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prius regen brake pedal feel

Discussion in 'Gen 3 Prius Main Forum' started by camry25, Aug 7, 2012.

  1. camry25

    camry25 Junior Member

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    I tested prius 1 or 2 years ago and pedal feel (during emergency braking) was terrible. I read it switches on/off to regular friction brakes. Is this what its doing?
     
  2. jdcollins5

    jdcollins5 Senior Member

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    The Prius under normal braking uses the electric motors for regen braking, while charging the HV battery, down to about 7 mph and then switches to friction brakes for final stopping and holding. If you hit a bump or a slick spot while in regen and a wheel slips it will switch to friction braking.

    In an emergency braking situation it goes straight to friction braking, bypassing the regen.

    Why do you say that during your test drive the pedal feel was terrible? Mine feels like every other car I have ever driven.
     
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  3. camry25

    camry25 Junior Member

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    This was at I don't know 15mph so maybe it was using regen not friction braking
     
  4. gmcneil05

    gmcneil05 Member

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    The Prius has terrible peddle feel... For road racing. With abs, brake force distribution, and stability control you don't need feel. Just stomp on them and let the car do the rest in a emergency. The strange feel will go away once you get use to it.
     
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  5. El Gato

    El Gato Junior Member

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    I have experienced this and for the 3 years now I've had my Prius still am not used to it. It is a momentary feeling of loss of control when I brake while hitting a bump and feeling like my brakes give out. Car feels like it moves forward in that split second that it occurs. Not a fun feeling.
     
  6. Michael Cline

    Michael Cline Junior Member

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    I have a 2010 Prius with the original (not yet recall updated) breaking firmware, and have also driven a 2013 regular and 2013 PIP. One thing very noticeable on my 2010 Prius but barely detectable on the newer Priuses is while decelerating at about 75% regenerative braking power, as the vehicle slows below 7mpg, there is a very noticeable transition from regenerative braking to friction breaks with accompanying brief reduction in breaking force. Can someone else with a 2010 model confirm if this is normal? Can anyone with a 2010 model which had the recall remember if the recall reduced this effect? (I'm confident the recall update will improve driving over a bump performance, which I'm quite familiar with.) Does the recall cause the friction breaks to kick-in at a slightly higher ratio when breaking near the limit of regenerative breaking to lessen the transition effect, at the expense of less regeneration in some circumstances? Speculation is welcomed, but first hand experience is preferred. Thanks!
     
  7. fuzzy1

    fuzzy1 Senior Member

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    I had a 2010 for three years, and this 7 mph transition was often quite noticeable. Many other readers here also reported it. I think part of the issue was trying to get the braking force for each mode matched, for a given pedal pressure. The match was clearly not perfect, and may be a moving target as the brake pads wear. While the recall may have reduced this (I don't recall how much), it definitely did not eliminate it.

    It does seem less noticeable on my 2012. Sorry, can't answer the rest.
     
  8. xliderider

    xliderider Senior Member

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    Breaking = bad. Braking = good. ;)

    Our 2011 has this transition you refer to. If I don't ease up on the brake pedal just before the car comes to a stop, it will stop a bit abruptly.

    SCH-I535
     
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  9. tumbleweed

    tumbleweed Senior Member

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    I too have a 2010 (build date July 2009) with the original brake firmware. I have not noticed the distinct transition from regen to friction braking, mine feels more like the newer Prius you describe. Braking is very smooth and you have to be paying attention to even notice when it switches from regen to friction at approximately 7 mph. In fact that is one of the reasons I did not have the firmware upgraded, I didn't want to change the way the brakes feel.

    I will have it upgraded for the next owner before I sell the car. I do have the "OH MY GOD" moment occasionally when braking on slippery surfaces but it rarely happens and I am used to it by now.
     
  10. ursle

    ursle Gas miser

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    My gen 3 is much less noticeable (brake gremlins) then my gen 2
     
  11. Jonny Zero

    Jonny Zero Giggidy

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    My Prius' brakes pedal is made from sponges it feels like. Come to think about it, so are the suspension members. :p
     
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  12. WE0H

    WE0H Senior Member

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    Have you driven a Plus Perf yet? Pretty decent suspension for a stock car ;-)

    Me thinks the brake assist feature is what people feel at slower speeds while braking normal. Toyota's seem more wicked than some other brands.

    Mike

    Mobile on my SGH-i717
     
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  13. Metalman

    Metalman Member

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    I have a 2010 Prius and I feel the brakes get more "touchy" around 7 mph. Certainly no less braking is noticed. But I've never braked in an emergency or with much vigor. Looking and thinking ahead helps.
     
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  14. tumbleweed

    tumbleweed Senior Member

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    I agree, looking as far ahead as you can is much safer and does prevent the need for "panic stops" most of the time. But situations will develop that we simply didn't or couldn't notice in time, when that happens it's good to know ahead of time how the brakes act in an emergency stop.

    A couple of times a year I find deserted stretch of highway and do a practice emergency stop or two from 60 or 70 mph. It tells me that the brakes really do work OK and reminds me what it feels and sounds like.
     
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