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Cause of seized brake caliper? Replace one or both brake calipers?

My 2004 Toyota Highlander with 84K miles has been diagnosed with a seized front driver side brake caliper with worn brake pad (1/32). I had recall work done a few days ago at the dealership and this was discovered afterward during the “complimentary” multi-point check-up. - You know, the long laundry list of recommended work they try to sell you on. Of course the brake work is actually necessary. The dealership estimate for this repair included only the one (LF) brake caliper, front brake pads, and machining the rotors to the tune of $535.

Since the vehicle was just inspected 2 months ago at our local shop, my husband suggested I take it back there to verify the diagnosis and see what that mechanic would recommend. That mechanic confirmed and showed me the seized caliper/worn pad, which, by the way, was functioning well in mid January at inspection, and measured 7/32. This mechanic recommends replacing both calipers, pads, turning rotors for supposedly discounted $598 and a “half-price” brake flush at $45, coming to a total of $643 plus PA sales tax. He said doing just the one caliper would save me about $140. There was no indication of a problem with the RF caliper, but he says it’s just a good idea to replace it so we would avoid having another problem in the future.

I want to ask everyone’s opinion regarding replacement of just the bad caliper vs. both. Are we getting ripped off as far as the estimate and is the flush necessary? Also, is this issue typical in the first place, and what causes a brake caliper to seize? We’ve had several other vehicles driven many more miles than my Highlander and never experienced a seized caliper.

We’re hoping there’s no relationship between this issue and the recent vehicle inspection, as we’ve come to trust this mechanic’s work.

Thanks in advance for any advice you might provide! ~ Judy

Calipers can seize two ways. Either the caliper hardware ie slides/guides corrode where the caliper gets stuck. Or, the caliper piston seizes and won’t retract when the brakes are released.

If the problem is with seized hardware this can be replaced with a caliper hardware kit without replacing the caliper. If the piston is seized in the caliper then the caliper requires replacement.

If the caliper piston is seized then I would replace both calipers. The reason caliper pistons seize is from brake fluid contaminanted with moisture. So if the caliper piston is seized, replace the brake fluid.


I’d replace both. My reasoning is as follows:

-If one failed, since they are both identical parts, manufactured and installed at the same time, the other may fail at any time.

-If you replace just one, it may have different characteristics than the old one–eg. it may respond a little faster than the remaining old one when you step on the brakes causing a pull to one side or cause the car to briefly ‘dart’ to one side or shimmy until the older one catches up.

I would also have the brake fluid flushed and replaced as Tester recommends.

If you live where prices are high, it’s a fair price. The last Toyota Camry caliper for an 83 model that I priced was over a hundred dollars so I got one from a junkyard for ten. Nice day for me. The salvage yard may have none for your model and in Pa. if they did have one it would be rusted in place. Where you live, you need both replaced. I lived in Ca. in Lompoc and Bedlo’s or Bedloe’s was my favorite salvage place. Wish I were there and if you know what I know, so do you.

If the pad that is worn down is the outer pad, the the caliper seized because of the bushings (aka pins but Toyota calls them bushings). Neither caliper needs to be replaced but the bushings on both sides at the very least need to be removed, cleaned and re-greased. Sometimes it is best to just replace the bushings, they don’t cost that much.

If it is the inside pad that is worn, then you have a stuck piston and that caliper should be replaced. I’d just do the one, but in all cases, do get the brake fluid flushed. That is important.

I do think the mechanic said the caliper piston was involved, Tester. So it sounds like the general concensus is to have both calipers replaced, after oblivion and pleasedodgevan2 gave input as well. Thank you for your replies. Still somewhat disappointed with the estimate and think it’s mighty steep. We don’t live in or near a big city, just a fairly small town that seems to have quite an abundance of mechanics. How much labor time should this whole job take if we have both calipers replaced, new front pads, machine the rotors, and flush the brakes?

