AS I WAS MAKING A TURN AFTER A STOP (WHICH FELT SOMEWHAT SLUGGISH OF A STOP) I WENT TO TAP THE BRAKES AND EXPERIENCED COMPLETE LOSS OF BRAKES. I WAS ON A DESCENT AND IMMEDIATELY THREW THE TRUCK INTO PARK TO CUT THE POWER TO WHEELS AND PRESSED EMERGENCY BRAKE WHICH WENT ALL THE WAY TO THE FLOOR. THE BRAKE PEDAL WENT ALL THE WAY TO THE FLOOR AND I HAD A SPLIT SECOND TO DECIDE WHAT TO DO AS THE ROAD WAS CAUSING RAPID ACCELERATION. I SAW ONE CHANCE TO DRIVE OVER A DITCH AND INTO A YARD BY A HOUSE. I DID SO, FLYING OVER THE DITCH. IT TOOK THE LENGTH OF THE ENTIRE YARD (ABOUT AN ACRE OF PROPERTY) FOR THE TRUCK TO EVENTUALLY STOP ON ITS OWN. I HAD TO HAVE IT TOWED WHERE UPON QUICK ASSESSMENT MECHANIC SAID I HAD CORRODED BRAKE LINES AND RUPTURED BRAKE HOSE. THIS MOST CERTAINLY COYLD HAVE REAULTED IN A FATAL ACCIDENT AS THE END OF THIS ROAD IS FULL OF HOUSES AND SHARP BEND WITH MULTIPLE TELEPHONE POLES. I AM STILL AWAITING FULL REPORT ON VEHICLE BUT AM VERY UPSET GM HAS NEVER EVER ADVISED ME OF THIS KNOWN ISSUE. I MAINTAINED VEHICLE AT GM DEALER AND AM SINGLE OWNER. NEVER ONCE WAS I NOTIFIED. MY VEHICLE HAS A LITTLE OVER 100,300 MILES ON IT AND I WAS JUST STARTING DOWN THE HILL, ABOUT 10MPH BUT RAPIDLY THE VEHICLE ACCELERATED WITHIN SPAN OF 2 HOUSES...RESULTING IN THE CRASH AND LOSS OF VEHICLE USE DUE TO NEED FOR TOWING. HAVE NO IDEA OFBSPEED AT THE DITCH AS I WASN'T ABLE TO LOOK DOWN .