Rear brake pad question

Thanks, Mendel! I did check that yesterday, too. The wheel spins fairly freely, but as you can see in the pics, the pad wear is extremely lopsided; at least 6-7 mm left on the inside pad, but the metal is touching on the outside edge of the outside pad. Whatever I do, I'm going to get a pic of the pad once it's removed so that I can show how lopsided it was. The wear is such that 0 mm remain on the outer edge but 2-3 mm remain on the inside edge (visible in the last pic above).

I don't know if this is telling, but if I drive it now, there's no sound until I brake enough to engage the pad. It squeals when braking, and then the squeal seems to remain for a minute or two after I accelerate again.Then the squealing eventually subsides. Makes me think the caliper isn't releasing properly. I should find out soon enough, once I make up my mind whether to replace them myself or take my chances with a different shop.

 

Take it apart and check it out. You'll think it over to death on this forum. You should be able to figure out what's going on in about 20 minutes. If not, take it to someone professional and move on with life.

Based on your last post, I'd say your e-brake is fine and you have a sticky slide pin or the pads are hung up in the carrier and not moving properly. Cleaning and greasing as appropriate and you should be good to go with new pads.

 

Well, I went ahead and changed my rear brake pads myself after spending the time thinking about it. Wholeheartedly encourage anyone who's sitting on the fence to go ahead and DIY. Very simple job. Certainly doable in an hour. Having a significant DIY population helps keep the dealer somewhat competitive and reduces their monopoly power.

Thank you @Mendel Leisk and @NutzAboutBolts ! Based upon the dealer lying that the rotors were the source of the problem, I would've needed to earn $1,000 pre-tax to cover their invoice.

The squeal was of course the pad, not rusty rotors. And, I found the root cause of my brake pad wear:


Turns out the pins need to be straight in order to prevent them from hanging! I suppose this could've happened when my parking brake froze solid in February and I tried to move the car with the brake still engaged. Had to call a couple dealers to find the pin, but ended up being successful. $17.99 for this essential component.

Got my pads from the dealer, and as I noted elsewhere, there appear to be a few different varieties in use for the Gen 3:
OEM Brake pads | PriusChat

I used the 08887-01206 grease from Toyota for the pins and a little packet of copper anti-seize for the shims. Piston tool worked great, got the piston face oriented properly (like an X, not a +), and I did not loosen any bleed screws or brake reservoir lid. I did disconnect the battery before and press the pedal after I finished getting the car back together before reconnecting the battery. And I put a rag over the hatchback latch to prevent accidentally locking the hatch with the power off.

No more squeal, hopefully good for tens of thousands of miles more now!
Thank you all again for the great tips!
Cheers,
Rob

 

For what it's worth, I installed cross drilled and slotted rotors and ceramic pads. Interesting things is now my plug-in battery charges faster when braking compared to the OEM parts on the car.

Toyota Prius Drilled/Slotted Rotors and Ceramic Brake Pads in the Back - black_jmyntrn

Toyota Prius Drilled/Slotted Rotors and Ceramic Brake Pads - black_jmyntrn