HAVING ISSUES WITH BRAKING. OCCASIONALLY AT HIGH SPEEDS, BUT MORE OFTEN DURING LOWER SPEEDS. THE BRAKE PEDAL BECOMES VERY HARD TO DEPRESS AND MEANWHILE THE VEHICLE IS STILL MOVING, NOT ALLOWING YOU TO STOP. HAPPENS ALSO GOING IN REVERSE. HAD A COLLISION, HIT THE REAR END OF ANOTHER VEHICLE YESTERDAY MORNING DURING RUSH HOUR, 3/18/2019. I WAS SLOWING DOWN TO 15 MPH, DUE TO A RED LIGHT, BUT BRAKE PEDAL WOULD NOT BRAKE, BECOMING VERY STIFF, MAKING IT IMPOSSIBLE TO BRAKE, AND STOPPED DUE TO THE COLLISION. LUCKILY NO ONE WAS HURT. FRONT BODY SEVERE DAMAGE TO MY TAHOE. POLICE REPORT HAS BEEN FILED. WE BOUGHT THIS TAHOE IN FALL OF 2017, AND FEBRUARY 2017, TOOK INTO THE DEALERSHIP DUE TO THE BRAKING ISSUES, NOTHING WAS FOUND OR DONE TO THE BRAKE SYSTEM. TAHOE IS BACK AT DEALERSHIP AS OF TODAY, AND NOTHING HAS BEEN FOUND, ACCORDING TO CHEVY TECHS