MTFCA Forum

new gas line do you install 1/4 steel tubing or 5/16
thanks tom

1/4 " - I use annealed steel brake line.

I just get what the vendors have! Seems good 'nuff to me!

Is it a good idea to put an inline non restrictive filter? I installed a new gas tank six months ago.

Sarikatime wrote: ↑

Wed Oct 16, 2024 1:06 pm

Is it a good idea to put an inline non restrictive filter? I installed a new gas tank six months ago.

NO. stay with the stock sediment bowl with its built in screen.
Is there such a thing as a "non restrictive" "filter"?

Tom,
You have two cars listed. I'm not sure but the 1915 might use brass, not steel.

speedytinc wrote: ↑

Wed Oct 16, 2024 1:13 pm

Sarikatime wrote: ↑

Wed Oct 16, 2024 1:06 pm

Is it a good idea to put an inline non restrictive filter? I installed a new gas tank six months ago.

NO. stay with the stock sediment bowl with its built in screen.
Is there such a thing as a "non restrictive" "filter"?

I agree. Any filter is gonna restrict, that's why if you do run one you now need a fuel pump...more things to go wrong. With a new gas tank, good gas, keep StaBil in it during long layovers you won't have any trouble.

If your gas line fittings still have felt packing in them, you may want to dig it out and use the rubber packings from Langs. They work great and are cheap.

RecklessKelly wrote: ↑

Wed Oct 16, 2024 2:50 pm

If your gas line fittings still have felt packing in them, you may want to dig it out and use the rubber packings from Langs. They work great and are cheap.

That's interesting 'cause long ago I tried them and they DIDN'T work! So I went back to the "magic felts" and no problems. Go figure!

So far so good, no more gas smell in the garage. Just hope they last.

I use 1/4" Ni-Copp with the little rubbers but I flare the ends of the line. How nasty is that?

That's the cat' meow, keep the rubber in it's place.

Tadpole wrote: ↑

Wed Oct 16, 2024 3:33 pm

I use 1/4" Ni-Copp with the little rubbers but I flare the ends of the line. How nasty is that?

Interesting.
If you flare the ends of the tubing, they wont fit into the original, stock fittings.
The line extends into the fittings about 3/8" before the felt or rubber seal.
Care to explain what you got going on?

I used Nickel - copper line at first, now I use steel brake line. The Ni-Cu started leaking....when I removed it I found that both ends (sediment bowl & Carb on/off valve) were deformed. I used neoprene packing on both ends.

I put on the fitting and rubber before I flare the line, then when I tighten it everything is squished together for a nice seal. Aviator, it looks like it stretched on you?

I installed it without flaring - simply compressed the neoprene by tightening the fitting. The left pix was the end in the gascolator - it never leaked. The other was in the shut-off, it did leak. I removed the Ni-Cu line after 3300 miles of use so it took awhile to deform.

My Dad worked at a tube mills, and I still have abundant supplies of various sizes of Bundy tubing. I use 5/16" for my fuel lines. Occasionally a packnut has too small a hole for 5/16" tubing so I drill it out.

I make my own sealing rings, from 5/16" neoprene fuel hose. Fuel hose is normally made with an inner layer, a fabric layer for burst strength, and an outer layer. I cut 1/4" pieces of hose, slit and remove the outer layer, and if the whim takes me, the fabric threads. The packnut will squish this inner layer to make a perfect seal.

Hope this helps.
Allan from down under.

I understand the fuel lines were always brass. What puzzles me is did they zinc plate the tubing?

Believe the sweating of added material was done on the seamed made tubing, that was rolled together to make a tube, and sweated the entire length was done to seal the seam.

Here is factory print, note the center comment on finishing the seam tubing. The print in lower right also calls for seamless tubing, under that is the seamed, button be hard to read this print. Print is from the webpage of Benson Ford Center, where one can find a few of the Model T and Model lA parts prints displayed.

