With the brake master fluid William, my main concern is that it does just sit there and often for prolonged periods. DOT3 does likes to absorb moisture, so once a year I like to suction out the old brake fluid and replace it to the same level it was before. Of course having some brake fluid /copper content reading test strips is a good idea ! Phoenix Systems - Brake Strip
I just replaced all the pads/turned rotors on the PA and it has been 1 year now with the fluid in there without bleeding at all 4 corners. I guess I am due to remove the brake fluid in the PA & 4x4 again just as preventative maintenance.
It is interesting to use a clear glass bottle to place the old fluids into. It gives you an indication how the old fluid really looks, but dip your strips first anyways!