Started to notice my 2016 making a squealing sound last week. The sound would come and go, but was pretty constant whether i was on the brakes or not, and sounded somewhat like a brake pad wear indicator.
This seemed odd as I knew my pads weren't that old but I pulled the front tires to have a look and noticed that the passengers side outer pad was nearly completely gone. The inner pad still had a lot of life left in it and the drivers side pads looked fine.
My first thought was a frozen piston/bad caliper, but when I went to replace the pads i had no problems pushing any of the pistons back. There's also no noticeable pull in either direction when braking. I thoroughly greased the slide pins just in case they were causing a hang up, but they were greased well before I took them apart. I do get a bit of high speed vibration in the brakes, but I assume this is most likely slightly warped rotors.
Now that there are fresh pads in there I'm going to continue to monitor the wear. Is this most likely a bad caliper? I'm not eager to just start replacing expensive parts like that in the hope I'm replacing the right part. I had the fluid replaced by the dealer a few months back, is it possible they introduced some sort of contaminant into the system that has blocked fluid somewhere? Not sure were to go from here.