Caliper Diagnosis & replacement

looks kinda steep to me (even including the labor)

2010 TOYOTA PRIUS 1.8L L4 ELECTRIC/GAS Caliper | RockAuto

 

The biggest way to tell if a caliper needs to be replaced or not is to look for uneven wear of the inside and outside brake pads on that caliper. Many times just taking it apart and cleaning/lubing the pins the caliper slides on is enough. If one caliper piston was stuck and not applying the brakes on that wheel then the brake pads on that wheel would be worn much less than the others around the car. Since all of your brake pads around the car seem to be even, I'm wondering too how the dealership determined a caliper is bad.

 

I would love to think that they did do this, it turns out to be valuable diagnosis to do and can quickly identify two different failure modes for calipers, one where the piston gets outright bound up, and another where it moves smoothly enough but doesn't retract by the proper fraction of a mm when the brakes are released.

In the thread linked above, I was doing the test on the bench with caliper removed, but I think it should be possible in situ and without introducing air, and I've suggested a way to do it—though I'm still waiting to hear from anyone who's tried it. Would only need some hose, a bit of compressed air, some blocks of a hard material with holes drilled through, and a dial indicator with a suitable-length extension, and a small amount of make-up brake fluid.

I would love to think the dealer did this test, but I'm confident they didn't, and generally wouldn't, as courtesy checks wouldn't involve anything with even that much labor.

It's certainly in reach of a DIY-minded owner, though.

-Chap

p.s. any problem you do find with a caliper, unless severe, can likely by cleared up by a simple go-over of the caliper you've got with a new rubber kit from Toyota. Another thing a dealer isn't likely to do, because their tech is done with the job faster by slapping in a new caliper out of a box. DIY, though, it saves you both the overkill of a new caliper when it isn't needed, and the irony of replacing a quality original caliper with an often cheaply rebuilt third-party one.

-Chap

 

how many miles on her? are you in the rust belt?

 

I would ask them what makes them think there's a frozen caliper....? Rotors are even left>right......

Do you have any mpg loss indicating brake drag?

Dealers suck.

 

Dealership is not being very forthcoming. They say there's a problem with one caliper, but don't volunteer which. Or what the problem is exactly. And make the suggestion to replace all four?? I can kinda see to replace either front or rear pair, but...

 

I would ignore the recommendation from this dealer. They need you to help pay for their boat payment

 

For calipers, you don't have to replace them in pairs, you just replace the one that is frozen. To determine if the caliper is frozen, you want to check if the piston moves in and out or not, uneven pad wears more indication of frozen sliding pins.

 

It's pretty easy to notice a piston that flat-out won't move (or that you need a C clamp to move, even with the bleed screw open), or flat-out stuck slide pins.

It's a little more involved to check for a piston that moves easily enough, but just doesn't have the proper return when the brakes are released. It's only about a third of a millimeter. (That is, just, visible to the naked eye if you're really watching for it, but a dial indicator will make it obvious.)

On the other hand, if you have a test method able to reveal lack-of-return, it will also be able to reveal a stuck piston. Both things do happen; lack-of-return was the whole explanation for a brake-drag issue I had in 2015—and that was on a newly-installed, 3rd-party reman caliper right out of the box, so the test is worth doing.

-Chap

 

I just regreased brake pins second time after 40,000 miles since the first time, and some of them were hard to move (the grease hardens and yes, I use the proper OEM grease). When i was younger and not familiar with cars I did pay for a few "frozen calipers." In retrospect, it could be avoided by simple pin greasing.

 

Hey OP....what ended up happening?