While this should be a non issue it is happening to allot of these, many with only 20k miles on them. What is happening is the rear caliper bracket is rusting so bad it wedges the pad and they never release and drag the whole time you are driving. If you have even low miles on your explorer I urge you to take a look, I walk you through the whole process in my video. One thing to note here is brake warranty only goes to about 12k miles not 36k miles as most assume so after the 12/12 period this would not be covered which puts the expense back on you. In this video I also show you how to be proactive and prevent it.