Rear brake uneven wear

When you have the wheel off the car and nothing else undone you should be able to grab the caliper assembly and push it side to side at least the thickness of the padware or if you can't figure out what that means or I'm talking about undo the caliper remove the pads set them on the ground now slide the caliper back up on the pins You should be able to use your finger and push the caliper away and back towards you sliding the caliper along the pins with one maybe two fingers If it's so stiff that you got to use your hand or smack it with the back of your slip joint pliers or something like that for the caliper to move that is incorrect You need to push the caliper back off the pins clean off the pins with some crocus cloth or very smooth sandpaper wiping away with a rag the filings from the sandpaper obviously and then I use a small dowel bigger than a toothpick to pick out the nastiness old grease out of the rubber boot and the bore that the pin slides in then I spray that out with pick your poison carb spray degreaser something and I get all the pieces of that nasty grease and BS out of the hole that the pin is going to go into and then there is brake grease that is available wherever or you can buy Toyota's red whatever just use whatever you buy so buy enough that you don't have to use a little of this and a little of that You should use the same thing to do the complete set of pins on each caliper then when you do this now you put the caliper back on and one finger you'll be able to push it across the pin and pull it back all the way in push it back pull it in no problem light drag now your pads should wear evenly any doubt replace the pins they're like six bucks a piece the whole assembly.

 

I inspect with every tire rotation, so every 6,000 miles or so, and I typically find it takes more force, like my hand, pretty much every time at that interval. But one back-and-forth like that wakes the grease right back up and it moves easily after that.

The grease can get kind of peanut-buttery from lack of motion, because when you think about it, your inspections where you push the caliper back and forth are the only times it moves more than about a quarter mm at a time.

If I wake the grease back up easily, and find no damage on the rubber boot, and the pins move smoothly and greasily after that, I don't bother taking the boots off or the pins out or doing anything more with the grease.

If I find damage to the rubber boot, or feel any roughness in the pin movement or resistance beyond just waking up the grease, then I'll go further.

 

Could be improper caliper piston alignment; that one bit me. See rear brake drag in my signature. On a phone turn it landscape to see signature.