and didn't know what was in the nuts, but as I recall, it was a packing material that may have been soaked with something. I used to dig them out, and replace it with a a brass ferrule to seal the line. I had a 1926 at the time, and NOS fuel lines were easy to come by then too.

[Allan]

The brass ferule used around the pipe in a compression fitting is an accurately machined piece with a taper on EACH side. The nuts and receivers used in conjunction with these have similar machined tapers on the inside. When the two are mated they result in the ferule being crimped onto the line to make the seal. This setting of the ferule allows the joint to be undone and re-fitted multiple times.

A model T packnut has a machined hole for the fuel line, a machined thread to fit it, but will have no taper at the base because that surface needs to be flat to compress the felt seal used. Being machined, it may be consistent enough to crush the taper on a ferule, but it is not an ideal fit. The corresponding carburetor elbow and fuel tank bowl outlet are not machined. They are as cast. They will not provide consistent contact with the other side of any ferule, so will not give an even crush on the ferule taper on that side. So, at best, there may be a compromised seal on one side of the ferule. Good luck with relying on that to be fuel proof.

Allan from down under.