Looking at the rotators and brake pads on my truck, I believe the reason the passenger side pads failed prematurely was that there was a stone trapped between the rotator and brake pad. The stone became embedded in the pad, and lead the pad to wear unevenly, so that one of the pads on the passenger side front wheel was so worn down on one corner it was virtually metal on metal. There was a deep — 2+ mm deep groove in the rotator and a matching deep pock mark in the inside corner of the pad where the rock was embeded. Little piece of gravel from a dirt road. Who knows how long that rock was in there — I noticed the groove several years back but didn”t think much about it — but it continued to grind it way away.

Sucks. But at least it wasn’t that expensive to fix, the truck is quiet, and the brakes work well.