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Brake 'fix' failing?

Discussion in 'Gen 3 Prius Care, Maintenance & Troubleshooting' started by pinky, Aug 24, 2010.

  1. pinky

    pinky New Member

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    I checked the previous 6 screens of threads and saw nothing on this so forgive me if this is out here already.

    I have been noticing that when I brake over rough conditions it feels almost like the brakes are back to their old 'pre-recall' status.

    Is that possible? Has anyone else still felt the loss of braking on rough road after getting their Prius 'fixed'? It's not as bad as it used to be but does feel like it just stops braking on rough road...

    Should I take it to another dealer and have it 'fixed' again?

    Thanks!
     
  2. LulzChicken

    LulzChicken Prius Enthusiast

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    I do believe it is still possible, because all the update did was shorten the amount of time it takes for the brakes to switch over from engine breaking to hydraulic breaks. I believe.. I may be wrong. I still experience it. For example, we are having construction done on a road here - when I break over a drop off of about 2-3 inches, my breaks stop working for 1 second and I have to push harder - sometimes not even giving me any more "stopping" force. I wouldn't bother taking it in again, they'll turn you away and say everything is up to par.
     
  3. viprius

    viprius Junior Member

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    Accept the fact that brake fix really did nothing more than appease the masses! It's no big deal for me and I can live with it!
     
  4. qbee42

    qbee42 My other car is a boat

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    Time to go back and read those 6 screens of threads. This issue has been addressed in detail.

    The short answer is that your Prius still does this over rough roads. Other cars with ABS also do it, although the regenerative braking system on the Prius makes it more obvious. There isn't anything to fix: your Prius is working as designed.

    Tom
     
  5. fjpod

    fjpod Member

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    For me it seems like the opposite. My brake fix seems to have gotten better. About a month after I first got it, I posted that the fix seemed to reduce the occurence by about 50% and when it did happen, it felt about half as severe. Now, about three months later...well I haven't felt it for about a month. Before the fix, I would feel it 3-4 times per week.

    BTW, during the three months since the fix, my average mpg has gone up. I attribute this though, to the warm weather without too much AC.
     
  6. pinky

    pinky New Member

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    I was just amazed, and somewhat unsettled that it keeps happening. The incident was when I was going less than 10MPH, probably way less, and the road (if you can call it that) had some severe close together patches that were rather rough and I was trying to stop with a car that was just on the far edge of the rough and for an instant, the car acted like it wasn't going to stop! Living in Michigan, Tom, I'm sure you drive our bad roads. It pissed me off that I almost ended up running into the back of the car in front of me, going less than 10MPH, because my car wouldn't stop.

    On the mpg, mine went down but now with the summer I seem to be getting better mileage than before. Go figure. Maybe I'm just driving better... Mpg is such a deceiving quantity. If I drive in the hills, it sucks. Driving around flat home roads, it soars. Currently averaging 47...
     
  7. qbee42

    qbee42 My other car is a boat

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    This is what happens when you try to brake on washboard surfaces. It's not just the Prius, but with all wheeled vehicles. The exact response to any given washboard surface will depend on the characteristics of the tires and suspension, but at the proper speed any car will effectively turn into a hovercraft, losing the ability to brake and/or steer.

    I used to see this effect in my old Jeep. It had big tires and heavy suspension. The brake system was all manual, with no thought of ABS. It would do exactly the same thing: when you hit a gnarly patch of road the suspension would resonate. Braking was ineffective and steering greatly reduced. More than once I came close to drifting off the outside of a curve on a bumpy dirt road. Of course I was driving like an idiot, but that's another story.

    Someplace along the line people have developed the expectation that cars will steer and brake regardless of the conditions. People have even posted complaints relating to braking when on ice. If the tires don't have a grip on the road, you aren't going to be able to steer or brake. It's that simple.

    Tom
     
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  8. tumbleweed

    tumbleweed Senior Member

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    I did experience this braking anomaly a few times but decided not to have the "brake fix recall" done.

    Now my brakes are getting better and better, I think I found the answer, just wait and it fixes itself. Unfortunately those of you who had the recall done can't go back. :)

    I may have one of the few Gen3 Prius left with "proper feeling" hybrid brakes.
     
  9. teeasal

    teeasal New Member

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    I bought the Prius AFTER the brake fix so I assume that the fix-patch was installed before I took possession of the car.

    I drive on really rough roads everyday. Water seeps into cracks on the road surface and got frozen in winter. the Ice expands the cracks and eventually they become huge pot-holes. The city is patching them up every year, making the roads look like...what else, a patch work!

    Yet no such occurance of loosing brake feeling for me on these "patches".

    However, on a completely smooth (city completely repaved) road, in the summer, where the new pavement joins the old pavement, just about 20 yards from a red light, a huge bump developed across the whole lane. I assume that it was the summer heat that expands the pavement which pushed against the old settled pavement creating a bulge.

    It is at this bulge that I experienced that lost-of-brake feeling. At first I did not know and did not expect the existance of the bulge, ran through it while braking before the red light, felt the front wheels air-born (just a feeling) for a split second, and the car seemed to be jerking forward at that same moment, thus lost-of-brake feeling.

    I guess that the reduced friction between the tires and the road triggerred the ABS to disengage the mechanical brakes momentarily to "unlock" the wheels. That's what the Anti-Locking-Brake-System supposed to do. It is working as designed but it gives the dirver a lost-of-brake feeling for a split second.

    I think this problem occurs to all cars with ABS, not just to Prii.
     
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