brake problems need help

[essex0727]

well. its effing cold here in massachusetts. this morning it was like -6 degrees. so..... my brakes worked fine this morning but when i got out of class and was driving home my brake pedal has way more play to it than before. like almost to the floor. i could still brake somewhat but i had to pretty much stand on the pedal. so when i got home i did the obvious and check my fluid(full) and to see if there were any spots on my driveway where it had leaked but nothing, i couldnt see anything. so now im confused what may be causing this. also if it helps when i am not moving and i pump the pedal i get the pedal back but once i start moving its garbage again. is this having anything to so with the sub zero temperatures or is something wrong with the pedal its self.

[scotty-2-forty]

Try flushing/bleeding your brake fluid; it absorbs water over time and the water is responding to the cold. And be sure after a proper bleeding that your resevior is all the way to the line. Hopefully, you've never mixed DOT ratings when topping off (if you did)?