What could cause inside only of brake rotors & pads to wear down but not outside on 2005 Pontiac Montana

changed rotors and pads 15,000 miles ago and the inside of the front rotors are worn, and the pads are almost gone, but the outside of each one is fine. This is on both sides in front

Asked by for the 2005 Pontiac Montana
If the caliper has corrosion and is not sliding properly on the guides, then only one side of the pads will do all the braking.
The calipers seem fine
1 more answer
Check the flex hoses, these hoses over time collapse inside and cause the pads to remain pushed out even though you release the brake pedal. The hoses are really cheap approx. 15 dollars per side.