One problem related to brakes failed has been reported for the 2009 Hyundai Sonata. The most recently reported issues are listed below. Please also check out the statistics and reliability analysis of the 2009 Hyundai Sonata based on all problems reported for the 2009 Sonata.
My 2009 Hyundai Sonata with 15000 miles on it started to have noisy rear brakes. I took it to my local Hyundai dealer and was told that because this had been a rental vehicle it may have sat on a lot for an extended period of time and the "slides" froze in place not allowing the brakes to release resulting in premature brake and rotor failure. I believe this is a life/safety issue and should be a recall issue. I don't think a vehicle should have to be driven a minimum number of miles to prevent the brakes from failing in 15000 miles.