I WAS DRIVING ALONG A 3 LANE STRETCH OF DIVIDED ROADWAY IN THE FAST LANE. I APPROACHED A NEW INTERSECTION, THE LIGHT CHANGED TO RED AND CARS IN ALL THREE LANES AHEAD OF ME PROCEEDED TO STOP. I APPLIED THE BRAKE PEDAL AND IT IMMEDIATELY WENT TO THE FLOOR. BEING IN THE FAST LANE AND TRAVELING AT 55 MPH WITH A CONCRETE DIVIDER WALL AND NO SHOULDER TO MY LEFT I IMMEDIATELY DOWNSHIFTED WHILE HOLDING THE PEDAL TO THE FLOOR AND CUT THE WHEEL HARD TO HEAD ACROSS LANES OF TRAFFIC. THE REAR END FISHTAILED OUT TOWARDS THE DRIVERS SIDE BARELY MISSING THE LINE OF TRAFFIC IN THE FAST LANE. LUCKILY I HAD ENOUGH DISTANCE TO SLIDE THE CAR SIDEWAYS FACING SLOW LANE SHOULDER, AND THEN CUT THE WHEEL OPPOSITE TO AVOID THE CARS IN THE SLOW LANE. I BARELY GOT AROUND THEM AND FISHTAILED THE BACKEND THE OPPOSITE DIRECTION IN THE SUBURBAN AS IT GRAZED THE GUARDRAIL. AT THIS POINT THE BRAKES WERE STILL OUT, PEDAL TO THE FLOOR, AND I TRAVELED THROUGH A VERY BUSY INTERSECTION UNDER CONSTRUCTION (RT 24 AND RT 95) STILL ROLLING AT APPROXIMATELY 30 MPH. I GLIDED ALONG THE SHOULDER SEVERAL HUNDRED FEET IN LOW RANGE GEAR WITH PEDAL MASHED TO THE FLOOR BEFORE USING PARKING BRAKE TO STOP! ONCE HOME I INSPECTED THE BRAKES AND THE BRAKE LINES AS OTHERS HAVE FOUND, ARE CORRODED BEYOND BELIEF. I LIVE IN MARYLAND AND WE SEE ICY CONDITIONS, BUT I FIND IT HARD TO BELIEVE THAT A VEHICLE AS HEAVY AS A SUBURBAN WAS EQUIPPED WITH BRAKE LINES THAT WOULD CORRODE AWAY TO NOTHING. ALL THE LINES RUNNING ALONG THE FRA