New pads and discs after 20k miles?

That issue has come up here too, especially in areas that have winter snow conditions and heavy use of road deice salt.

The friction brakes don't get much use in normal driving, and can corrode. If you park outside the problem is worse. Looking around at regular cars you will notice the rotors are shiny and clean. With a lot of Prius cars, the rotors appear to have corrosion on them

Some have suggested getting up to about 50-60 km/h and - in a safe place - shifting into N and firmly braking. Do that a few times and the rotors should be cleaned

 

But rusted rotors doesn't explain worn pads/discs or the screeching when not applying the brakes. Assuming you brake with your right foot and not with the off foot in some way that invokes the friction brakes while cruising, I'd be concerned that the brakes are failing to retract after use.

Now I'm just an accountant, but I'd check the pads (cautiously) for temperature after a little town driving. They should be touchable, unlike non-hybrid brakes. They only get used below 8 mph and in hard braking, so some have found virtually no wear after 100M miles.

 

Are you a left foot braker?? Sounds pretty fishy

Icarus

 

20k for a brake job is way to early. I'm at 124k on my '05 and still wondering when I'll need new brakes. Seems it might last over 150k. I'm a pretty hard braker too as I drive faster than I should. I think as long as the dealer notes the issue and if it ever comes up again, even after your warranty expires, it should still be under warranty. That is what happened to me when I had the brake actuator making a noise, which was more like a grinding I believe. Good luck.

 

Out of curiosity, what did the dealer offer in the way of explanation for why the brake rotor and pads needed replacing? Worn beyond minimum tolerance? Warped rotors? Corroded rotors? Or????

Something is definitely amiss.

ksstathead, I wouldn't go around touching rotors or calipers after driving the car and applying the brakes without first confirming the absence of heat (such as by squirting some water on the rotor or caliper). You could get a third degree burn for your efforts.

 

Hi Hobbs,

The only thing I can think of is if some foriegn matter got wedged between the pad and the disk. Like a small piece of hard stone (grannite ? Ironstone - like they use for railroad balast ? ) . Continued driving with that screeching would wear a groove in the disk, which is required to be replaced by law if the groove is too deep. Toyota might have requirements for replacing disks in a set to have straight line braking action, too.

 

At the 40,000 miles service, I was advised that the car still had 85% of the front brakes pads and 90% for the rear.

 

Sticky calipers are a possibility. That would keep the pads in light contact with the disk even after you take your foot off the brake.

 

Or something is wrong with your brake calipers and they're rubbing the pads against the disk all the time.

 

The brake pedal is connected to a hydraulically actuated spring to give it a "normal" feel. Pressure in the hydraulic portion is relayed to the computers to determine braking action. There is also a potentiometer on the brake pedal arm that is used to measure the rate of pedal actuation. This signal is also fed to the computers and used as an indicator of panic braking. When you press on the brake pedal, these two inputs are used by the control system to decide what type and how much braking to use. When possible, the Prius does all of its braking by regeneration. It can't do this at speeds below eight mph, or when the HV battery is too full, at which point the friction brakes are used. Friction braking is also used in a panic stop or when the traction control system detects that the front wheels are slipping during braking. Backup braking power is suppied by a bank of super capacitors in the back of the Prius. The brake lights are actuated by another switch on the brake lever arm, and are not directly connected to the brakes in any fashion.

Tom

 

It sounds like you msy have a TOE-IN ALIGNMENT problem. Have your checked out too. This is the silent cause of lots of brake problems. Almost like High Blood Pressure in us Humans. A silent killer.

 

What does TOE-IN Alignment have to do with the brakes?

 

+1. I could see where the Toe setting had an impact on tire wear, but brakes? I am real curious to hear how the Toe setting causes pre-mature brake failure.

 

dito, would only effect tires and in sever cases side trust on bearings, but no more than cornering..

 

I had the same, the squealing was a loose brake pad in need of some high melting point grease on the back to keep it stuck to the piston and away from the disc. It would give a very high pitched squeal at low speeds, but only below 40mph and this would stop when I applied the brakes. A good emergency brake test from about 10mph would often stop the squeal for a few days. The garage replaced the front pads and discs free of charge at 30,000 miles but that wasn't successful, and then had another go with the grease at 40,000 miles which did the trick. Perhaps the summer floods washed the original grease away.

 

Like the other poster said my 07 has very slightly rusted calipers too. Very odd as they should be shiny metal. Prius brakes should last long time. But maybe yours are very very rusty and maybe the pads have a rust film on it. Google " Bedding new car brakes". That particular thing is not related to the Prius exactly but will help in understanding brake weirdness. Or maybe your rear brakes are whacked out and not contributing to braking at all. If I was going for new fronts I would make sure they take the hubs off the rear and inspect them too.Somethings not right. Please take a picture & post of the rotor surface. Its easy to see through the hubcap.

 

Nearing 70K miles here . . . over 70% left on the pads. The Roters look even better.