BRAKES DO NOT WORK WHEN IN REVERSE OR AT LOW SPEEDS. PROBLEM WAS THERE THE DAY I PURCHASED THE VEHICLE. A COUPLE WEEKS AFTER PURCHASE I BACKED INTO VEHICLE IN A PARKING LOT. I WAS TOLD IT WAS "NORMAL" AFTER ALMOST HAVING A WRECK I DID SOME RESEARCH. HOW IS THIS NOT NATIONALLY ADVERTISED AS A RECALL YET? THIS IS A HUGE SAFETY NEGLIGENCE ON GMC'S PART. THE VACUUM PUMP IS KNOWN TO FAIL BY EVERY DEALER I HAVE CALLED. ALSO EVERYONE I KNOW WHO HAS THE SAME MODEL TRUCK ALSO LIVES WITH THIS PROBLEM.