Draining and Flushing Fuel Safely

[Bernica]

OK, my car has been sitting for over a year with about 1/4 tank (42 gal tank) of old fuel. Getting time to bring things back to life and thinking I want to drain the tank, flush things out and bring some new fuel home to get things started right.

Prior to parking it, I had just changed out all critical fuel lines to good stuff.

I don't have a fuel cell. It's an aluminum 42 gal tank with no drain plug.

My first impression is that I will have to cut loose the fuel line up near the carb and just run the electric fuel pump(s) until it pumps dry. I have done this before, but it scared the hell out of me since I was in an enclosed area.

Past experiences doing things like this would keep me up at night, so I thought I would ask for any tips out there.

Thanks in advance!

[talos]

Disconnect the line at the carb. Run the old fuel if the pump works into a container, until the pump runs dry, and the tank is empty. Add 5 gallons of non ethanol fuel into the empty tank. Repeat the process. Empty this fuel into a container. After everything is dry again, install a good fuel filter as close to the fuel tank as possible. Rebuild or disassemble the carb for flushing. Refill the tank with good non ethanol fuel. Re hook the fuel line to the carb. Start the pump and check for any leaks. (During this process work in a well ventilated area, clear of open electrical wiring, and a fire extinguisher near by). Sounds like a lot to do, but its not. Take your time, respect everything, and don't be nervous.

Tom

[Bernica]

Thanks Talos.
Good advice. I worry about pounding my nice SW fuel pumps to do all the work though. Thought about snaking a hose down the fuel inlet and coming up with some kind of suction device to drain the tank right into a container, similar to the oil extraction devices folks use to service their cars. A well ventilated area and plenty of fire extinquishers however I do it for sure!

[patrickt]

If you put your nose right over the open gas filler tube and sniff, what does it smell like? (this is not a joke)

[Bernica]

Originally Posted by patrickt

If you put your nose right over the open gas filler tube and sniff, what does it smell like? (this is not a joke)

Sort of smells like gas, but not like gas I know or used to know. Almost like vinegar if that makes sense.

[patrickt]

Originally Posted by Bernica

Sort of smells like gas, but not like gas I know or used to know. Almost like vinegar if that makes sense.

That makes perfect sense. It is bad - you must replace it. When you do, you might be surprised that it actually has changed color as well.

[Bernica]

Originally Posted by patrickt

That makes perfect sense. It is bad - you must replace it. When you do, you might be surprised that it actually has changed color as well.

Patrick,
Yup, I learned that and posted about it a few years ago. There is a pic in my gallery about it. Gas goes bad faster these days. Here's the link.

Old 101 vs New 101 - Club Cobra Photo Gallery

[lippy]

What about siphoning most of it out, and topping up with fresh gas so you dilute most of the older stuff? Drain the carb too. I doubt the amount left in the lines would hurt things.

[joyridin']

I assume your pick-up is at the bottom of the tank, so here is what I do. If you have a vent, plug it. Unhook the fuel line and put it in a bucket/gas can. Take a rag and wrap it around an air gun. Just put it against the gas filler tube and pressurize the tank a bit. It does not take much pressure, but a 42 gallon tank will take a fair amount of air. I drained about 10 gallons out of my tank in about 10 minutes and I did not have to worry about pumps or anything electric.

BTW..my gas was about 4 years old. I trickled it in with new gas in the daily driver. No problems at all.

[patrickt]

If it was me, I'd just use a plastic tube and a five gallon can to syphon it dry. Pour the varnish/gas out in to a field somewhere. I'd just make a couple of trips, and I would not put a lot of effort in to this -- if you get the gas level down to where a plastic tube doesn't syphon any more gas out of the tank then you'll be fine with a full tank of fresh gas.

[razerwire]

I had to drain tank one time and unhooked fuel line at fuel filter which is about two feet from tank and put on off valve on line so i could stop flow when i needed to change containers to hold old gas. i use a line with outboard motor squeeze bulb to siphoning gas most of time, but could not use on cobra because neck has flapper valve to stop spills in case of roll over. i checked with distributor to see if any unleaded race gas was free of ethanol but none is. was told by Trick Racing rep that it does have two year shelf life.

[Bernica]

This is all great info! Not just for me, but I posted so that others can learn and be safe as well. Thanks to all of you.

I do like the idea of pressurizing the tank a bit and blowing it all out.

Old School siphoning is going to be first. I think I remember how to do that from back in the gas rationing days. Not saying I would have ever done that, but heard about it.

[patrickt]

Originally Posted by Bernica

Old School siphoning is going to be first. I think I remember how to do that from back in the gas rationing days. Not saying I would have ever done that, but heard about it.

You know, if you jack one corner of the car up you can get the gas to all go in to the opposite corner of the tank. Just make sure your syphon tube is long enough to get in to that corner and have the other end below the level of the tank. Suck on the tube until you get gas up to your mouth, put your thumb on the end of the tube, and put the tube in to your can that is below the tank level. Take your thumb off the tube and gravity will do the rest. And if you taste a little gas it won't kill you.

[Bernica]

Originally Posted by patrickt

You know, if you jack one corner of the car up you can get the gas to all go in to the opposite corner of the tank. Just make sure your syphon tube is long enough to get in to that corner and have the other end below the level of the tank. Suck on the tube until you get gas up to your mouth, put your thumb on the end of the tube, and put the tube in to your can that is below the tank level. Take your thumb off the tube and gravity will do the rest. And if you taste a little gas it won't kill you.

Yeah, I know the drill. I was somewhat kidding before. I have puked plenty of gas! But, still good to post for some that haven't. Like you said, the second you taste it, spit and plug the hose. Then put hose into an appropriate container. It all works with gravity and your appropriate receiving end has to be lower than the giving end!

[patrickt]

99% of high school boys today could not identify a carburetor on a car's engine, 98% couldn't tell you how to safely jump start a car, and 97% couldn't syphon a gallon of gas out in to a can.

[Bernica]

A Yup. I have a son that is a senior in college that meets all of that criteria.

[mdross1]

If it were mine I would top it off with fuel and run it. I have tractors that sit for years with same fuel they start and run instantly. Our Cobra sits a lot we never drain fuel because I know it will burn. In all these years have never had an issue with bad fuel other than the ethanol being hard on soft parts especially in very small engines.
I do use the Fitch fuel catalysts in all our vehicles including tractors

[Mark IV]

Originally Posted by patrickt

Pour the varnish/gas out in to a field somewhere.

Oh the EPA must just LOVE you!

[joyridin']

Originally Posted by patrickt

99% of high school boys today could not identify a carburetor on a car's engine, 98% couldn't tell you how to safely jump start a car, and 97% couldn't syphon a gallon of gas out in to a can.

Kind of like this?

[bobcowan]

Originally Posted by Bernica

Thanks Talos.
Good advice. I worry about pounding my nice SW fuel pumps to do all the work though.

Not a problem. That's what they're designed to do. They run all the time when you're driving. Just disconnect the line at a convenient spot, and connect a longer line that will lead into a fuel jug.

Then ground out the fuel pump relay using a dead-man type of arrangement. 20 gallons of fuel is a lot, so you'll need plenty of fuel jugs.

If you're worried about fumes, open the garage door and turn a fan on. The fumes are heavier than air, and will flow like water.