# Gas Tank Replacement



## wings012345 (Sep 10, 2014)

Hey Everyone. I'm replacing my gas tank. I bought a new one which did not come with the neck. Does the neck come off easy from the old to install on the new or is it welded on?


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## PontiacJim (Dec 29, 2012)

According to the OPGI catalog I have, it states that the original neck is soldered on. I suppose you have to unsolder it and re-install onto your new tank.

However, I would be very cautious with heat in/around any gas tank that previously had gas in it. I've never had to unsolder a gas tank neck or put one on, so I can't offer any sound advice on this one - and I hate explosions and hospital recovery times.


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## leeklm (Mar 11, 2012)

If you apply heat or flame to a gas tank... FIRST, rinse it out good with water. THEN, fill the tank with water up to just below the line you will be brazing or applying heat. By filling with water, you displace the gas fumes out of the tank. If you only "rinse" the tank, or have large open air pockets with no water, there will still be plenty of fumes that can explode.

Another possibility with the filler neck... I adapted a new 72 Tank (with elec pump) to my 73 GTO. I filled the old tank with water as noted above, then used a saws-all to cut the neck at the appropriate spot. The new tank came with a rubber adapter/hose and hose clamps that were used to connect my old filler neck to the new tank. It worked quite well.


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## Guy B (Apr 29, 2015)

I've seen most (if not all) tanks for 68's listed like this.....is there a reason? Seems if you buy a fuel tank the filler neck should come with it.


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## 68Resto-mod (Nov 10, 2009)

I don’t know why but you can’t buy a new tank for a 68 that has a filler neck included. The filler neck is soldered in and is easily removed with some heat from a Bernzomatic touch. It is really no different from “sweating” copper pluming pipe. 

1 - Drain as much gas out of the old tank as you can

2 - Remove it from the car

3 – Stick the garden hose into the tank and let it fill and then overflow for 5 or 10 minutes. Gas is lighter than water any residue will float to the top and out. Drain out the water and let the tank sit in the sun till most or all of the water has evaporated. Stick your nose into the filler neck and give it the sniff test. Smell gas?,,,,,,rinse it out again. However, it should be clean after the first rinse. As an added precaution, I took my air hose with a blow nozzle and blew air into the tank to purge any trace of gas fumes just before applying heat to the solder joint.

4 - Take a reference measurement from the end of the filler neck where the gas cap sits to some point on the top of the tank that will also be common to the new tank like a bump, ridge or something like that. You will use this measurement to insure that the neck is in the right spot once it is soldered into the new tank. Also put a reference mark on the neck to indicate witch end is “up”. 

5 – Apply heat from your touch (I used MAP gas, it burns hotter) to the old solder joint and you will be surprised how fast the old solder melts and you can pull the neck out of the old tank. Have a clean/damp rag near buy so you can swab the excess solder off of the neck end while it is still hot. Leave a thin coat of solder on the neck. This will aid in “sweating” it into the new tank.

6 – Note that there is a ridge around the tank end of the neck that seats into the hole of the tank. Dry fit the neck in the new tank and see how it puts it at the correct angle when fully seated (remember the measurement you took earlier?). Have someone hold the neck tight into the tank and verify the distance from the end of the neck to the reference point on the new tank.

7 - Prep the hole in the new tank with some 0000 steel wool. I also put some soldering flux on this surface to insure the solder will bond. Use plumber’s flux core solder.

8 – Position the tank so the hole is somewhat level. Now insert the neck into the tank with the flange seated. Make sure the neck is not rotated from the “up” position. Have a helper hold the neck in place and double check the reference measurement. Apply heat from your torch directly to and all around the neck and tank where they join. Bring your solder in against the solder joint (not in the torch flame). When it starts to melt, let the solder flow all around the joint. Keep it hot but not hotter than required to melt the solder. Don’t be afraid to use a little extra solder. There should be a molten river of solder around the base of the neck. Some solder may drip into the tank but this is harmless. The fuel pickup screen will prevent any from entering the fuel line.

9 – Shut down your torch and (if you have a compressor), blow some air on the joint to cool it. 

10 – Re-install tank, connect hoses, fill with gas, go do burn-outs.

Enjoy!


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