brakes
 

I have a 2004 dakota and when I leave the truck for a couple of hours and then drive the back brakes will grab the first few times and then will be fine and it feels like the front dont grab like use to. I took the back drums off and compared the shoes to the new ones and they are like new so I cleaned them with brake clean. It was fine for like 4 days and now they are doing the same thing. Could the front brakes be worn out? or is there something that will cause this problem.