Fuel tank pickup mod/rebuild

In the course of cleaning and repairing my fuel tank, I installed a new sender and then discovered that the original fuel pickup tube had a small pinhole rusted through the curved part as it came out of the tank. Being a bit skeptical of its integrity further down into the tank I decided to dig in deeper. Here's what I found:

First, the pickup tube is soldered into a bung which is riveted the soldered to the tank top. I melted away the solder, then drilled the rivets off to get it loose:

http://img165.imageshack.us/img165/3...okenloove2.jpg

To get it out of the tank, I had to drop it in, then fish it out of the filler hole because the bung is installed from the inside. Once out you can see its design and the rust hole in it:

http://img165.imageshack.us/img165/6...edamagecj5.jpg

Here is what it looked like when I tried to pull the sock off the tube (!) :

http://img292.imageshack.us/img292/6...andtubeyj1.jpg

The only part I salvaged was the actual bung for the tank:

http://img292.imageshack.us/img292/5...fittingia6.jpg

Next, I drilled and tapped it to fit a 90 degree 3/8" fitting:

http://img292.imageshack.us/img292/7...lbownewnr3.jpg

With the fitting on top, I brazed in a length of 3/8" steel line. Note: this is very important to braze this, as you need to solder the bung back into the tank and solder here will melt if you use it to secure the steel pickup tube:

http://img165.imageshack.us/img165/7...kpickupwp3.jpg

Then, using some fine brass screen, I had to make a sock for the pickup. I used this, because you only have a small hole to fit through when reinstalling the pickup. I chose to install it from the outside to make things easier:

http://img292.imageshack.us/img292/1...anksockws7.jpg

More in the next post.....

Once the pickup was finished, I cleaned the tank top surface very well and using flux and a wire brush prepped it to solder the new pickup back in place:

http://img292.imageshack.us/img292/9...epickupou7.jpg

Here is the new pickup soldered in place:

http://img292.imageshack.us/img292/5...olderedcs2.jpg

And lastly all painted OD:

http://img165.imageshack.us/img165/6...stankodks7.jpg

This pickup most certainly would have left me sitting eventually even if it had not had the hole on top. I also used 3/8" line all the way which may be a help for the V8 swap too. The original line was 5/16". If ever there is a need to get in there again, the pickup can now be removed from the top instead of from the inside as it was originally.

Absolutely outstanding!!!!!!!!!!!!!!!!!!!!!!!!!!!!

Thanks so much for all the pics and detail!!!!!!

Fantastic post, man! Thanks!

...Makes me wonder what mine looks like now!

That is wonderful work. So can you solder "normal" steel like you would with copper lines, or is other work needed? Yes, I know I'm ignorant here.

Quote:

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Originally Posted by gimpyrobb

That is wonderful work. So can you solder "normal" steel like you would with copper lines, or is other work needed? Yes, I know I'm ignorant here.

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You can solder steel line and fittings, etc. In the case of using the coated steel line like I did, you need to strip off the galvanized outer coating before hand and get it very clean. I did braze the line into the fitting however as I noted above, because in order to heat the fitting enough to solder it back into the top of the tank, it would have melted the solder holding the pickup tube into the tank bung.

And yes, I wondered too, how many others look like that......Surprisingly, the inside of my tank was actually pretty clean with no scale or chunks of rust, just a very slight brown haze in there. I cleaned it with phosphoric acid and it came out like new.

Randy, I'm pulling up your old thread in hopes of getting some advise. I saw your post about melting the solder to pull the pickup tube.

I dont know how far that I need to go, so maybe you have a recommendation or two. I tend to sometime over complicate things, because I want to do it once, and hopefully the correct way

I pulled my tank today, and it doesnt look too bad. Its pretty shiny inside for the most part. Would you recommend an Ospho rinse anyway, will Ospho mix with the residual gas or do I need to hose it out. I"m not keen on that because I'm not sure where to dispose of the gas/water mix.

