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Prius sometimes lurches forward when I apply the brakes.

Discussion in 'Gen 3 Prius Main Forum' started by GreenTree11, Jul 29, 2011.

  1. kithmo

    kithmo Couch Potato

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    That explains why I can't feel any difference with the Prius compared to previous cars, except when going over a manhole cover with one front wheel whilst presumably on regen braking, the car seems to lurch forward.
    When one front wheel lets go I assume the car suddenly has half as much brake force because the rear wheels are not assisting, or do I loose all the regen braking when one wheel lets go due to the differential ?
    On a car with normal brakes you would only loose a quarter of the brake force if one wheel lets go.
    Other than that it feels just like normal brakes, no transition, I can't usually tell if I'm on regen or pads unless I look at the HSI.
     
  2. qbee42

    qbee42 My other car is a boat

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    You lose all of the regenerative braking due to the differential.

    Tom
     
  3. macman408

    macman408 Electron Guidance Counselor

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    I wouldn't think it's from the differential, though, is it? There are a variety of reasons that it might do this - protecting the electrical systems from over-voltage/over-current, traction or stability control (otherwise the car would start turning due to reduced braking ability on one side of the car), a general design decision to switch to friction brakes for better control when a non-uniform ground surface is detected, etc.
     
  4. civicdriver06

    civicdriver06 Active Member

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    I don´t even have a hybrid,i drive a normal Honda Civic but if i go over a manhole cover i get the exact same feeling !
    You have that on every car with ABS-System !
    Its absolultly normal and has nothing to do wether ist a hybrid or not !
    In some cars you feel it a little bit more and in others you feel it less,but it´s no saftey issue its normal !
     
  5. oldasdust

    oldasdust Member

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    Mine has done it a couple times on washboard pavement the first time was the worst. A ka ka moment right in the drivers seat.
     
  6. qbee42

    qbee42 My other car is a boat

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    Yes, it's from the differential. Think for a minute how regenerative braking works: MG2 is attached to the drive shaft, which goes through the differential to each front wheel. To regenerate, MG2 applies drag to the drive shaft, applying drag to both front wheels as long as both wheels remain firmly gripping the road. As soon as one wheel loses traction, the other wheel spins it instead of spinning MG2.

    Tom
     
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  7. kithmo

    kithmo Couch Potato

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    That's what I thought:nod: