front brakes

One cause of the pistons not going back in to the calipers is corrosion. The caliper pistons get corroded and then get stuck in their bores. This is common in snow country or where it is very humid ( I think that MD qualifies for both ) As far the indentations on the back of pads, did you put these pads in yourself? What do the indentations look like? Do they look like the pistons, or the caliper brackets etc?