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Brake failure 2005 Prius

Discussion in 'Gen 2 Prius Main Forum' started by lwinter, May 26, 2006.

  1. auricchio

    auricchio Member

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    <div class='quotetop'>QUOTE(PriuStorm @ Sep 4 2007, 10:50 AM) [snapback]506834[/snapback]</div>
    It's simple. There are lots of expensive parts up front in a Prius that are only available from Toyota.

    Making a repair requires that all mechanical parts be genuine Toyota, unlike most cars where aftermarket engine and accessory parts can be used.

    Result? Front-end damage can total a Prius due to costs. California labor costs might run higher than in other states.

    Also, remember the difference between correlation and causation. Correlation: "All but four US presidents are dead." Do we conclude that becoming president is a death sentence? No, we're just seeing a correlation between the men and the job.

    You can't say that the number of Priuses with front-end damage is caused by a brake failure. Maybe it was tailgating.
     
  2. PriuStorm

    PriuStorm Senior Member

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    <div class='quotetop'>QUOTE(Rick Auricchio @ Sep 4 2007, 04:58 PM) [snapback]506945[/snapback]</div>
    I didn't. I noted that the abundance of them compared to other similarly new models was proportionally higher.

    Rich, what in the front of the Prius makes the parts so expensive? Are all the computers etc. in the front? My last car 5 years ago was totalled from a minor front end collision... the problem there was that the hit exploded the battery all over a multitude of parts and the result was about $8k in damage (the car was only worth $10k). However, in a Prius, the batteries are all located in the rear, right? Even if the damage was $10k... insurance companies wouldn't total a 2007 for that, would they? Wouldn't that be more like 50% of the worth?
     
  3. patsparks

    patsparks An Aussie perspective

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    The HSD inverter is in the front along with all the genuine Toyota panels and the frame rails which are designed to colapse in a gradual manner.
    The bonnet, radiator, A/C condensor are all aluminium and designed to be light weight adding to the cost of production. There are 6 airbags in the higher spec models which if deployed add considerable cost to a repair. The fact the aftermarket manufacturers haven't got into Prius panels means genuine parts are the only option for replacement parts and panels. I don't care what you drive, genuine car parts are always a little more expensive.

    Perhaps Prius owners in a quest to improve milage tailgate more than other drivers?
    Formula 1 cars have more accidents than the average, does that mean they have brake failure?
    Prius has hydraulic brakes like cars from the 50s onwards. They also have regenerative brakes. The hydraulic brakes are as big as any similar weight standard 4 door car and the brake pedal pushrod acts directly on the master cylinder piston. If there was no power to the brakes they will still work, they would require more pressure but they will still work. If there is a problem causing the pedal to drop to the floor it can happen with any modern car, by modern I mean post 1950.
    The Prius has brake assist as standard on all models, that is if you hit the brakes suddenly the automatic brake system will apply more pressure for you, disengage regen braking and the ABS will modulate each wheels brake to bring the car to rest as quickly as possible. This would reduce the number of Prius in accidents compared to lesser cars with no brake assist. Oh all this technology is in the front of the car.

    In an emergency stop sometimes it feels like the brakes have failed even though they are working very well. Oh ABS in some situations can increase stopping distance but you can steer around objects. Use this to avoid a colission.

    Read the thread "Broke my Prius," see how little damage is needed to write off a Prius. Well actually it looks pretty bad but when you think about it the hit was not a real high speed hit, no one was hurt, no airbags went off but the car is a write off.

    Funny thing is, long term members never report this problem only new ones.
     
  4. PriuStorm

    PriuStorm Senior Member

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    Without a doubt, your analysis can be correct as can Rick's. Just as I find it peculiar that there are a proportionally larger amount of newer model Prius's with front end damage, I would find it equally peculiar that what you suggest would be true, that Prius drivers tend to tailgate more... JMHO. I only 'jumped into' this thread to share my observation as a new Prius owner, having read this and the other referenced thread, and having observed the quite high number of salvage newer model Prius's with front end damage available on the resale market in my area and on ebay, so no need to lecture, pls.

    About your claim here:
    <div class='quotetop'>QUOTE(patsparks @ Sep 4 2007, 07:16 PM) [snapback]507009[/snapback]</div>
    what about this from page one:
    <div class='quotetop'>QUOTE(ambrothe @ May 26 2006, 10:52 PM) [snapback]261624[/snapback]</div>
    ambrothe is member 5531 (I'm 30000 something or other), joined April 2005, and has 71 posts... Not trying to argue with you, but to say 'this doesn't happen' or 'this can't happen' is like the 1912 claims of 'The Titanic is unsinkable'... Or does ambrothe's testimony not count since s/he hasn't posted in a while or isn't 'long-term' enough? Anything mechanical can fail.
    :)
     
  5. patsparks

    patsparks An Aussie perspective

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    I'm not saying it can't happen, I'm saying it wouldn't happen in Prius any more often than any other vehicle with ABS and brake assist.
     
