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Rear disk premature wear

Discussion in 'Gen 3 Prius Care, Maintenance & Troubleshooting' started by CivicQc, Apr 22, 2012.

  1. CivicQc

    CivicQc The world needs more prius

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    I searched this site without finding an answer to this.

    When I changed my tires last week, I noticed the rear disks had a groove in it. That seems to be a sign of wear, but having never checked that before, I do not know whether that is new or not. Note that my front disk are totally fine - nearly as new.

    I was expecting the Prius brakes to last a for a long time, because of regen braking... Moreover, I was expecting the front brakes to wear more quickly, not the rear ones.

    Did any of you notice an unexpected wear of the rear disks w/r to the front ones? Is that normal, or could it be that my rear brakes are not adjusted properly?
     
  2. spiderman

    spiderman wretched

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    Depends on how deep the grove. If you run you finger nail over it, does it get snagged? Minor groves are normal. I would suspect all you need it to have your rotors turned to remove the glaze. Some shops do that for free.
     
  3. El Dobro

    El Dobro A Member

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    Did you look through the hole in the rear calipers to see how much of the pads are left?
     
  4. GrumpyCabbie

    GrumpyCabbie Senior Member

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    Depends on your mileage as well.

    If you have 2,000 miles and it's a deep groove then it's a problem.

    If you have 86,000 miles and it's a minor groove then it's not a problem.

    If you don't do many miles and leave the car outside then the rear brakes do seem to rust up easier. There are ways to remove this rust, such as, after making sure there's nobody behind you, press on the brakes quite hard and bring yourself to a quick, but safe stop. This should burn the rust off - just be careful!
     
  5. CivicQc

    CivicQc The world needs more prius

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    Thank you all - I will check the pads and disks again this evening and come back to you.
     
  6. css28

    css28 Senior Member

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    Rear disc brakes are more prone to get debris (sand, gravel, etc.) trapped between the pad and rotor.
     
  7. JayR

    JayR Junior Member

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  8. JayR

    JayR Junior Member

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    I concur with CivicQc. I've been driving my 2012 Prius for 35,000 Kms and I also noticed that the rear brakes are wearing faster than the front. What's the point of regen braking (from the front/traction wheels) when the back brakes are going against regen with friction braking. Maybe it has something to do with security i(n case of an emergency stop) or is it an unbalanced adjustment between front and back brakes ? I'll bounce this off the dealer to see what they come up with.
     
  9. Mendel Leisk

    Mendel Leisk Senior Member

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    Could also be due to forgetting the parking brake release.
     
  10. GregP507

    GregP507 Senior Member

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    I've seen mud lodged between brake-pad and rotor causing rapid degradation of the brakes. Not something I've experienced, but a friend with a similar '06 Dodge Ram had them fail at less than 2 years of use. Mine actually went over 100k before I needed the pads replaced.

    I'm also wondering about the expected lifespan of the Prius brakes. I haven't found any good information so far. I know the brakes engage at low speeds, because I can feel the pads skipping on the rotors at a traffic light. But my question is how much do they actually wear during normal driving? I've retrained myself not to downshift to "save the brakes" anymore, using the brakes for regeneration instead, but are they good quality brakes which should last forever, or are they a cheapened-up version, designed for occasional use?

    I'd like to know how much wear to expect from my brakes. Thanks in advance.
     
    #10 GregP507, Jul 7, 2014
    Last edited: Jul 7, 2014
  11. GregP507

    GregP507 Senior Member

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    It's hard to ignore the warning light and beeper when you drive with the parking brake on. I'm not sure why there's no lockout, which prevents putting the car in "drive" when you try to go with the parking brake on, but it does happen however. I did it myself for a short distance. There is certainly a lockout preventing using the VTR function on the display screen, which is disabled unless you have the parking brake engaged.

    Perhaps it better serves the interests of Toyota to prevent distracted driving accidents, than it does to help avoid replacing brake-pads which are worn out due to the driver's own carelessness.