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Brakes click when going in reverse

Discussion in 'Prime Care, Maintenance and Troubleshooting' started by HypersonicPrime, Jun 14, 2018.

  1. HypersonicPrime

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    Hey everyone. I've got about 9000 miles on my Prius Prime now and I'm still very pleased. I did notice recently that when I'm going in reverse if I step on the brakes I hear a click (I think as the friction brake pads touch the rotors). The quicker I step on the brakes the louder the click. Because the car is so quiet, it seems loud. If it's a slow application the click is more faint. The brakes work fine and all. This may have always been the case and I didn't notice it. This is probably not an issue, but I want to know if others hear this too. I do not hear any clicks when going forward and the car transitions from regenerative braking to friction braking or if I brake quickly (total friction braking), but the circumstances are different so the comparison may not be appropriate.
     
  2. ChapmanF

    ChapmanF Senior Member

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    The pads are free to wiggle slightly in the caliper mount that supports them by their 'ears'. Usually, they are all the way forward, because that's the way they get shoved by wheel rotation when you brake moving forward, which is the usual case. That's also the direction the springy 'fitting kit' pieces hold them, so your forward braking is normally clickless.

    So they have a mm or so of room to slip the other direction when you brake in reverse, before they bonk the other side of the mounting bracket with a click sound.

    The pads have a couple layers of shims behind them, with grease between the shims, just to make it easy for them to slide around, so a nice distinct click when you brake in reverse tells you they are sliding around nicely, and isn't a bad sign at all.

    -Chap
     
  3. bisco

    bisco cookie crumbler

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    seems odd to me, but one mans click is another mans tap.
     
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  4. burnout8488

    burnout8488 Member

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    It is normal.
     
  5. ChapmanF

    ChapmanF Senior Member

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    If mine ever stopped clicking when I reverse, I'd probably make a mental note to get out the jack and find out why. Not urgently, but when convenient.

    -Chap
     
  6. padroo

    padroo Senior Member

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    I guess I will have to pay more attention. My wife has good hearing I will ask her.
     
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  7. HypersonicPrime

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    After listening to it more, i believe @ChapmanF is correct. It's mainly the first application of the brakes in reverse. After that I don't really hear it.
     
  8. jaymac

    jaymac membore

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    My 2013 v5 clicks only in reverse. I think the sound is only coming from the right front wheel.
    My 2012 gen3 liftback never did this.
    I’m going to see if my preferred dealer, Kendall in Eugene , can fix this for me.
    If there is play in the pads there must be a mechanism to install shims.
     
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  9. ChapmanF

    ChapmanF Senior Member

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    Wouldn't be any sense in taking all the play out. Given high heat and differing rates of thermal expansion, binding would be sure to result. The brakes are designed as they are so the pad ears easily slide in the mounting bracket grooves, and the fitting-kit pieces keep them nudged in the forward-braking direction, so there is normally no click in the usual case.