  6. lowspeed

    lowspeed Member

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    I just had the weirdest experience.

    I came to a stop and the car actually came to a stop and then suddenly started creeping towards the other car. I thought i was accidentally pressing the gas pedal as well but i wasn't so i started pressing hard on the brake and nothing! i started pumping the brakes and the car stopped. Then i continued my drive as usual without it happening again.

    This totally spooked me. I'm taking the car to the dealer tomorrow.

    No lights came on, nothing unusual. Just weird.

    Car has almost 36K miles 06 model.




    One thing i wish i tried was to use the emergency brake, i just didn't think about it.


    --
     
  7. The Old Man

    The Old Man New Member

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    My red brake lights and ABS (with the exclamation mark) came on today. I decided to drive it to the Toyota dealership and within ten minutes of the lights coming on, the brakes progressively failed and a buzzing sound was coming out of the dashboard. As soon as I drove into the dealership, the brakes almost completely gave out on me. I had to continually pump the brakes to stop! (And I'm very meticulous about my Prius...all of my cars, actually). Thank God this didn't happen while I was on the freeway and/or driving at a high rate of speed. Fortunately, I was also close to the dealership. I brought it to the attention of one of the service representatives (I do have to say lacked customer service skills) and was told that it would be necessary to reprogram the ABS system. Just like that! It seems to be that Toyota needs to re-call this and get all the Prii off the roads and get these ABS systems modified/fixed before it really hurts someone. THIS IS ALL DOCUMENTED NOW so if a Toyota Prius does get into a traffic collision and injures someone (minor to fatal) and it is determined that there were faulty brakes and/or a faulty ABS system, Toyota's reputation and the Prius' reputation will be drastically affected. TOYOTA....ARE YOU GUYS LISTENING/READING????? Better do something about this!

    I have an 05 Prius with approximately 36,000+ miles...fortunately, I purchased the extended warranty so everything was fully covered. The service rep told me that my warranty would pay for a rental car and then when I came back to pick up my Prius (same day), Toyota tried to charge me for the rental car. Go figure!
     
  8. lowspeed

    lowspeed Member

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    They are not going to do a thing unless enough people submit complaints to the NHTSA:

    http://www-odi.nhtsa.dot.gov/ivoq/


    Not that i think we had the same problem, but brakes are not something to mess with. My heart fell to the ground when the car started creeping forward.




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    <div class='quotetop'>QUOTE(lowspeed @ Oct 18 2007, 08:30 AM) [snapback]527257[/snapback]</div>

    Holly s**t i did a search on that site and there's a description exactly like mine (well almost, i actually came to a stop then started creeping): (its under the service brakes, hydraulic: antilock category.

    "I'VE A 2006 TOYOTA PRIUS. TRAFFIC STOPPED FOR A RED LIGHT AND I WAS BEHIND A CEMENT TRUCK. I SLOWED TO A COMPLETE STOP ABOUT 5 FT. BEHIND THIS TRUCK. ALL OF SUDDEN I NOTICED MY CAR STARTED MOVING FORWARD WITH MY FOOT STILL ON THE BRAKE. I STOOD ON MY BRAKE AND COULDN'T STOP THE PRIUS. IT CONTACTED THE CEMENT TRUCK CAUSING A DENT ON THE RIGHT SIDE OF THE HOOD AND A CRACK WINDSHIELD. *NM THE CONSUMER STATED AS TRAFFIC BEGAN TO STOP FOR A RED LIGHT, HE BEGAN BRAKING FROM ABOUT 25 MPH WHICH SEEMED NORMAL. HE CONTINUED TO GRADUALLY SLOW THE VEHICLE DOWN AT A DISTANCE OF ABOUT 5 TO 10 FEET, THE CONSUMER ESTIMATED HIS SPEED WAS ABOUT 3-5 MPH. THE BRAKES LOCKED UP AND FAILED TO STOP THE VEHICLE, CONSEQUENTLY THE CONSUMER REAR ENDED ANOTHER VEHICLE. THE BRAKES FELT HARD, NOT SPONGY AND NOT PULSATING. THE VEHICLE LOST ALL BRAKING COMPLETELY. UPDATED 01/10/07.*JB"
     
  9. auricchio

    auricchio Member

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    <div class='quotetop'>QUOTE(PriuStorm @ Sep 4 2007, 04:14 PM) [snapback]506968[/snapback]</div>
    First, I apologize for ignoring this thread for so long.

    Second, I should have more correctly said "One cannot say brake failure caused.." I didn't mean to imply you actually said that. You were, however, implying a cause.

