COMING HOME FROM WORK AROUND 5:00 IN THE AFTERNOON AND WENT TO SLOW DOWN FOR TRAFFIC SLOWING DOWN AND BRAKE PEDAL WENT TO FLOOR AS I EASED DOWN ON THE BRAKE PEDAL. TO KEEP FROM HITTING THE TRUCK IN FRONT OF ME I HIT THE EMERGENCY BRAKE PEDAL AND WENT TO THE RIGHT SIDE OF MY LANE AND HIT A GUARD RAIL SLIGHTLY DAMAGING MY FENDER AND BUMPER BEFORE COMING TO A FULL STOP. I GOT OUT AND LOOKED UNDER THE TRUCK AND FOUND BRAKE FLUID LEAKING FROM ABOVE THE FUEL (GAS TANK) ALONG THE INSIDE OF THE FRAME RAIL. I CALLED AAA ROAD SERVICE AND HAD MY TRUCK TOWED TO MY HOUSE SO I COULD FURTHER INSPECT THE TRUCK FOR REPAIRS NEEDED. I AM A DIESEL TRUCK TECHNICIAN AND HAVE BEEN WORKING ON CARS AND TRUCK FOR YEARS. I ALSO HAVE A 1989 CHEVY TRUCK WITH 368,000 AND NEVER HAVE HAD A BRAKE LINE REPLACED OR A BRAKE FAILURE LIKE THIS, AS I INSPECTED THE BRAKE LINES I FOUND ALL STEEL BRAKE LINES ARE CORRODED AND RUSTED AND NEED REPLACED. I KNOW THIS IS GOING TO BE A COSTLY REPAIR! I PULL A BOAT, TRAVEL TRAILER AND A UTILITY TRAILER. IF I HAD BEEN PULLING ONE OF THESE ITEMS AND THE BRAKES HAD FAILED LIKE THEY DID ONLY GOD! WOULD KNOW THE OUT COME. GM NEEDS TO MAKE A RECALL AND HAVE THIS ISSUE FIXED. I AM BACK DRIVING MY 1989 STEP SIDE UNTIL I CAN AFFORD TO MAKE REPAIRS! I SURE COULD USE SOME HELP!!