remove filler from Le Mans gas tank

[mikeyr]

So, I need to remove the gas tank fill cap and also the gas tank fuel supply from my old tank and move it to new tank.

I find no screws and the filler cap seems to be welded to a part that is attached to the tank, there is a bead on the inside that sure looks like weld. I will grind that down but I also need to re-use the part attached to the tank, I assume its a threaded part that the filler screws onto. In order to not blow myself up, I will cut the piece from the tank so no fumes go BOOM, its been 40+ years since the tank had gas in it, but it still stinks. Does anyone know if that part attached to the tank is brazed on or something stronger. I need to move those parts to my new tank as the new one did not have them or even the attachment parts. Just wondering if someone has done this before to save me experiment time.

[Peter McKercher]

Mine was soldered on

[tvdwerf]

Before to use any fire in the old tank, just clean with water.
I did it also with mine, after I found out the outgoing pipe was blocked.
It is possible the old coating will burn, but not give a boom.
Another option is when you only need a part, and the rest is scrap: drill a hole in the tank, ad use a hand cutter from that hole out.

[casadecabra]

Yes, mine was soft soldered on. Interesting logistical problem as to the original fitting procedure - presumably the tank was painted after soldering on the filler cap and masking it off.

I re-painted my tank and had the filler re-chromed, then Locktite-ed it place with bearing fit grade, which will hopefully resist petrol.

David B

[Peter McKercher]

David
What do you mean by loctiting it on with bearing fit grade. Does that seal it from gas leaking through? Is loctite not a liquid. How did you keep it in place until it cured?

[casadecabra]

Peter
I used Loctite 641 described as a retaining compound, because I had some to hand. It is reasonably viscous and has gap filling properties but there are probably more suitable Loctite products ( https://www.henkel-adhesives.com/uk/en/ ... ounds.html ). It sets in around 25 minutes so the filler cap just needs temporary support during this period.

David B

[mikeyr]

For future reference
It is soft solder. Easily removed.

My fuel tap plug won’t come out. Too much crud under it. But I will get it out. But who plugs up the fuel tap permanently?

The fuel cap is soft soldered on and also riveted on

I tried to fill my tank with water but too many holes, but ran a lot of water through it. So knowing it’s been 45 or more years since fuel was in. I used a propane torch. No boom. Probably not safe but wanted the stuff off the original tank. I will cut the top off and grind the rivets from the underneath so as to not damage the flange.

[mikeyr]

And for more reference. The fuel tap has a nut inside the tank. So after cutting the top of the tank off I was able to remove the fuel tap bushing. And had to grind the rivets down to remove the fuel cap part.

Not sure how I will proceed now. I can put the fuel cap in with self tapping screws on my new tank or reach in and put bolt nuts. Then solder.

But the fuel tap one I will not be able to put the nut on the inside. I suppose solder only will hold it.

I was under the mistaken impression that the fuel cap was threaded and it’s not. I do need a new fuel tap though. Think the one I have is pretty bad. Maybe I can fix it but if I can find better I will

[Peter McKercher]

Hardwicks have them in stock Mike

[mikeyr]

What he has for a fuel cap is threaded though. But I already emailed him about the fuel tap and lots of other parts

[Peter McKercher]

I assume if the cap is threaded so is the after market gas tank filler hole

[Phillip]

Early caps were soldered on. Later caps, commencing sometime perhaps in mid - to - late 1935 are screwed on.

[mikeyr]

Thank You, so I have a early. I was able to get everything unsoldered and will fit to new tank. The fuel tap won't be screwed down and soldered, just soldered, I am guessing they put the fuel tap on before sealing up the tank. Maybe even the fuel cap part but that one I can bolt in by reaching in the tiny hole and then solder it all up.