    Another possible cause of Prius front-end damage? Prius drivers looking at the screen, thinking about saving fuel, demonstrating features to passengers, etc. The car presents many distractions to a new driver.
     
  10. lowspeed

    lowspeed Member

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    So here's an update...

    The dealer didn't find anything wrong with the brakes ("suprising").

    I didn't think they would after 36,000 miles it only happend once (actually if you count out our previous prius it would be 50K+ miles) ... how can someone duplicate something like that.

    But i did put a complaint with the NHTSA.


    Hopefully it doesn't happen again.



    --
     
  11. Mawcawfee

    Mawcawfee Prius-less (for now)

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    Very interesting thread (and troubling). Perhaps I can be of some assistance in an indirect way, based on my own driving experiences. I have a '99 Chevy Prizm (a.k.a. Toyota Corolla) with just ABS (no traction or stability control). About a 18 months ago, on multiple occasions when coming to a stop, I frequently encountered braking problems seemingly identical to some reported in this thread:

    Problem #1: Coming to slow, gradual stop on smooth surface on dry, sunny day. Plenty of stopping distance. ABS kicked in way too early and stayed on. Brake pedal went to the floor and I held it there. Car kept rolling forward at slow speed (in one case right through a stop sign) for no apparent reason.

    Problem #2: Coming to a quicker than normal stop on a less than smooth surface on dry, sunny day. ABS kicked in and stayed on. Brake pedal stayed firm but pulsing hard from ABS. Car took a lot a longer to stop than normal.

    I was certain my brake system had a problem. I had my mechanic test drive the car and inspect the brakes and he said everything was great. I knew it was not suspension related because it had been completely upgraded to a much firmer setup about a year earlier. The suspension was definitely doing its best to keep the tires in contact with the road. Anyway, I solved the problems after a week or so of trial and error. There were two issues:

    Solution #1: My tire pressure was not high enough. All four tires were at 29 psi. Maintaining 35 psi solved the problem on uneven surfaces, as my tires were no longer bouncing, in spite of my suspension's best efforts to prevent it. I did my testing at a nearby intersection with a very bad stretch of washboard asphalt as I roll up to the stop sign. At higher tire psi, ABS still kicked in on occasion (as it should when braking hard on a washboard surface), but the car no longer took excessively long to stop no matter how often I tried.

    Solution #2: The tires! The car had a set of high-end 80K Michelin all-season tires that worked great for the first 40K miles or so. But after that, the tires lost all their grip. Mind you, I drive like grandpa, and these tires still had 2/3rds of their tread left. I was able to figure out the tires were the culprit by repeatedly testing the car's handling and braking on an empty street in an industrial park. As I would keep approaching a stop sign at about 25mph, I would brake normally to come to a slow stop. But I noticed that even the slightest amount of sand on the road made the ABS kick in and the car take a ridiculously long distance to stop. Turning the wheel while I was slowing down proved to me it was the tires, since the car kept sliding straight forward even with the steering wheel turned one complete revolution from center. So, I was off to the tire shop to get a new set of Yokohama AVIDs installed. With that done, back to testing the tires again. With the new tires in place at 35 psi, no problems whatsoever on any road surface.

    I have had the Yokohamas for more than a year now and have never encountered another braking issue in any conditions, rain and snow included. Worth emphasizing is that nothing was done to the brakes, yet the braking problems completely disappeared per my above solutions. So, here are the important questions. For everyone encountering similar braking problems with a Prius, who has the OEM Goodyear Integrity tires? What is your psi? Given that these tires are low rolling resistance by design, I would not be surprised if your OEM tires have no grip left and the car is just skating forward as you try to brake, just like my car did. Simply replacing your tires with something like Goodyear Tripletreds might solve the problem(s).

    One last observation. A Prius weighs 500lbs more than my Prizm (3,000lbs vs. 2,500lbs). If your tires are the problem (lack of grip), it's going to take a lot longer to stop that much more mass.
     
  12. richardGear

    richardGear New Member

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    Brake Failure, This happened to me today 8/5/08. I purchased this 2004 prius 2 weeks ago(90,00o miles), and ive only had problems up till now. I was driving at about 25 MPH, when all of the sudden the ABS warning light went off, and the brake light turned on(and a buzzer was heard). I pressed the break pedal hard in order to get the car to break. It felt just like when a conventional car looses its breaks. Thanks God I was only 1 mile from the Toyota dealer. I had a sceduled evaporator replacement ($450)sceduled for tomorrow so I decided to leave the car at the dealer (this is what the manual says to do when both warnings go off).

    Does anyone now what the dealer is charging to pertend to know what the problem is.

    After reading all these post and I think back to what actually happened, I remember that a had just gone over a pot hole when this happened.

