Re: Larry's 1951 Club Sedan Project

Posted by Larry51 On 2015/8/18 19:17:26

Thanks for your suggestions gents . . . and apologies for my delay in responding.

I blew air (and also sucked air) by mouth through the breather tube and there was just a little bit of resistance so there is no major blockage. But there was no whistle either, so something is amiss with the system. I would expect a whistle to happen even when using my lungs to suck air through. Likewise, no whistle happens when I rapidly pour the gas in from a can. Gas goes in quickly without backing up in the neck, probably as quickly as if it was being pumped from a bowser, yet no whistle is heard. Yet there is a whistle fitted to the tank (- judging from photos I've seen).

So - why doesn't the gas back up in the filler neck when I pour it rapidly from a gas can? It flows in quite OK, so it would seem the breather tube is OK(?)

Or maybe the very small amount of resistance to air flow is causing the problem.

My tank was (thankfully) un-rusted, and looked metal-shiny after a clean, so no 'gunk' was needed. So the whistle must be a dud it seems.

I can only surmise that the problem is not a vent tube blockage, but due only to the gas station pump 'switch-off' mechanism constantly switching off as bubbles back up the filler neck.

My question is: do US petrol pumps use the same switch off mechanism of bubbling gas coming up the filler neck?