Fuel shutoff valve

MrTube

Well-known member
Getting ready to change out the shutoff valve and am wondering if there is anything I should be aware of before I try to unscrew a valve from an 80 year old gas tank ;)

Do these usually come out easily or is it a nitemare?



Thanks,

Chris J.
 
They can be tricky especially if there was any old fuel it it before. I usually get a good grip on it and wiggle it back and forth to break the threads free. Oh and pull the floor boards and the kick panels if you have them, and keep a bucket ready to catch any fuel remaining in the tank. Make sure there are no sources of ignition available to ruin your day.
 
"good grip"? please explain?

I am about to remove mine as well, and there is no way it is coming out by hand. And I really don't see a nice way to grab onto it mechanically either.


Since I am replacing ours I was thinking a large pair of vice grips. Maybe there is a better less destructive way though?
 
Keep the drop cord and light bulb out of the way. The gas drops on the bulb and breaks the bulb and you have a fire. I just used a big wrench on mine. If the tank is in bad shape the whole bottom may twist out. I think vice grips might work.
 
I just did this. Use a good wrench, one as long as you have - let's you apply more pressure and, more importantly, better control how much pressure is being applied. I would use vice grips only as a last resort as they tend to grind off the flats on the valve, thus reducing your ability to get a good purchase on it. If you don't have a wrench that will fit, I'd suggest buying one - that and patience may make the difference between success and real trouble.

It also helps to tap on the valve body using a small hammer and a drift pin - tends to break loose any corrosion that may have built up in the threads.

I had to apply a lot of pressure to move the valve in my tank - more than I'd like but it turned out okay! Once you get it moving a bit, alternately loosen/tighten until the threads seem to be freeing up.

I had a shallow plastic container handy to catch the inevitable outflow of gas left in the tank. Disconnect the battery and make sure that there's no way to drop a wrench across the terminals or neg terminal to ground, generating a spark!
 
Should I use anything on the threads of the new valve or just screw it into the tank?

I have the screen that goes on the tank end so i'm covered as far as that.
 
I used Permatex "form-a-gasket" in the little tube,It's gasoline proof, no leaks on mine yet after 2 years. The tall micro-filter that fits into the intake port of the valve works well too. I also secured it to the valve with a tiny bit of the Permatex.
 
I used a 12" adjustable wrench and protected the fitting and threads by using leather. I put one hand on the head of the wrench and used my other hand to push on the wrench handle, so it's pushing with one hand while pulling with the other. You want ot make all the force a turning force on the fitting, and not a sideways force, wihich may snap the valve, leaving threads in the tank.
 
I put the electric fuel cut off i got at MIKES it works GREAT , when you turn the car of the fuel is cut of. No more wondering did i turn the fuel off . try it you will love it . GOD BLESS
 
I drained mine through the line to the carb and got 99+% out of the tank. Big cresent wrench and a small bucket underneath. Permatex on the new one. No problems.
 
Be sure you have purchased a good quality new valve. I purchased one and after putting it in, when I turn it off it leaks and refills the carb. You may be able to test it by trying to blow through it when it is off-not sure if that works but it may. I am about to go to the electric valve Jerry mentioned.
 
You didn't mention year of car that you will be doing this on. If it's a late 31 indented firewall it's easier as the connection is in the engine compartment. In the cab makes it more difficult but just take your time. Look at the threads, do they look rusted or corroded?

When I changed mine I drained as much as I could out of the tank and then jacked it up on the right side so the remaining fuel would run to the opposite side of the tank. Worked like a charm.
 
I drained mine through the line to the carb. Got about 1/2 cup or so when I loosened the valve. TinCup's idea sounds like a winner!
 
I have had done it many times by taking a drift pin punch that is JUST a bit smaller than the gas line hole, insert it ALL the way in, then use the hole end of a cresent wrench to apply the pressure to it...
 
If you have a fitting that is the same as the fuel line just put it on the vale and snug it up. You can then take a wrench or adjustable wrench and put it over the end of the fitting and you'll have enough room the get it started. Once it moves you can use a box end wrench to turn it more. My 2¢
 
On the late 31's with the indented firewall, a crow's foot wrench is just the ticket for getting it loose.
 
I recently have changed one and also added a filter/strainer that attaches to the new valve and goes into the gas tank.
 
I agree with mass-a-man use #2 permatex. When you start unscrewing it turn it back in and out until you feel it will come out easily. Hope this helps.
 
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