i was going on a camping trip and my friend was in front of me on the blue ridge parkway and it would randomly get very thick with fog, plus all the turns. well we pulled into a parking lot and as i was trying to stop my brakes went all the way to the floor with little pressure, ( luckily it stopped) but i got out and smelt something weird but i didn't see any leaks so i turned the car off and back on and a ways after that they were fine, and still are.I just had all new pads put on so its not them. Did they just get to hot?

 

Watch if it does it again. A bad master cylinder can allow the pedal to sink slowly & smoothly to the floor. Seems to happen more when it's real hot.