Seamed made from brass , dead soft. Seamless from brass tubing annealed.

click on image to enlarge

Bundy tubing is made from thin steel strips rolled through 720 degrees to make a round tube. It is sealed by plating it once formed. It has since been superseded by another form of tube, but it is still more rigid and less prone to expansion under pressure. I do not know if Ford used the same process making the seamed brass fuel lines in the T era. I do suspect that the seamed brass fuel lines were tinned to seal the seam.

Allan from down under.

On mine the seam is quite noticable and it is plated steel.

I’ve used lawnmower in line filters for years. Most are gravity feed systems. I guess you could call them less restrictive but it works.

Bundy tubing came along in the 1930's, so seemed brass tubing is more likely on a T. The original lines I have seen have been plated, probably tinned, and this is likely done to seal the seam.
Some of the stuff my Dad showed me was all pre-bent and flared ready for installation in cars coming down the assembly line. Brake lines, fuel lines, even hydroelectric suspension lines were pre-formed, ready to hook up at whatever workstation they came to.

Allan from down under.

The gas line being sold by dealers is steel and 5/16th in diameter with no seam and comes with the bend photo above.

More important is for it to come forward and go in front of the exhaust pipe at about the angle in the paper above.

Then 2 or 3 inches has to be cut off after the line is in the sweet potato.

Gas lines sold by at least Lang's are avail in both steel (item #2909) and brass (item # 2909BR. ...for about 4x the price of steel) , all are 1/4" dia. tubing., 43" straight length. Bending the gentle curves by hand is easy with steel tubing.

Like to use the later '24 Ford instruction on lacing the line, that is simple as the line goes not under the wood block, but between the frame and hogshead direct to the carb.

The bend under the gas tank should be so there is about 2" clearance for eliminating issues of heat transfer.

As for the diameter, using anything larger than 1/4" tubing gains nothing.......the line goes to the carb, the carb float needle seat controls the volume of flow, not the fuel line size. If you want the best performance, use Scott Conger's Full Flow Needle and Seat, that is the correct Ford size, all the other repro seat diameters are smaller than factory.

Full Flow

Slightly off topic but, I don't have a gasket on my gas cap. My garage smells of gas and my gas line doesn't show signs of leaking. Could not having a gas cap gasket do this?

With my experience with our vendors, fuel lines do not come pre-bent ..... They do include instructions. Here's a copy from one of the vendors.

Lack of a cap seal will allow fumes to escape. My garage smelled like gas until I used yellow LP gas sealing tape on the strainer bulb and carb elbow thread fittings. Ive used it it a bunch of times and I dont think there is anything else out there that will withstand gas. Also replacing the felt seals on the gas line with rubber helped. I have a new gas cap gasket but recently drillled a vent hole in the cap. It didnt have a hole. I dont think the hole emits that much fumes. I usually run the car out of gas and then push it into my garage.

I can't believe that the vendors sell an unvented cap. Using a gasket on same will cause real problems of fuel starvation, because air will not get into the tank to allow fuel to continue to flow. The answer could be as simple as leaving the cap loose on the thread so air can enter the tank.

We find brass Ford logo caps here in Australia. They are usually unvented, because they are radiator caps for English ford Prefect/Anglia cars. With a small hole for a vent, thwey make ideal T fuel tank caps.

Allan from down under.

Mine looks a recent new repro but it didnt have a hole. When I stopped for gas and opened the cap there was alot of suction.

Well, I was wrong again!

The size depends on whether it is a tubing or a pipe!

My measurement was 1/4th for the outside diameter or 5/16th for the inside diameter.

The gas line will fit in the 1/4th hole, but will not slide through it with my General gauge.

The inside matches the 5/16th hole.

J1MGOLDEN wrote: ↑

Mon Oct 21, 2024 9:07 am

My measurement was 1/4th for the outside diameter or 5/16th for the inside diameter.

Huh?