Cleaning the gas tank in place?

B

Banditorama

Senior Member
At least it was a nice day for a walk..

Finally got the turn signals done and decided to take the Model A down to the gas station to fill her up. Before I left, I decided to strap my 5 gallon Jerry can to the rear cargo rack to fill that thing up too

I always go to the gas station on the other side of town because they have ethanol free gas and it's a nice drive. I had about a quarter tank before leaving. About a mile and a half from the station, the car starts popping and loses power. I push the clutch in and it dies completely

Pull off into a parking lot, open the hood, and the sediment bowl is 1/3rd full of junk. Real fine silty junk. I dump it and scoop all that out, and turn the petcock on. Nothing flows except a little dark "mud" filled dribble

Unstrap the gas can and walk to the gas station and back. Fill her up and another round of mucky junk comes out, so I dump it and make my way to fill it the rest of the way up. After that, almost nothing showed up in the sediment bowl after I got home. That makes me feel a little better

But, I've got to do something about that tank. I filtered the gas through a bunch of rags when I first bought the car, but obviously that wasn't enough. Any tips, tricks, or tools to accomplish this without pulling the tank out of the car?
 
I have not found a way to clean the tank without removing it. I would suggest removing the tank and having it cleaned and be one with it. Good luck
 
I’m in the same predicament. My 31 Roadster has a beautiful paint job, and I am distraught at the idea of destroying the continuity/quality of the job by taking the tank off the car. Has anybody done any flush similar to polishing fuel in a diesel tank. Any ideas appreciated.
 
Garden fertilizer sprayer filled with a degreaser of choice. The wand can be positioned to spray most parts of the tank from either the filler cap or gas gauge. You can really only apply and soak, and then flush the remaining cleaner out with gas using your sprayer. I have no way of physically scrubbing the inside of the tank.

A restorer in my circle adds fine gravel and shakes the tank to clean, removed from the car. I have no idea how he gets all the gravel back out.
 
BVZ24 said:
Garden fertilizer sprayer filled with a degreaser of choice. The wand can be positioned to spray most parts of the tank from either the filler cap or gas gauge. You can really only apply and soak, and then flush the remaining cleaner out with gas using your sprayer. I have no way of physically scrubbing the inside of the tank.

A restorer in my circle adds fine gravel and shakes the tank to clean, removed from the car. I have no idea how he gets all the gravel back out.
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As a restorer of Model-A gas tanks, I cannot begin to tell you how many tanks we have opened to find all kinds of rocks, fasteners, and debris inside that found its way behind the baffles and never came out again.
 
How do you plan to get behind the baffles to clean ? :confused:
 

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I realize this is done with the tank removed but wondering if anyone has used the etch and sealer available from the dealers? Can anybody tell us how user friendly it was? How has it held up and would you recommend it or use it in your next gas tank refurbishment?
 
I’ll agree that most of the people are correct in removing the tank and having it cleaned properly but I have had some success in adding the cleaner of you choice and putting the car on a trailer and driving it around town especially around turns and then draining and redoing until the majority of crud is removed….
 
Phil Brown said:
How do you plan to get behind the baffles to clean ? :confused:
Click to expand...

Oh my , was that an titanic artifact?
If your motor was smoking, if your rearend was growling, if your transmission howling, what would you do? R&R !
You could try 10-11 gallons of evaporust $$$$
 
Banditorama said:
At least it was a nice day for a walk..

Finally got the turn signals done and decided to take the Model A down to the gas station to fill her up. Before I left, I decided to strap my 5 gallon Jerry can to the rear cargo rack to fill that thing up too

I always go to the gas station on the other side of town because they have ethanol free gas and it's a nice drive. I had about a quarter tank before leaving. About a mile and a half from the station, the car starts popping and loses power. I push the clutch in and it dies completely

Pull off into a parking lot, open the hood, and the sediment bowl is 1/3rd full of junk. Real fine silty junk. I dump it and scoop all that out, and turn the petcock on. Nothing flows except a little dark "mud" filled dribble

Unstrap the gas can and walk to the gas station and back. Fill her up and another round of mucky junk comes out, so I dump it and make my way to fill it the rest of the way up. After that, almost nothing showed up in the sediment bowl after I got home. That makes me feel a little better

But, I've got to do something about that tank. I filtered the gas through a bunch of rags when I first bought the car, but obviously that wasn't enough. Any tips, tricks, or tools to accomplish this without pulling the tank out of the car?
Click to expand...
Install a Dirty Leg as it will catch a lot of the crud and empty often.while you have the gas valve off install a pencil filter in the valve prior to reinstalling
 
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If I had to try to clean the tank while in the car,
I would first mask off everything around the tank top.
Maybe cover most of the front of the car. Empty the tank,
Then remove the shutoff valve and use a barb fitting
to a hose to drain it all when the flushing begins.