I can see the sock in the tank to well, but it doesnt look terrible. I do have a coil of 3/8 galvanized fuel line and a flaring tool, and could possibly do your mod.

I have the tank out, and mostly empty - what would you do? (WWRD) ha!

From my past experience with fuel tanks of that age/era, I'd say do the mod.

If you don't do it now, you will probably end up doing it later. With the addition of ethanol to fuel, it acts as a solvent and will wash off anything you cannot see inside the tank, and may attack the sock over time, softening it, or causing it to come apart and stop up the line later. That, and finding a leak/line issue later and having to remove the tank and do it again to me is just a pain.

Keep in mind that what you can see through the filler neck or sending unit hole is only the left side of the baffle that runs down the length of the tank, so there could be other stuff you don't see on the other side of it.

Its out now and on the floor I assume? That's the time to do it.

When I cleaned my tank, which wasn't too bad inside either, I used a mixture of water and phosphoric acid to clean it, then rinsed it out completely, and added a box of baking soda and water to neutralize the acid, before drying it out completely inside using a fan overnight. Disposal may be a problem, but phosphoric acid is used to clean concrete and other things too all the time and it gets rinsed onto the ground anytime I've seen it used in that application.. The stuff you'd rinse out of the tank should be negligible if there isn't any real loose stuff in there and all the fuel is drained completely. You could also use muriatic acid too, but it tends to flash rust very fast after using it.

Thanks Randy. Would using Ospho be on, or should i just buy the phosphoric acid.

I haven brazed since highschool welding class in 1984. Do you think I can get enough heat out one of those propane cylinders using map gas?

The baffle: is it brazed to the bottom of the tank, and where is the door/gate that lets fuel flow between them? I tried to look in the tank using my free NRA led flashlight, but it wasn't bright enough :D

I have read about the chain trick, and jeeper mentioned the marble trick to loosen up anything that I cant see. but I dont want to get a chain stuck in the tank

I haven't tried Ospho in that application, but its more of a rust converter than a rust remover. Phosphoric acid will also act as a convertor as well, turning the remaining surface in the tank black. It is the common ingredient in almost every tank cleaner I've seen, so I'd go with that just because its proven to work. You could also seal the tank afterward with something like Caswell's, but I didn't seal mine and just keep it full of fuel if it sits to keep condensation down.

The baffle is a solid plate in the tank, but the corners are open to allow fuel to flow to the opposite sides.

A hand-held propane torch, even with Mapp gas, may not get hot enough to braze with brass or bronze. It will probably require a oxy/acetylene torch to do the job.

ok, thanks Randy

Wow, I didn't realize you have been here 4 years already Randy. Time sure does fly. No, I normally don't look at the joint date because for those of us who joined before 2007. It isn't accurate due to several versions of the Zone crashing or changing.

Have you had any crud problems with the newer fuel sitting over winter in the tank?

That and my motormouth post count.......:D To be truthful, I rarely pay attention to that stuff either.

I've not had much problem with fuel in the large quantities like an automotive tank holds. Seems that small stuff like bikes, small engines, etc are the problematic stuff.

I keep my tank as full as I can most of the time, mainly for reasons you mentioned, but also in case a storm sneaks up, or I need the truck in a hurry. I've also been using the Star-Tron stabilizer religiously too.

Just an additional comment for what its worth,
I had good results rinsing the tank with diluted CLR .
I dont know what the active ingredient is but my tank cleaned up like a new penny with no rust issues at all.
I also try to only use non-ethanol fuel in all my small engines and the vehicles I don't want any trouble out of.
I querried my brother-in-law about the non-ethanol versus ethanaol fuel debate(he is a chemical engineer that makes a living producing ethanol fuel )
He verified that fuel mileage is 10% better on average using non-ethanol fuel and that it stores much longer than ethanol gas.
In fact the only good thing he could say in truth about ethanol gas is that it really cleans your motor (valves and whatnot) as the alcohol has a solvent effect in use.