For those who have this portable compressor and as the title says, is there a way to correctly empty the water from the tank instead of turning the unit upside down to drain it directly (which could get messy and water could seep into the internals) from the refilling cap? There is nothing stated in the user's manual about doing this. I would like to flush the liquid that came with unit and replace it with a 70/30 water-coolant mixture. Also, not stated precisely in the manual is greasing the piston; which needs turning--the brass knob or the bigger silver aluminum knob atop which the brass knob sits? This is also not stated clearly in the manual. I've looked online to no success.
