delta254

Whats the best way to clean the fuel tank, i have put in about 5 gallons of gas and theres no gas getting to the fuel filter or carb, so we hooked it up with a portable gas tank fired right up so i know its not the fuel pump, and the carb just got rebuilt, it must be from the tank to the fuel pump please help thanks guys.

MDchanic

You've got to start at the fuel pump and work backward.

First thing to check are the rubber hoses, from the tank to the steel lines, and from the steel lines to the pump. If the hoses are cracked and let air in, the pump will suck the air instead of sucking gas. If the hoses are good, look at the lines. If the lines don't have any obvious rot, then use a compressor to blow through from front to back - if there's some crap in there, you'll probably blow it out. If none of that works, then you've got to drop the tank (you'll be happier if you get the gas out first) and pull out the sender and pickup. The pickup sock may be full of gunk, but it's less likely than the other things, in my experience.

- Eric

delta254

well try that forst before we drom the tank... about how much gas should should we put in(gallons) in order for the fuel pump to pick it up so we can test it?

MDchanic

Hard to say - a gallon should be okay, two for sure, so long as the car is level.
Whatever you put in, you'll have to take out before you drop the tank - each gallon weighs about 6 pounds, so the less in there, the easier the job is.

- Eric

delta254

thank you were probly gonna drop it anywayz and blow all the lines and replace any if needed, whats a good way to clean it maybe high pressure at car wash?

roamer

A friend of mine had the same problem when he rebuilt a 69 n
Nova. A spider had built a nest in the first corner of the fuel line after the gas tank. Plugged it solid. If your car has been sitting for years with no gas in it you find a critter remains in the line. Start at the gas tank and move your way forward. Depending on your budget you may want to replace the gas line now and eliminate future problems on the open road.

MDchanic

I really don't have any specific advice for you there.

I'd keep it simple and just blow it through with air. You could pump a bit of gas through after that, and I'd run a pretty big fuel filter for the first few months, just to be sure I caught anything that came through.

As for the tank, the standard (if it's really bad and needs cleaning) seems to be water with a strong detergent, followed by a strong solvent like MEK (methyl-ethyl ketone) if someone before you coated the inside (those coatings are hard to get off), followed by a strong phosphoric or hydrochloric acid solution and some sort of abrasive (lengths of chain, nuts and bolts) to loosen rust and scale, followed by a rinse, dry, and recoating. Usually, though, the tank is either pretty good or has holes in it, so you're either giving it a slosh and running a filter or you're replacing it.

- Eric

Allan R

NOOOO!! You take a gas tank to the car wash to clean out and you'll have the EPA breathing down your neck and hopefully you won't blow the place up. Unused fuel and gunk at the bottom of the tank can get into the car wash drainage systems and may not get filtered before being released to the environment. If you need your tank cleaned, have it done professionally. Industry is regulated by TDG and EPA for hazardous materials. All you want is a clean tank back.

MDchanic

So does that mean we're not supposed to change our oil by pulling up over a storm sewer and unscrewing the drain plug? I was always afraid the drain plug might fall into the sewer...

- Eric

jaunty75

I removed and cleaned the tank on my '67 Delta 88. The car had 130,000 miles on it. I found the inside of the tank to be much cleaner than I was expecting. Remember, gasoline is a solvent, so it will generally keep clean anything that might deposit on the tank walls and bottom as long as gas is being run through it relatively regularly.

If the car has been sitting for some time, then, yes, some deposits might have occurred. But even in my case, where I know that the car had no more than about 4,000 miles put on it between 1985 and 2009, which means barely more than 150 miles per year for 24 years, the tank was still free of any deposits.

What WAS in the tank was loose sludge. But the point is that it was loose. Once I removed the fuel pickup line/fuel gauge sending unit, the opening was big enough for me to get my arm in there. With a good rag, I was able to scoop up all the sludge. Of course, you tilt the tank around a bit to get the sludge as much under the opening as possible.

Then I just poured some gasoline into the tank (half a gallon), swished it around, and dumped it into a bucket through the filler neck. A couple of times doing this, and the tank was pretty darn clean. I then burned that wash gasoline in my lawn mower.

There was nothing about my car's tank that would have been cleanable with a high pressure stream of water. I doubt there would be in yours, either. But take it down and take a look. Whatever you end up doing, you'll be glad you did because you'll know with certainty the condition of the tank. When I did my tank in 2009, I was pleased to see that, even though it was then 42 years old, it was in very good shape, with no dents and just the barest of surface rust. I cleaned it up both internally and externally and then repainted it before putting it back on the car. Not that anyone sees it under there, but *I* know it's painted!

delta254

Got the tank off.. tank looks fine inside and out no rust. Rubber lines are toast Im sure that was the problem, my sendeing unit looks good as well i just need to put a strainer on it the one on is tore. I hope to find it with buying the whole sending unit. As far as the tank were going to run some thinner through it and call it a day.. thanks guys

MDchanic

All's well that ends well...

- Eric

jaunty75

You know, if it were me and I could scrape the funds together at all, I would go ahead and replace the sending unit since you've got the tank out of the car, anyway. No matter how good it looks, the original one is now 37 years old. They don't last forever, and the only thing more annoying than having to remove the fuel tank once is having to remove it twice.

Just my 2 cents.

delta254

good call thank you

jaunty75

Plus, the new sending unit will come with a new sock filter, something you'd have had to pay for and replace on your current unit, anyway.

delta254

Just needed rubber hoses starts right up know.