Rear caliper seized and service questions

Get a second opinion -- the caliper get get hung up on the pin vs the piston sticking. It may have destroyed the rotor or the caliper (heat). In your situation -- I would not replace the other caliper if the OE is available or an OE rebuilt. Often when the calipers go -- the car is old and the other side is not far behind or the caliper is different. If it was stuck -- you may be able to salvage the caliper.

The fronts can go down to 1mm -- you have time on them. Make sure all the front pads have the 3mm. Sometimes one can be less -- no point in trashing a rotor. Do you have a local mechanic? The chains like to change everything .. more $$

 

The rear brakes are complicated by the parking brake function. It's important that the pin on back of the inner pad locks in between the spokes on the caliper piston face. When the parking brake is applied, if the pin is not solidly locked between the spokes the piston will rotate, the pin will ride partially up on a spoke, and from then on the brakes will be partially jammed, and the pressure when they're applied will be uneven.

If this is happening the inner face of the rotor will have about 1/2 it's width unused and rusty, and the pin on the inner pad will look chewed up.

If you're seeing this, I'd try removing the rotors and "dressing" them with sandpaper or steel wool, clean and lube the caliper pins, and install new Toyota pads/shims. New shims are not mandatory, but they don't cost much.

At reassemble, it's crucial to rotate the piston so that the pad pin falls between spokes. After assembly press brake pedal multiple times to seat the pads, lock the pin. Then reconnect 12 volt (it should be disconnected at the outset). Then do a short test drive. Then apply parking brake as needed.

If the rotors had a rusty zone the brakes will likely be noisy at first. This may persist for a few days, gradually diminish. You can check if the drag has been fixed, by raising the rear and test spinning the wheels.

Again, this may or may not be the issue, but it's a cheap first step, needs doing anyway.

 

it's important to educate yourself, as you're doing here. the rear brakes can be funky as mentioned above. wherever you go, make them show you what they are talking about. take pics and post them here, if you care to. all the best!

 

Here's Toyota instructions on brakes, might help your mechanic.

 

all the best!

 

I do all my own work, and replace just what is necessary. No sense replacing a caliper that isn't bad. Replacement calipers are used refurbs anyhow, so I'd rather have my working OEM. The rotor likely needs replacement if the brake was seizing. This can easily be checked with a caliper to measure thickness.

I'm more comfortable having someone else change my oil, since the job is easier, and I can observe what oil they are putting in and verify the level. Brakes are more tricky, and it isn't as easy to see if they did it right. Not only that, but the service costs too much. For those reasons, I do 'em myself. Only basic tools are required, and in a pinch, you could even use the tire iron and jack that came with the Prius to do the work.

 

Toyota sells refurbishing kits for the calipers if it's needed, so if you don't mind a little DIY, you end up with your OEM calipers all refurbed with OEM-spec rubber for the same money as cheapo aftermarket refurbs; the kit even comes with a little pouch of the Toyota-spec, lithium base glycol grease.

For the rears, it's odd though, at least the online parts diagrams do not show a replacement for the seal around the parking brake shaft. All the other seals are in the kit. Seems like if there's ever a leak around the parking shaft, replacing the whole caliper is the only Toyota solution.

-Chap

 

sounds right, the slide pins should be inspected every 5k and lubed as needed.

 

5k is a bit much, every couple of years is reasonable.

 

Sounds like Mendel has made another successful addition to his convent!

 

Glad to hear -- if you read my description ... that is what I was talking about. The Toyota caliper design is subjects to sticking .. this is not usually a problem with cars used regularly .. used infrequently or those that spend time in a harsh environment have a greater chance of this problem. My cars are used most days and get inspected at least twice a year -- I have never had this issue.

I replace any questionable rotor -- not worth having any future issue.

Sound like you are on the correct track.