Looks familiar. I was working with our shops' "truck driver" years ago and he decided the 40 ft flatbed trailer needed new all four wheel brake pads. He was out there putting new pads on for about six hours before going on a pick up. When he came back, he said something was wrong with the trailer brakes and could I have a look at it. I just layed underneath and looked. There were NO rotors on the front axle at all. He had put all four sets of pads on backasswards. The owner was not a happy camper. And the truck driver got the opportunity to look for a new job. And guess who got to repair all the brakes?