IT WAS A RAINY DAY. I WAS GOING APPROXIMATELY 30 MILES PER HOUR. THE CAR IN FRONT OF ME SLOWED. I DID ALSO. MY BRAKES WOULD NOT RESPOND ALTHOUGH I WAS PRESSING ON THEM. THE CAR STARTED SKIDDING AND WOULDN'T STOP. I CRASHED INTO THE CAR IN FRONT OF ME. THE DAMAGE TO THE OTHER VEHICLE WAS SLIGHT. LUCKILY WE BOTH HAD INSURANCE. THIS HAS HAPPENED TO ME ONCE BEFORE, ALSO WHEN IT WAS RAINING. I HIT A CURB THAT TIME. AT NO TIME DURING THESE TWO INCIDENTS WAS I DRIVING AT AN EXCESSIVE SPEED. THE CAR JUST REFUSED TO STOP.