One problem related to brake sensor has been reported for the 2004 GMC Yukon. The most recently reported issues are listed below. Please also check out the statistics and reliability analysis of the 2004 GMC Yukon based on all problems reported for the 2004 Yukon.
Excessive rust build up on brake lines, rotors and calipers. Rotors & pads previously replaced in sept. , 2008. Needed replacement again in oct. , 2012 after only driving 16,000 miles. Brake lines are severely corroded and are in need of replacement. Control arm linkage attached to height sensor actuator also broke at about the same time.