I make it a practice to shut off the fuel below the gas tank and at the carburetor.
Is this overkill, or is the carburetor petcock sufficient?
Well, so far (4 years) I've gotten away with just shutting it off at the carb, then draining the carb bowl every time I put the car away.
I shut the gas tank sediment bowl valve once every month or so, when I disassemble the carb petcock for cleaning and lubrication with EZ lube (aviation fuel lube).
Also, once a month or so, I drain a cup or so of gas out of the bottom of the gas tank sediment bowl and let it sit in a jar so that I can see if there is any sediment or water in the gas. If it checks clean, I pour it back into the tank through a paint filter.
The original petcock was placed by Ford under the gas tank. Many people add one at the carburetor to avoid crawling under the car every time they park. If both valves are in working order, it is not necessary to close both of them when you park. You can leave the one under the tank open all the time unless you are going to remove the carburetor. Then if the one at the carburetor is in or near the elbow, you will need to shut the one under the tank.
Either one by itself is probably enough, but you're not hurting anything.
I dislike a carburetor shutoff because of:
1 its appearance, especially a ball valve;
2 if not a ball valve, it's so stiff I need a wrench to turn it.
Instead of a carb shutoff I use a handle under the running board that controls the sediment bulb valve. I can shut the gas off without having to crawl under the car.
I have two valves, I shut them both off at the end of a day. But if I just say drive it to work, then only the carb one gets shut off.
As mentioned, one is probably sufficient, but I personally feel better with two. I use brass shut offs, not ball valves. They do need attention every so often as Mark points out. That depends alot on your use. EZ Turn lube is what I also use. A tube will probably last a lifetime.
Yeah, I do the same thing. -My house has an attached garage and my Flivver sits eight feet below my bed, so I'm a little bit paranoid when it comes to gasoline. -When the car is indoors, I put both fuel valves in the off position.
I have a battery disconnect switch, too.
Many thanks for the input...
I always turn both the in line valve off before the carb and at the fuel bulb on our 27. The 26 at the bulb. I haven't added the other cut off. I also drain the bowl when I park them.
Model T gas tanks are open system, so any fumes coming out the cap will sit on the ground and can still go boom! Even if you run the car till it quits there is still gas in the carb bowl.