My vehicle 2008 chevy tahoe ltz 8 months old 16 k miles all 4 rotors had metal shaved and groves from the brake pads but the pads was 25 % worn. chevy resurface rotors and replace brake pads my concern is safety. is this a wide spread problem. according to my mechanic yes but they did not replace the rotors just resurface them. is there a batch of chevy rotors that have defective material? *tr