2002 Dodge Durango front brakes smoke and cant go over 40 w

Owne a 2002 dodge durango 4.6L. It has about 89,000 miles on it. Just bought it used. Recently when I drive it the front brakes begin to smoke, I can not drive faster than 40-45 miles per hour, it gets worse when the car heats up. Smells like buring rubber. Supposly the barkes where replaced before I bought the car in feb of 2008. What could it be, it get everything from the calipers to the brake pads? What could it be help. Want to drive my car.