One problem related to brake disc rotor has been reported for the 2004 GMC Sierra. The most recently reported issues are listed below.
2004 GMC Sierra pickup truck, notice brake problems at about 12,000 miles took truck to dealer to see what problem was, concerned was wearing brake rotors in front end, was told that rotors were defected from manufacturer thy were turned wrong at factory, they tried to correct problem by turning them at dealer problem returned at 30,000 miles, went back to dealer to correct problem then front rotors were replaced and rear rotors were turned also, again at about 34,000 miles problems with rear rotors occurred they refused to warranty them I feel that there's a wider problem then just a few truck and s. U. V. And a recall and a inspection should be done on all rotors from this year of manufacturing should be done for safety reasons I did save the rear rotors for measurement in the future if needed.