[T3] Update with a Bowl Full of Rust Flakes

[Jim Adney]

On 24 Jul 2011 at 14:30, SCS Crewcab wrote:

> I just can't picture what you're talking about. I think I understand one 
> end of the passageway running under the cup opens into the void of tank. 
> Where does the other end open? Into the return tube, into the cup, where 
> specifically? Also is there a diagram or a discussion on the function of 
> the passageway in the literature?

Here's the link to the drawing on Dave Hall's site:

http://home.clara.net/hallvw/fuelsend.htm

Scroll down to find the drawings of the tank. I see that he's added a 
view of the carb style tank, which I'm not familiar with. It also 
shows a small passage that you wouldn't want to clog up with a tank 
sealant.

> I'm new here so, maybe I just don't understand how the tank works in 
> general. The tank I have has an opening at the very bottom (lowest 
> point)  of the tank.  To this opening there is a nut with a fuel line 
> that connects to the suction line of the pump. This is the opening that 
> has the copper fuel sock filter. There is separate opening at the bottom 
> of the cup that connects, via a tee, to the return side of pump. This 
> connection does not have any filter at all.  Due to the law of gravity, 
> all the gas in the tank (except the small amount remaining in the cup) 
> would have to empty through that opening. Is this not correct? If the 
> description is correct, what keeps 3/8 of the gas in the tank from 
> flowing through that opening when the hidden passageway becomes clogged?

The port with the hex nut is where gas flows out of the tank. The 
second port is where gas flows into the tank. The gas can't get into 
the pump from that direction. Since gas can only get out of the tank 
and to the pump via the first port, it must flow thru that small 
passage in order to get to the outlet port once the tank is below the 
~3/8 point. (I'm not actually very confident about the 3/8 figure, 
but the cup extends some distance up into the tank.)  

Take a look at the sketch and let us know if this helps.

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