VW LT35
I wish to add a small fuel tank tot his madel (deisel).

The existing tank has a flow and return line, so that excess pumped fuel 
is returned to the tank.

Can someone advise what peroportion of pumped fuel is returned?

I wish to ann a 7 litre tank - but for simplicity to connect only a flow 
pipe - excedd fuel being returned to the existing tank.

I need to consider the situationwhen the main tank is full - if any a 
small amount of fure is returned - this will not be a problem 
considering the size of the additional tank.

Also, can anyone advise on taps/shutoff valave for use on a fuel line, 
so that I may select which one is "open"?

Thaks

Eric