[T3] Update with a Bowl Full of Rust Flakes

Jim Adney jadney at vwtype3.org
Sun Jul 24 05:38:26 PDT 2011

On 23 Jul 2011 at 22:16, SCS Crewcab wrote:

> How does the full tank keep the gas from gumming up the pump internals?

Think about what happens to the gas in the gas can in your garage. No 
matter how old that gas might be, it never turns to gum. The reason 
is that can is sealed, so the gas can't evaporate. It could stay like 
that for decades.

No gum forms until most of the gas has evaporated. If the tank is 
full and the only vent line is a long, small tube, the time it will 
take to evaporate >9 gallons of gas becomes extremely long. I've left 
cars with full tanks for 2-3 years and come back to tanks that were 
still "full" and ran just fine.

My '71 gets run about every 2 years. In that time, I never see any 
sign of gum or that the tank level has gone down measurably in that 
time. I've never had any trouble restarting it.

My '69 has been in storage for 9 years. I hope it's okay, but I 
really don't know yet. I hope to get it out this summer, but I 
haven't had time yet. That will be a good test.

BTW, this is all with whatever regular gas I get at the pump: no 
stabilizer, and, at least in recent years, this has had some ethanol 
in it.  

Jim Adney, jadney at vwtype3.org
Madison, Wisconsin, USA

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