BRAKE PEDAL TO FLOOR NO RESPONSE ON STEEP HILL ALMOST KILLED. RESORTED TO EMERGENCY BRAKE. 180 HALF TURN INTO OPPOSITE LANE. NEARLY HIT WALL BUT AVOIDED GOING OVER CLIFF AT END OF HILL.. HAPPENED THREE TIMES PUMPED TO GET BRAKE PRESSURE SUBSETQUENTLY USING LOW GEAR TO GET TO A SAFE LOCATION. BRAKE FLUID OF DOLLAR RENT A CAR WAS IN BETWEEN FULL AND MINIMUM. CAR HAS 23000 MILES APPROXIMATE. INCIDENT RESEMBLES NO OTHER VEHICHILE EXPERIENCE I HAVE HAD. MASTER CYLINDERS DID NOT PROVIDE PROPER PRESSURE. USED LIGHT BRAKING AND WAS ON MOUNTAINOUS TERRAIN. RECOMMEND INVESTIGATION. DEATHS WILL ENSUE IF NOT DEALT WITH THIS OBVIOUS DEFECT. VEHICHLE WAS IN MOTION AT 60KPH DOWNHILL STEEP WITH SHARP TURNS. NISSA VESA WAS SOLD AS TIIDA LIBERIA, COSTA RICA DOLLAR RENTAL CAR FLEET).