Like others mentioned there should be only air/vapors in the EVAP system and not liquid.
While at a gas station, do you have problems like the fuel pump handle shutting off while filling your fuel tank before it is full?

 

Juke, I have this issue. I need to refuel relatively slowly. No other apparent issues.

 

@Harvlr Could be a partly clogged breather or vent line, 11/12 in the diagram above. The best way to clear it is by dropping the gas tank remove the line and blow compressed air through.

The problem with the disco is you have no upper access to the breather but you might be able to get at breather from underneath without dropping the tank.

 

Thanks Richard, I've been avoiding the issue as I have suspected that I needed to drop the tank to fix it. I'll need to get at it sometime.