MY 2017 GMC SIERRA DENALI HAD ALREADY BEEN THE SUBJECT OF THE RECALL RELATING TO THE BRAKE ISSUE. SHORTLY AFTER THEY PERFORMED THIS RECALL WORK THE BRAKES BEGAN FAILING AT LOW SPEED. WHEN DRIVING BELOW 5 MPH, THE PEDAL WHICH SUDDENLY FALL AND THE ABS WOULD TRIGGER. DURING THIS TIME, THE CAR WOULD CONTINUE MOVING WITH THE ABS FULLY VIBRATING. THANKFULLY, MY TRAILER HITCH ABSORB THE REAR IMPACT AGAINST A WALL. THE PROBLEM CONTINUED. I THEN TOOK THE TRUCK IN FOR SERVICE AND THEY REPORTED THAT THERE HAS BEEN A SIGNIFICANT FAILURE RATE OF THE VACUUM ASSIST. THE DEALER REPLACE THE VACUUM PUMP AND VACUUM LINES. I'M EXTREMELY CONCERNED THAT THIS WOULD HAPPEN TO SOMEONE ELSE NEAR AN INTERSECTION, NOT JUST SLOWLY BACKING INTO PARKING SPACES. I HAVE CONTACTED GMC BY EMAIL BUT STILL HAVE RECEIVED NO RESPONSE OR ACKNOWLEDGMENT OF MY COMMUNICATIONS.