Plugged gas tank outlet

[Grumblebuns]

Has anyone successfully unplugged a gas tank outlet tube? I  had my TCS gas tanks refurbished by a local radiator shop last summer. They were suppose to check my outlet tubes for blockage and ream them out if necessary. Unfortunately, when  picked the tanks up, I was in big hurry and didn't bother to ask if they had to unplug my tanks. Now eight months later, I'm getting ready to re-install my tanks and I discover that they are still plugged. For the last couple of weeks, I've been trying to get the tube unplugged by using a stiff flexible wire and a combination of PB Blaster, WD40 and carb cleaner. There is absolutely no evidence that any of the solvents have any effect on the plug. After two weeks of no progress,  I'm almost ready to cut off the outlet tube at the tank transition and using a drill bit to ream out the obstruction.

Anyone have any other ideas before I get this drastic

[SilverBeast]

I've never heard to deal  with this, but I'd be tempted to carry on with your stiff flexible wire in the chuck of a cordless drill and hope that the rotation of the end would abrade the blockage rather than than the tube.  Possibly even try an old clutch/throttle/hanbrake cable inner in the drill so that the frayed ends of the strands act with a wire brush effect on the tube, you could even support the cable with a length of outer cable to allow you to keep the cable stiff between the drill and right up to the inlet of the pipe. Without looking, an old bicycle cable may even allow the outer cable to sit inside the diameter of the tube so the inner can be supported up to, or close to the blockage,  you could also reduce the outer diameter further by  stripping back the plastic outer sheath.

[Pfreen]

Why not take it back to the radiator shop who did the cleaning and sealing originally? 

[Grumblebuns]

I don't remember the conversation I had with the shop when I dropped the tanks off to get refurbished, obviously something got dropped when I told them what I wanted done. My assumption was that the hot tank process would clean out the obstruction. Before taking the drastic step of cutting off the plugged tube, I'll drop by the shop and see if they have a mechanical method of clearing the tube. With regards to my method of trying to poke the obstruction out, the most difficult part was figuring out what type of wire would be flexible but strong enough to withstand the hard poking, I came up with using the thickest string from an electric bass guitar Unfortunately the plug in the tube is like concrete.

[GavinT]

I figured a bass guitar string should work with a bass guitar pickup but maybe not a fuel pickup. 

But on that 'note' (sorry), would a short length of throttle or clutch cable mounted in a drill work?

[Grumblebuns]

Nice chuckle Gavin. Unfortunately I don't have a spare clutch cable  to test out. I'm thinking that a throttle cable may be too flimsy to work, also don't have a spare throttle cable. I'll keep working on it.

[Bainford]

Is the outlet plugged with an application of a tank liner material, or was it plugged before bringing to the tank shop? I ask, because my Special, on which the original tanks have never been removed, has a significant restriction on the outlet of the right tank. If the tanks are full and I attempt to drain them both, one will empty in a few minutes, whereas the right tank will take an entire afternoon or longer to drain. Similarly, if I fill both tanks and drive until the fuel gauge says empty, the right tank will still be half full.

I have tried poking at the obstruction, to no avail. It seems like a hard blockage, and I wonder if it is solder or brazing filler used during the manufacture of the tank. Could this be the problem?

[Grumblebuns]

My tanks were sitting for 20 plus years with gas still in the tanks. In my case, the old gas evaporated out until only a gallon or so of foul smelling stuff remained. What ever was left apparently slowly built up a very hard crust. There is no liner material in my tanks. As you've found out, poking the obstruction has almost no effect. The outlet tube sticks out into the tank about 3 or 4 inches and maybe a 1/2" off the bottom so it would be difficult for any foreign material to get into the inlet.

This morning I gave my efforts and brought my tanks down to the radiator shop. Per the shop, the hot tank process is suppose to dissolve the gas residue but apparently they either didn't blow out the tubes after the hot tank or there was insufficient time in the hot tank. They'll hot tank both gas tanks again. You can bet I'll be checking that both tubes are clear this time when I pick up the tanks.

[jpane]

Well, the only "bright side" of this I can see is that at least you had not reinstalled them.

[dakazman]

   First x 2 on what pfreen said.
     I used a small amount of muriatic acid on my heater shutoff valve that was frozen solid. The diluted acid loosen and dissolved the debris inside.  It will dissolve any rust and leave a black coating on the bare metal.  Dilute with water and also flush with water. Available at your local pool supply store.

Dakazman

[LotusJoe]

Try MEK (methyl ethyl ketone) if you can find it here in California. If you still can't get them cleared up your more than welcome to drop them at my shop.

[4129R]

I used copper electrical wire and compressed air to free mine.

I have cleaned and painted 14 tanks, and checked them all. Only 2 were blocked and copper wire worked.

The tubes go about 8" into the tank, they are about 3/4" above the bottom to avoid picking up sludge, so you can look for the wire coming through with a torch from the filler or from the tank level sender hole. 

[Grumblebuns]

To finish this thread up,  I picked up my tanks this afternoon from the radiator shop. According to the head cheese running the shop, they hit hard obstructions in both tank pickup tubes when investigating the plugged tubes. Using compressed air, both appeared to be mostly to partially obstructed, one wosre than the other. With the hot tank treatment not able to clear the plug, they were forced to cut off the tube at the tank and found weld material in both tubes, one worse than the other as can be seen in the photo. I always assumed that the pickup tubes were one piece but the shop thinks that the weld material was introduced when the outer tube was welded to the inner tube at the tank transition. They completed drilling out the obstruction in the inner tube, rewelded another tube to the tank and verified that the tube was clear. The final step was to have the tank innards coated with Red Kote fuel tank liner.

It seems that Trevors problem was not an isolated case.

[Pfreen]

Your car should go a lot faster now!  I am glad the rad shop took care of it.

[BDA]

Amazing! I'm lost for words... I'm surprised your car even ran before! I'm glad you got it fixed!