thumping noise at rear

hello...My wifes 2000 chrysler town and country has recently started making a thumping noise when applying the brakes and does so until complete stop. I layed the back seat down in order for me to get my ear down to the floor to listen because it is hard to tell whether its from the left or right or center...It appears to be coming from the rear passenger side wheel area. As soon as the brakes are pressed the thumping starts but slows as the car slows down and the noise gets a little quiter the slower you get.

It sounds like your brakes are not being applied equally. Check and make sure there is no air in the line (bleed the brakes) or you may just need new brake drums/shoes.