ENTERED 1ST LANE OF TRAFFIC , ACCELERATED AND ENTERED SECOND LANE. AT THAT TIME TRAFFIC SLOWED ABRUPTLY. APPLIED PRESSURE TO BRAKE, BRAKE PEDAL WENT TO THE FLOOR--PUMPED BRAKE, TOTAL FAILURE CAUSING ME TO HIT VEHICLE IN FRONT OF ME. APPLIED EMERGENCY BRAKE TO STOP VEHICLE, HOWEVER TRACTOR TRAILER WAS BEHIND HONKING HORN , CAME WITHIN INCHES OF HITTING ME. WITH EMERGENCY BRAKE APPLIED, FORCED TRUCK TO BREAKDOWN LANE. LUCKILY NO INJURIES--JUST CAR DAMAGE INCLUDING A NEW FRONT BUMPER THAT HAD JUST BEEN REPLACED DUE TO CHRONIC GM RUSTING. TOW TRUCK ARRIVED--DRIVER NOTICES SEVERE BRAKE FLUID DRAINAGE ON GROUND AND ON TRUCK BED WHEN RAISED UP. TRUCK BROUGHT TO REPAIR SHOP, WHERE MECHANIC REPORTED ALL BRAKE LINES BURST DUE TO SEVERE CORROSION. MECHANIC STATED--NO WONDER YOU DIDN'T HAVE ANY BRAKES BECAUSE ALL LINES FAILED--NOT SURPRISED DUE TO GMC HAVING BRAKE LINE ISSUES. NEEDLESS TO SAY--TRAUMATIC EXPERIENCE THAT COULD HAVE BEEN A LOT WORSE UNDER DIFFERENT TRAFFIC CONDITIONS. THINK ABOUT CHILD RUNNING ACROSS ROAD--TRACTOR TRAILER NOT BEING ABLE TO STOP IN TIME....HIGHER SPEED ON THE HIGHWAY-- THINK ABOUT IT--I CERTAINLY AM!!! *TR