Two problems related to brake master cylinder have been reported for the 2005 GMC Yukon. The most recently reported issues are listed below. Please also check out the statistics and reliability analysis of the 2005 GMC Yukon based on all problems reported for the 2005 Yukon.
Started car in the morning to go to work. As I do every day. Foot on brake as usual, shift to drive, to begin a turn in my driveway, in making the left turn, which is a downward grade, applied brake, which went to floor. No resistance whatsoever, complete failure of brakes. Kept foot on brake and steered up the grade, then put car into park. Got out, opened hood. Checked master cylinder- no fluid visible at usual line. Checked under vehicle, brake fluid trailing on driveway under path of vehicle, and slow drip from under forward front driver side . Brake lines and connector completely corroded and rusted. Had I been on the road I would have been unable to stop, vehicle is driven by my son as well. Our lives and those of others in the vehicle as well as others that mead been in our path were clearly in danger. This problem should not occur, and is completely unacceptable.
: the contact stated while traveling 15 mph, the vehicle's brakes failed and the contact had to use the emergency brake to stop the vehicle. The service dealer replaced the master cylinder, but this had not corrected the issue. The brakes had failed on two other occasions, but the dealer could not find the problem.