Fuel System Overhaul

[mbowen]

When I purchased my ‘24 touring early this month I knew most of the fuel system plumbing was better suited for feeding water to a toilet than gasoline to a carburetor, but it wasn’t leaking at the time so I mentally put it on the take-care-of-it-later list. However, after being gone for a week back around the middle of the month, I came home to a strong fuel smell in the hangar where I keep both T’s. Bonnie (‘24 touring) was down 5 gallons. Even though the fuel valve was off there was a slow drip coming from the carburetor area, which turned out to be a loose fitting connecting the fuel line to the inlet elbow. There was also some dampness around the tank outlet, so to be on the safe side I drained the remaining fuel in the tank.

I have a new sediment bowl (brass potato), drain petcock, steel fuel line, fittings, seals, and shutoff valve on hand, but I’m going to take care of the tank first. Except for some surface rust on the interior of the tank, what I can see on the filler side of the baffle looks pretty good. I just need to clean up what ever was used to seal around the outlet and come up with a plan to repair the leak(s).

[MichaelPawelek]

Looks good!

[mbowen]

As I mentioned in my original post:

…I have a new sediment bowl (brass potato), drain petcock, steel fuel line, fittings, seals, and shutoff valve on hand, but I’m going to take care of the tank first.
…

[speedytinc]

A bit OT. As a rebuilt carb provider, I have been forever frustrated with them coming back with the drips. My policy is to show they are leak & stick proof before the sale via multiple "suck & blow " tests. Plus an explanation of cleaning the grit out if a drip develops. Viaton needles.

Even got myself. Customer car. Supposed cleaned, coated tank, new sediment bowl. I replaced the coper compression line with steel & no excess fittings. Left the carb gas valve on over night. Puddle in the mourning. Took it apart & found fine grit on the needle. How, Why, ARRG.!
Cleaned it. Been dry a week with the gas left on as it should be able to do. I have carb shutoff valves on all my T's, but rarely use them. Never had an issue. The moral is: Have & use a carb gas shutoff & a clean fuel system aint always clean enough.

[TXGOAT2]

Not all pump gas is clean, and most gas cans aren't clean. Funnels seem to attract and hold everything. I think Model Ts are especially hard on needle/seats due to engine vibration, and general vibration throughout the car tends to keep any trash in the fuel system, including in filter bowls, in suspension. It also tends to reduce larger bits of debris to smaller bits, which can travel more easily through the system.

[mbowen]

There is some surface rust inside the tank, and the gas in sediment bowl felt gritty. I don’t think my leak was the carburetor, just a loose fitting at the elbow, so evidently that sediment bowl was doing its job. Most airplanes have sediment bowls (gascolators) near the low point in the fuel system which we drain a few ounces out of every day we fly to remove any accumulated grit and/or water. That might be a good habit to get into on the Model T.

I’ve read of success with POR15 in cleaning and sealing the tank. I had never heard of that product before getting into model T’s so I want to do more research before I use it.

(BTW, does anyone recognize what the sediment bowl in the top photo in my original post might be from, or is just something generic?)

[Jerry VanOoteghem]

Miles,

If your existing sediment bowl is glass, I would be afraid of a stone hit taking it out some day.

[mbowen]

Miles,

If your existing sediment bowl is glass, I would be afraid of a stone hit taking it out some day.

I never had any intention of reusing the glass sediment bowl on either of my T’s. I got a new brass “potato” sediment bowl from Snyder’s before I even took the current system apart. I was just wondering what the one that came on my touring car might have come from. I’ve seen similar ones on old tractors.

[Oldav8tor]

I had a sediment bowl like that on my 1953 Ford NAA tractor and one similar on my 1946 Aeronca Champion aircraft.

I treated my tank with the POR 15 kit with great results. It was in worse shape than yours crud-wise.

I suggest you replace your copper fuel lines with steel - I used brake line that I cut the flares off. My copper lines deformed where they went into the sediment bulb and carburetor fuel valve.

[mbowen]

…I suggest you replace your copper fuel lines with steel…

…I have a new sediment bowl (brass potato), drain petcock, steel fuel line, fittings, seals, and shutoff valve on hand, but I’m going to take care of the tank first…

[Oldav8tor]

Oops! I always told my students to be sure to read everything.......guilty!

[mbowen]

I finished sealing the tank with POR-15 two days ago, and I’m quite pleased with the outcome (so far). The sealant was hard to the touch within 4-5 hours, but the instructions say to wait 96 hours before adding fuel. I’m confident enough that the tank won’t leak that I’m going to go ahead and reinstall it in the car along with all the new components and plumbing.

Right (Filler) Bay

Center (Outlet) Bay

Left Bay

[DHort]

I use copper fuel line. It is easier to bend in to place and has worked fine for years. I have no leaks & no issues.

However there are two caveats:

1. No flaring on the ends. The pipe is cut straight and felt or neoprene are used in the fittings.
2. My tubing is thick walled tubing. Not the thin stuff you buy at the hardware store for your refrigerator. I get mine from my mechanic. Perhaps he gets it from Grainger or McMaster.

[Oldav8tor]

The tank came out great! You'll be very happy with it.

I initially used copper/nickel brake line to make my fuel line. I started seeing some fuel weeping around the attachment point to the carburetor and when I investigated, found the ends where they attached to the fuel valve and sediment bowl had been deformed (see pix.) I switched to steel brake line and haven't had any problems. Note: When you use brake line, cut the flares off the ends and use the neoprene gasket.

sediment bowl on the left, fuel valve on the right

[mbowen]

Thank you Tim. While I was ordering all the other fuel system parts from Snyder’s I had them include a steel fuel line; I figured I couldn’t go wrong at $4.75. Everything between the tank and carburetor will be new.