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Draining Trouble's Fuel

Laurie S.

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I need to drain the fuel out of my 1968 fastback since it's bad. It's been in the tank since at least 2004, so it's really bad. I have regularly put Stabil in there, but it still has a varnish smell.

I've never done this before, so I would appreciate any advice on what to do. Do I need to flush new gas through the tank or some other fluid after the tank is drained?

No idea how much gas is left, but it's a 22 gallon tank and it was full in 2004, notwithstanding gas fairies.
 
Also, I can't remove the tank due to the metal plate that's bolted over it. It's a brand new NOS tank that we installed around 2002. I do have new fuel lines and a new carburetor installed.
 
No drain plug, eh? I think the thing to do is to remove the sending unit and start siphoning the gas out. Try and get all that you can. At that point, I don't know whether it would be better to simply add new gas or try and flush it with some sort of solvent that you can also siphon out. You're going to have a difficult time getting rid of the solvent, though.

Your other problem is that you have a 22 gallon tank and don't drive Trouble much. You'd be better off with the standard 16 gallon tank installed. Gas tanks last better when they are stored full (or completely empty/dry) and not half-full.
 
Jim Smart set it up with a temporary hose so I can drain the fuel. I'm getting the car ready for our National Show next year and once it is running, I will be driving it. Can't wait actually!
 
Ok...wait....what? Did Laurie say she was going to DRIVE Trouble? Next you'll say the Cubs will win the World Series.
 
Smartass! LOL Just keep those darn gas fairies away while I'm trying to drain the tank.
 
When I pulled my tank I used a siphon that I bought from Harbor Freight Tools to siphon the gasoline in the tank. Much better than the old hose suck method. Be careful though. If there's any significant amount of gas left in the tank you will go for a petroleum swim when you pull the sending unit. Ask me how I know.:( There I was on the shop floor in a gas soaked sweat shirt and a drop light laying next to me. Fumes were coming off the drop light as we laid in the puddle of gasoline together. Fastest I've ever gotten out from under a car. My '69 has a 20 gallon tank with a drain plug. I should have pulled the drain plug, but I thought it would probably leak afterwards and stink up the car.

Why can't you remove the tank? Is the metal plate bolted over the tank on the trunk floor? If so why not remove the plate and then remove the tank?
 
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The plate is bolted all the way around, and I've done a very thorough job of sound and heatproofing the tank, plus carpeting all the way around. I did successfully drain the fuel, and next weekend will put a couple more in and flush it through.
 
my son and I are working on a Bobcat (Pinto) and it sat for 6 years outside with half full tank. We drained it, flushed lines with compressed air and rinsed tank with water, then Heet to remove any moisture. The tank didn't have a drain plug so we drained it via the sender and then actually removed the tank but we probably didn't have to. We thought it would not be savable but it was pretty clean actually. Picture from the filler neck hole before we rinsed it out
gas tank inside.jpg
 
I drained through the sender, too. Should I stick a hose down the filler tube and flush with water?
 
I drained through the sender, too. Should I stick a hose down the filler tube and flush with water?
I only would go that extreme if you can tell there is crud in the tank like we found. Ours had sediment, dirt, rust, whatever it was and I was worried it would clog the fuel filter and carb.
 
Okay, what I drained came out very clean. I'll just flush with more gas this weekend and see if there is any water separation in it this time. Thanks!
 
Laurie have you considered doing your final flush with isopropyl alcohol? Not only will it give a good clean residue free flush, it'll also help with any traces of water which may remain. Just a thought!
 
No, I didn't know about that. That wouldn't hurt the fuel sender? That's what I'm draining out of since there is no drain on the tank.
 
my son and I are working on a Bobcat (Pinto) and it sat for 6 years outside with half full tank. We drained it, flushed lines with compressed air and rinsed tank with water, then Heet to remove any moisture. The tank didn't have a drain plug so we drained it via the sender and then actually removed the tank but we probably didn't have to. We thought it would not be savable but it was pretty clean actually. Picture from the filler neck hole before we rinsed it out
View attachment 27910
Yeah, my tank looked pretty much like that on the inside after maybe 35 years of service, but there was no sediment. Frankly, I was amazed.

Hey, Laurie. What is the purpose of that metal plate in the back of your fastback? Is it intended to be trunk armor?
 
Yes, it's both tank armor and a way to strengthen the rear of the car. The folddown seat is permanently down, so the armor was necessary.
 
Laurie the alcohol flush won't do any damage to the sender. As a matter of fact isopropyl alcohol is a common chemical in cleaning and flushing electrical equipment (such as rinsing away flux after soldering). It leaves no residue.
 
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