Bleeding master cylinder in the car

Condensation.
The lines should be completely filed with fluid (along with the wheel cylinders, master and calipers) normally I would think of condensation as moisture that came out of solution from the air because of a drop in temperature. If the system is properly bled (no air bubbles in a system - a condition that would have its own issues) then there is nowhere for any moisture to be in the system at all, until something fails. I'm not a mechanical or chemical engineer, but I would hate for folks to not take an excellent remedy for an old problem if indeed there are no issues with the DOT 5. Ehrenberg, the tech editor at Mopar Action has been recommending DOT 5 for many years. I hope someone with some real qualifications can give us more info.