WHEN STOPPING SUDDENLY SOMETIMES THE BRAKES ON MY 2004 PRIUS WOULD NOT RESPOND IMMEDIATELY AS THEY SHOULD. THEY WOULD RELEASE THE CALIPERS COMPLETELY AND THE ONLY WAY TO STOP WOULD BE TO LET OFF THE BRAKES AND PRESS THEM AGAIN. IT DOES NOT HAPPEN OFTEN BUT IT IS REGULAR ENOUGH THAT THIS HAS ALWAYS CONCERNED ME VERY MUCH. TODAY I WAS FOLLOWING A CAR WHO SLAMMED ON THEIR BRAKES VERY SUDDENLY AND THEREFOR I ALSO HAD TO SLAM ON MY BRAKES. THIS SAME ISSUE OCCURRED AND I DID NOT HAVE TIME TO RELEASE THE BRAKES AND PRESS THEM AGAIN CAUSING ME TO HIT THE BACK OF THE CAR THAT I WAS FOLLOWING. I MAINTAIN MY CARS VERY WELL AND THIS CAR WAS IN TOP CONDITION WITH BRAND NEW TIRES. THE BRAKES DO NOT EVEN ACTIVATE ENOUGH TO SQUEAL OR LEAVE ANY RUBBER BEHIND. THERE IS NO WAY THAT I COULD POSSIBLY HAVE STOPPED IN TIME. THIS IS NOT SAFE AND NEEDS TO BE RESOLVED FOR OTHER PEOPLE WHO HAVE THESE CARS.