VW LT35
I wish to add a small fuel tank to this 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 proportion of pumped fuel is returned?

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

I need to consider the situation when the main tank is full - if a small
amount of fuel 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