So your vote would be to replace just the one caliper, Keith. Hmm…

When the pads and rotor wear the piston extends out of its bore and can become cocked under hard braking. When the piston becomes cocked in its bore it can notch the bore and the cylinder rim can notch the piston. Once that has occurred the caliper is no longer safe as it will be apt to leak at the seal and be prone to seizing. And brakes is one area where it is better to be safe than sorry. Many years ago I rebuilt calipers and have dismantled seized calipers and the un-seized caliper from the other side and usually found similar damage to both sides. And if the stuck caliper is caused by a collapsed hose it is wise to replace them in pairs also.

I disagree with replacing both. If the other one fails, it won’t do so catastrophically - i.e. it won’t make you get into a wreck. So if the other one fails, just take it back in and have it replaced too - you won’t get a discount for replacing both at once, so at best you’re saving a little time, and in all likelihood you’re wasting a couple hundred bucks because the other side isn’t any more likely to fail than any other symmetrical part.

After all, if the logic is to replace both calipers because they were both installed at the same time… Well, after all, all 4 calipers were installed at the same time, so why not do the whole car?

Then there’s the extra charge of bleeding the brake system twice if the other caliper fails.


That’s true, but that’s not all that much. Or is it? I confess I’ve never paid for a system bleed 'cause I’ve always done it myself.

The prices seem within reason. But there are some other issues to consider.

Replace both calipers? It depends on whether cheapo non-OEM brake components have ever been used on this car. If non OEM brake pads for example were installed prior to this incident, it is quite possible the pads resulted in the damage to the caliper, or an improper install job in which the components were mis-aligned or all the mating surfaces not lubed with high temp grease contributed to the failure. In that case I’d replace both calipers and I’d also replace (rather than re-surface) both rotors.

If all the prior brake work has been done with OEM parts and done per Toyota spec, including the brake part lube requirements, then I’d only replace the one stuck caliper, and leave the other. However, I’d still opt for new rotors. Turning rotors on newer cars is tricky, and can result in brake jobs that need to be redone in just a few months.

With a stuck piston my vote would be for replacing its partner on the other side. Just like wheel bearings, struts, or what have you, if one side is a problem the other side is usually not far behind.

Besides, one would hate to spend that kind of money only to have the non replaced caliper piston stick a few weeks later and wipe out the new rotor and pads on that side.

There is yet another way calipers can seize… The piston is sealed from the outside world by a rubber boot. If this boot gets damaged, water / salt can get between the piston and its bore and corrosion causes the parts to seize…I would replace them both and be done with it…And yes, bleed / flush the brake fluid for sure, front and rear…

I guess the brake “bleed” is the same as “flush”, right? That’s what my mechanic said he’d do front and rear for 1/2 off - usually charges $90 and said he’d give me a break at $45. Still sounds like a lot to me, but then I have no idea how long it takes.(?)

And GeorgeSanJose, I searched my records, and have never had front brake work done at all on this vehicle, only rear (which were non-OEM, though) :frowning:

So then can you all actually identify the specific cause of the seized caliper upon visual inspection? Or you just have to assume it was due to one of the reasons several of you have detailed?

Replace them both so the pads will wear evenly.

You can’t visually check a caliper piston and determine if it’s stuck or not. Attemping to compress the piston back into the bore will reveal if it’s stuck or not. A piston in a good caliper will compress with what could be called firm ease. A piston in a problem caliper will either not compress at all or it will be difficult.

Other than corrosion on the piston and piston bore in the caliper, the usual cause of a problem caliper is the rubber seal inside the caliper has hardened. The profile of the seal is square and the flexibility of the rubber itself is what causes the piston to return to its original position after letting up on the brake pedal.
Hardened rubber may not allow that to happen with an aged caliper. As an analogy, think of a spring that has lost its springiness. :slight_smile:

Yes, all 4 calipers were installed at the same time, and by that logic, the back ones are as likely to fail too. But you wouldn’t put two dissimilar tires on the front of your car, why would you want two calipers that may perform differently? The exception would be with a car that’s only a few years old–in that case I would just replace one. If the car is older than that, I’d do both.