Then I would use a light duty pressure washer to remove all
rust and crud that is flaking off. You have to attempt to
attack every wall and bottom that you can. A strong flashlight
& inspection mirror is a must to continually inspect all areas.

Yes, I know, it's water! and water is the tanks worst enemy. But doing just that
for just a few minutes, it won't hurt. Now that all the flaky stuff is mostly gone,
I would use a solution of 99% rubbing alcohol perhaps with a garden pump sprayer
to flush out most of the water. Let dry, fill with gas, add a little MMO, and
that should stop the debris from ruining the gas.

Your strainer should have that newer style paper element in the bowl.
I also use another small paper element filter in line before the carb.

Clean gas is paramount. Now saying all this, It is not a complete
substitute for removing the tank.
 
Try what Dino said above. Flushing with water on an already rusted tank isn't going to be an issue.
 
We had old gasoline deposits, tar, varnish and the like but not so much rust, so we mixed up some LYE - sodium hydroxide with water and being careful not to spill any on the paint job, we filled the tank with about 5 gallons of the mixture. This is the same stuff used to open a clogged drain. It WILL remove paint if left long enough.

https://www.amazon.com/Boyer-Corpor...c-Cleaner/dp/B09LZ7SN9T/?tag=atomicindus08-20

We rocked the car vigorously several times over 2 days to slosh it around thoroughly. It was amazing at how well it cleaned the nasty goo left from old gasoline. After draining and flushing well with water, we did the same process with some phosphoric acid to "pickle" the inside surface of the tank. Drained all the phosphoric and let it air dry for a couple of days.

This process worked well for us to conquer the problems of crud left by old fuel deposits. If your tank has heavy rust, that requires a different approach depending on the severity of the rust.
 
You may want to try some of the gasoline additives that are sold at auto parts stores that advertise removing varnish from the system. Won't do anything for rust but may clean out the brown sludge that forms in the gas tank. Modern gasoline is composed of various molecules, some light weight, some medium weight, and some heavy weight. The heavy molecules form the brown sludge which is related to tar.
 
Gary WA said:
Install a Dirty Leg as it will catch a lot of the crud and empty often.while you have the gas valve off install a pencil filter in the valve prior to reinstalling
Click to expand...


X2 on the "Dirty Leg". I installed a dirty leg on my 1926 Model T's gas tank outlet prior to the sediment bowl. When rust started showing up in the sediment bowl glass, it was time to drain the dirty leg. Worked for me. :)
 
A recommendation if you decide to flush it while it's still on the car is to get another fuel line and cut it before it goes into the sediment bowl. You can also use a barbed nipple attached to the shut off as well.


Attach some cheap hose with a hose clamp to the cut end and have enough length of hose to run it away from the car. This will help with the mess that comes out of tank and preserve the interior of the car.

After it all drains out, get a rubber pressurizing cap at the hardware store and add air to the tank. This will help get all the remaining moisture out of the tank.

Last step, I placed a small battery powered fan over the fuel filler neck and let it sit over night to dry out any remaining product that is in there.

In my case, I used water to test for leaks since my tank was pretty clean inside.
 
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I used a box of small self tapping screws so they could be removed from the tank with a magnet, and they are small enough to go under the baffles
 
As others have said, the baffles will prevent you from getting on the other side of them. Some people have suggested taking the tank off and putting gravel, nuts (steel) or chain behind the baffles and shaking the tank. Paul Shinn on YouTube does it. I can't imagine that it's really effective in removing serious rust. I think the only way to be sure you got the rust out is to have the tank cut open and sand blasted/cleaned/coated and then welded back together. That's what I have had done to my tank. Costs about $1,000.
 
Since your debris is "fine and silty" I think draining the fuel tank, removing the shut off valve and rigging up a drain line from the tank to the outside your A as Dino has suggested is a very good idea.

I wouldn't hesitate to flush the tank with a garden hose multiple times to get as much of the debris out as possible. Shouldn't be a problem having the tank wet with water for a few hours or even a day.

After flushing it out push the car out into the sun, stick an air hose from a aquarium into the tank or even better if you have sleep apnea stick the hose from your c-pap into the tank to bring fresh dry air in and push the moist air out.

After you've got it dried out add a pencil filter into the shut off valve and drive the heck out of it.
 
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