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Brakes making noise

Discussion in 'Gen 2 Prius Technical Discussion' started by Chris11, Dec 7, 2008.

  1. Chris11

    Chris11 Member

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    I now have just over 3000 miles on my 2009 Prius. About 200 miles ago the brakes started to make a noise like the pads were without pads, just metal, so when applied they'd sound like metal to metal contact. (Harken back to when we were young and didn't have the money to replace brake shoes when needed.) :)

    I took the car into the dealer from where I bought it and two hours later they said there had been rust on the rotors and that the rust had gotten into the pads. They said they sanded the rotors and the pads clean and they're now good. It was true, no more noise. When asked how they got rusty this fast the service manager said he didn't know, maybe when coming over on the boat. And he said they'd never had that problem with any other Prius.

    Just today, one week later, I noticed the sound had returned...metal to metal rubbing, only from the front it seems.

    Has anyone else heard of this or experienced it and does Toyota's explanation make sense.

    Thank you.
     
  2. direstraits71

    direstraits71 Member

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    Haven't had the same problem, but I have observed that the brake discs will form a thin layer of rust in the time it takes to wash the car. Next time you brake it will clean it off. The disc metal rusts almost instantly. I assume its the alloy that they're using as I have seen this on my Solara also. Never caused any permanent squeeking or noise or affected the braking since it cleans off with the first application of the brakes. I suppose if your car is parked outside in a damp climate and isn't driven for a long time the rust would be pretty heavy.
     
  3. firepa63

    firepa63 Former Prius Owner

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    Keep in mind that with regerative braking, the pads don't contact the rotors until about 7 MPH. Therefore, a thin layer of rust can build up quite easily. It normally clears itself after a while. In the 5 years I owned my 04 I never had to have the brakes serviced and so far so good with my 09.
     
  4. qbee42

    qbee42 My other car is a boat

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    This is a pretty standard problem. The brakes don't get used enough to stay clean. This is covered in several other threads, but I will repeat it here: From time to time it's a good idea to force your Prius to use the friction brakes. Pick an empty stretch of road, drive up to about 40 mph, shift into N, then apply the brakes and slow down to about 20. Shift back into D and repeat this a few more times. Using the friction brakes will clean the rotors. Do it as often as necessary to keep the rotors clean.

    Tom
     
  5. Chris11

    Chris11 Member

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    Thank you for your answers.

    I'm relieved ... not wanting this problem to show it's ugly head once the warranty has finished.

    And your answers do conform with the way I drive the car .... planning ahead and trying to stay off the brakes as much as possible. The noise does only seem to show up at very very low speed (less than the 7 mph mentioned.) And when I back it out of the garage each morning.

    And I'll try what you suggest qbee42.

    Thanks again.
     
  6. hadjibandit

    hadjibandit New Member

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    Chris11, i get a similar noise (08 prius) when applying brakes when the car is at low speeds. It does sound like some metal parts are rubbing against each other. Did you get it fixed? what did you do?


    Also, each time I get this noise while applying the brakes, as I release my foot of the brake pedal I feel a little jerk in the brake pedal along with a bit of the same noise.
    I checked with one dealer and he couldnt reproduce it when testing the car. He said it might be the way the braking system works in prius.

    Sometimes the sound is very annoying and I am taking the car to a different dealer in a few days.
     
  7. Betelgeuse

    Betelgeuse Active Member

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    If you haven't yet, try what Tom (qbee42) suggested earlier in this thread. It sounds like you are having similar problems that may be fixed by "polishing" the rotors with the pads.
     
  8. Chris11

    Chris11 Member

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  9. Patrick Wong

    Patrick Wong DIY Enthusiast

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    I'll leave to you the question of illegal vs. not in your local area. However it is certainly possible to shift to N from D, while you are underway.
     
  10. DrDee

    DrDee New Member

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    I had a similar intermittent noise problem with my brakes and when I took it to the workshop the mechanic found that grit had lodged between the disk and the brake shield. After a second visit he got the rest of the grit out and the noise has disappeared.
     
  11. abq sfr

    abq sfr New Member

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    Could also be the common rock-in-the-rotor syndrome. Happened to me last year, went away after a day or two. I wasn't too worried after reading about it here, must be fairly common.
     
  12. Slartibartfast

    Slartibartfast Senior Fjord Architect

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  13. donee

    donee New Member

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    Hi All,

    Many states have laws that you are not allowed to put the gears in a transmission into neutral while driving downhill. But as your not doing that when you put the Prius into neutral mode, it does not seem to be illegal by the letter of these laws. The Prius transmission always has the gears engaged even when the car is in park. Shifting the Prius transmission control does not change the position of the gears in a Prius transmission at all.

    These laws are far older than the 70's. Mechanical transmissions , especially non-synchronised manual transmissions cannot be forced back into gear if the speed between the engine and drive shaft become too different. Syncros were invented in the 30's or 40's by Ferdinand Porshe, so the law is older then that, I believe. The safety aspect is without engine drag, brakes can overheat. Overheated brakes will boil the brake fluid and result in loss of force. Hot brakes could also catch the brake pads on fire, resulting in loss of braking. And hot surfaces tend to be more slick - socalled brake fade. Even in the 80's many large trucks did not have synchronised transmissions, requiring double clutching. Getting a large truck back into gear for down hill engine braking can be very difficult.
     
  14. Gonzalo

    Gonzalo New Member

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  15. Gonzalo

    Gonzalo New Member

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    I have the same problem, every time i brake i hear a metal sound, like there is no brake pads. Does anyone know what this is????

    And there is also a shaking in the pedal, what is that??
     
  16. Fraser

    Fraser New Member

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    Sometimes I hear a brief squeal when we back out of the garage first time in the morning. The sound lasts only until we are at the end of the drive, about 40 feet, and frequently doesn't even last that long. We live in a humid climate, but the car always is inside at night. I lean toward the rust or dust theory.
     
  17. qbee42

    qbee42 My other car is a boat

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    If you live in a humid climate, then it's rust, not dust. Brakes rust very quickly, some more so than others. I lived on the lake shore most of my life, and the Hondas we owned would develop a heavy coating of brake rust over the weekend. Every Monday morning I would hear grinding for the first few stops.

    Tom
     
  18. Fred_H

    Fred_H Misoversimplifier

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    Pressing the accelerator and brake pedals at the same time also activates the friction brakes without having to put the hybrid drive in neutral.

    If accelerator and brakes are pressed too far, power from the engine will suddenly be reduced, so that the brakes can always override the engine. So if you try this, make sure no one is following close behind you.

    Almost every time I drive in the rain, I do this shortly before I arrive, in order to prevent excessive brake rotor rust. Usually I press the brake pedal with my left foot slowly but firmly two or three times for several seconds, while controlling power with my right foot to maintain about twenty-five miles per hour. I try to brake just enough so that the rotors are warm, but not hot to the touch, after I have parked.

    But I don't do this in congested areas because it could impair my reaction time if I would need to brake suddenly.
     
  19. Fraser

    Fraser New Member

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    Yep, I'd tend toward rust. But we also are in a rural area, and the county still hasn't paved all the roads, and there are a lot of undeveloped areas. So some dust can exist in the air because of winds. My thinking on dust as a possibility is that I only hear it first thing out of the garage and only for the two or three seconds I keep the brakes on slightly as I roll back at the door; not a lot of wiggle room for the passenger mirror. I would expect rust to remain on the rotors longer than that.
     
  20. qbee42

    qbee42 My other car is a boat

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    A light coating of rust will be gone in one or two brake applications. Heavy rust is a different story.

    Tom