Gas tank replacement 1972 questions

[Charles P.]

I have just received a new tank from Quanta. My car has the sender on the bottom. Once I remove the spare tire cover it will be pretty much exposed. Will I need to remove the boot around the filler neck on top of the tank or will it just come down with the tank? Also when I remove the neck from the top of the tank and install on the new tank will I need to use a gasket sealer on the cork gasket? Can I install the rubber boot on the neck and make my connections and lift into place?
Any reason I need to siphon the bit of gas that is in there first before dropping it down? I was thinking I could drop and leave the sender in, then stand up and remove the sender (its a new sender so I will swap onto new tank)

Thanks for any other tips

[Joe L.]

Re: Gas tank replacement 1972 questions

I have just received a new tank from Quanta. My car has the sender on the bottom. Once I remove the spare tire cover it will be pretty much exposed. Will I need to remove the boot around the filler neck on top of the tank or will it just come down with the tank? Also when I remove the neck from the top of the tank and install on the new tank will I need to use a gasket sealer on the cork gasket? Can I install the rubber boot on the neck and make my connections and lift into place?
Any reason I need to siphon the bit of gas that is in there first before dropping it down? I was thinking I could drop and leave the sender in, then stand up and remove the sender (its a new sender so I will swap onto new tank)

Thanks for any other tips

Charles------

The filler neck seal ("boot") can be left installed when the tank is removed. It is "attached" only to the filler neck.

No sealer is used on the cork gasket. Most sealers, especially silicones, are not impervious to gasoline. I much prefer to make up a gasket for the filler neck using buna-n sheet rubber. The cork gasket can be used as a pattern. Always use new screws. These screws have an integral gasket and the gasket will usually be deteriorated on existing screws.

If there is only a small amount of gas in the tank, you do not have to first remove it. However, you have to remove the rubber line between the sender and the frame fuel line so you might as well drain the tank at that time. Of course, you can just clamp the line and leave it attached to the sender but it's just as easy to drain the tank then. After draining, clamp the rubber fuel line still attached to the sender so that you don't get any fuel remnants to leak out as you remove the tank.

[John S.]

Re: Gas tank replacement 1972 questions

Charles, in addition to Joes comments, which I 100% agree with, depending on your exhaust system configuration and muffler type, you may have some clearance issues getting the tank to drop straight down.

In the past I have found you can gain some additional clearance by releasing the clamps back at the exhaust tips and leave the system sag down a bit. Once lowered, make sure you support the system with some blocks, don’t leave it hanging on its own unsupported. This will give you additional clearance to take the tank to one side then drop the other.

The second tip I can give you is take a good look at your new sending unit if it is a reproduction. Check the seal of the sending unit connection as it goes through the round base of the unit. After about 2 years my reproduction developed a slight leak and I found it was sealed on the interior with a type of fiber washer. The connection is easy to unscrew from the base and I replaced the fiber washer with the proper size O rings on both sides of the base - no more leaking unit.

Good luck, if this is the first time the tank has been down, you may find a copy of the build sheet glued to the top of the tank.

[Owen L.]

Re: Gas tank replacement 1972 questions

No sealer is used on the cork gasket. Most sealers, especially silicones, are not impervious to gasoline. I much prefer to make up a gasket for the filler neck using buna-n sheet rubber. The cork gasket can be used as a pattern. Always use new screws. These screws have an integral gasket and the gasket will usually be deteriorated on existing screws.

Just food for thought...

I recently pulled my '72's tank to clean it from 30 years of storage, install a new sock and filler boot, and replace all hoses. Upon installation of the cork filler neck gasket I put a thin coating of Permatex gasoline-proof sealer on all mating surfaces. I also had to tap the neck's attachment holes flat from someone in the past over-tightening them and distorting the filler ring's holes.

As to the gasket-ed screws, I discovered mine were like tiny o-rings, that were easily removed, revealing a cupped underside to the little bolt head. A visit to the hardware store and I had a new set of tiny o-rings that fit perfectly.

[Charles P.]

Re: Gas tank replacement 1972 questions

Thanks to everyone, the tank is in and all buttoned up. Did not know it but Quantas also supplied the fuel sender gasket, fuel neck gasket and the 9 fuel neck screws with the rubber o rang gaskets. I don't know if they do this with all the tanks they supply but I now have extra. Unfortunately there was very little if anything left of the build sheet. Mostly what was left was a strip about 1 inch wide and 6 inches long which was the exact bit that had glue on it. Very happy with the results and the tank is mirror shiny on the inside again versus the "atomic orange" slurry it had degraded to. Now what fuel additive to keep it that way??