In May of '17 we bought a new Rockwood 1970ESP. It was used extensively until just this year (next trip scheduled for Sept) but while getting it ready to go, I noticed I could no longer lock up the brakes on the unit even with the tlr brake gain control on the tv set to 10 (it usually is set at 4 to 5 and would lock them at 20mph as per instructions). Current tv is a '19 Silverado Z71 with tow package. I went to Les Schwab and they told me brakes were fine after $160 worth of "work". The problem was still there and they would not look again saying they don't do electric brakes. I finely found someone who knows what they are doing and was told that both the drums and shoes were badly glazed. My guess is that I have 15k to 20k miles on this pup although in fairness it goes up and down a lot of mountain passes. The tech has also replaced some bushings and some other parts on the running gear (not the springs though) leading me to believe this pup is not as off road capable as I had hoped, but is it me too? My question is this: What is everyone else getting mileage-wise out of a set of brakes?