One problem related to brake disc pads has been reported for the 2004 Chevrolet Trailblazer. The most recently reported issues are listed below.
When checking my brakes I noticed that the inside of the front brake rotors where corroded and rusty. The vehicle is a 2004 Chevrolet Trailblazer with 32,262 highway miles. Approximately 25-30% of the inside of the rotor were rusted and had worn down the brake pad. So only 70% of the inside brake pad was being used for braking. This causes the brake pads to wear unevenly. Appears that this could be serious in an emergency situation. I checked the rear rotors and they are starting to do the same but only 1/2" on the outer edge of brake rotor is rusted. I checked the recalls and there were none for brakes. I checked with chevy and they are not aware of any problems. In checking websites, Trailblazerclub and trailvoy, other people have had the same or similar issue. I would assume that there is a problem with the metal.