Shortly after I got my car (5 years ago) we went on a road trip abroad, and starting hearing a loud metal rubbing noise. We found a mechanic who spoke enough English, and they said the brake pads needed replacing, which we did and it fixed it. I wasn't too clued up on mechanical stuff then, so didn't pay too much attention. However the person we bought the car from said they'd replaced all the brake pads recently (maybe they did, maybe they didn't). About this time last year I got a similar noise. I took it to a trusted mechanic and one of the rear brake pads had gone rusty. He replaced both rear pads with a better quality set (€25 a set instead of €15 ), greased everything up properly and sent me on my way again. We checked all the pads, and they had only worn down about 1/3 in 60,000km. I live in the city and don't drive too much, so he put it down to the car getting wet and then sitting without the brakes having dried out. Well this week I've started hearing a similar noise, so it seems like the same thing is happening. It's the same wheel (rear right). After a short trip yesterday I checked and this rotor was hot, while the others were cold. It seems a bit too much of a coincidence for it to randomly happen again on the same wheel, so quickly, so what other things should we be checking? It seems unlikely to be an issue with the parking brake sticking, as I never use it. The rotors are rusty around the edges, but the part where the brake rubs is clean.
Check the sliding pins and also check if piston is in X position. Mendel will come with docs for sure. I've had a similar problem and my pads were stuck. Don't know why, they should move a little when mounted but mine were not. I must force them out and grind a bit their "ears" with an angle grinder. No problems since then (a couple of months).
Your problem is likely to return- I often see rust buildup underneath the stainless steel shims on the caliper brackets where the pads go. Rust expands as it forms, pressing against the pads until they seize. You have to remove those shims and cleanup all the rust- usually I take the brackets off the car to do this. A few times I had the brackets in a vice and needed to use a hammer to beat the pads out. Posted via the PriusChat mobile app.
Just tapping on a phone, docs not that accessible, but: The rear pad backing plates have a stubby pin that MUST be located and locked between the raised spike pattern on caliper piston. Accordingly, during assembly the piston should be like an “X”, and then the brake pedal pushed multiple times, get everything seated. Then do a short test drive, and only afterwards apply/release parking brake a few times. then raise the rear end and verify both wheels are semi-freely spinning.
