Brake fluid is hygroscopic, meaning it attracts water even inside the hydraulic system. This is why all European car manufacturers recommend a brake fluid change interval, usually 1 year or 2 years.

Traditionally, bleeding your hot rod's brakes requires three people: One to pump the brake pedal, a second to work the wheel-cylinder bleeders, and a third to referee the inevitable brawl between the ...

I think the accepted way for a one-person bleed is to fill a tube with fluid and place it in a resevoir of more fluid. As the pedal is pumped, it will bubble air out but draw fluid in.