    Please keep posting, we have to get the word out about this flaw as I understand that in 2016 all cars will be Hybrid.

    Thanks
    [​IMG] [​IMG]
     
  13. sorka

    sorka Active Member

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    Wish I'd seen this thread earlier. I had no idea that so many Prius's were having brake failures. I hope everyone is reporting them to the nhtsa.

    I'm having serious second thoughts and may cancel my order. My wife and 4 year old daughter would be the primary passengers in this car and I cannot risk the brakes failing and causing a fatal or serious accident with either of them in the car.

    Clearly not enough have reported this to the NHTSA as this thread is several years old already.

    As to those that say the Prius has a hydraulic braking system just like any other car, keep this in mind:

    The prius's anti lock braking modulator, when software determines, can open up a pressure relief actuator which releases braking pressure. If the actuator opens up all the way, you could push the brake pedal all the way to floor and it would make no difference.

    Additionally, vehicles with stability control programs can also release the actuators to un-brake one or more wheels. In many cars, when the stability control program is actively doing something, the ABS light lights up, so a lit ABS light could be a confused ABS response or a confused stability (VSC) control program response.

    I think I'll just keep having my wife drive her 5.7 Hemi Durango for the time being and wait. I don't want to risk my child's life.
     
  14. Bobwho

    Bobwho New Member

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    I have a theory about this brake failure:

    1 These cars are driven gently.
    2 No one, repeat no one remembers how the rear brake adjusters work.
    3 Failing to utilize the automatic adjusters leaves the rear brake cylinders extend to the point that they vent brake fluid and have no effective braking action.
    4 Brake failure ensues.

    This is so typical of an engineering project that it just screams out to me. Everyone forgets how things work and the product fails to perform as expected.

    Therefore:
    LEARN HOW THE REAR BRAKE ADJUSTERS WORK! Stomp the brakes dozens, to hundreds of times repeatedly as necessary while traveling backwards in a safe area clear of all obstacles and pedestrians.


    IF you fail to actuate the the self adjusters then the brakes will fail eventually.
     
  15. Patrick Wong

    Patrick Wong DIY Enthusiast

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  16. auricchio

    auricchio Member

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    I thought the rear brake adjuster was part of the parking-brake system, not the usual brake-in-reverse mechanism.
     
  17. sorka

    sorka Active Member

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    Just spent an hour reading through dozens of complaints on the nhtsa.gov website. In order to find them, you have to select the year, make, model, and component. There a number different types of braking components, so you have to select each one one at a time to run the reports. In all, there are dozens of reports almost all identical describing same thing. The thing is that for every one that is reported on this site, there are dozens more that aren't. The interesting thing is that in about half the cases, it results in a front end collision.

    I think I'm going to agree that the reason there are so many front end collision prius's out there with salvage titles is due to this particular failure.

    So far, there's not a single report of any braking failure on the 2008. I know we're only half way through the year, but since most other years have a dozen or so reports, you'd expect at least some on the 2008. I wonder if they quietly fixed the ABS/VSC software without telling anyone?
     
  18. hobbit

    hobbit Senior Member

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    Sorka, what the F are you talking about? You clearly don't
    know how the prius braking system works, or how the self adjusting
    stuff for the rear wheels works, although it's been thoroughly
    documented if you'd care to go off and research it a little bit.
    The little "sag" one gets at the 8mph transition is also well
    known, but it's not something you can class as "this particular
    failure" since it's not a failure, it's a quirk, and doesn't
    diminish overall braking power at all.
    .
    Knock it off with the disinformation until you're ready for a
    precise point description of this supposed problem.
    .
    _H*
     
  19. sorka

    sorka Active Member

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    Wow! 2000 Posts and you clearly don't know anything about anything.

    Go read the NHTSA reports. In all cases, the brake pedal went ALL THE WAY TO THE FLOOR AND THE CAR DID NOT STOP or even start to slow down!

    That is not a quirk. It's a complete failure and it has caused dozens of accidents that have been reported to the NHTSA and certainly hundreds more that haven't been reported.

    You can try to spout anything you want, but facts are facts and nothing you can say will change them.

    What is the cause of these COMPLETE FAILURES? Who knows, but I'll bet that it is not a mechanical or electronic failure. If it were a simple electronic failure, the hydraulic system wouldn't have it's pressure released by the ABS solenoids which is the only way you can put the brake all the way to the floor and have the brakes failure in the absence of a mechanical failure. If the ABS system thought it needed to unlock the brakes or the VSC, which can brake or unbrake wheels individually, got confused from sensor resulting in opening up the solenoids.
     
  20. Patrick Wong

    Patrick Wong DIY Enthusiast

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    In my prior post #75, I provided a link to a message string that provides one possible reason for the brake failures: DTC C1247, Malfunction in Stroke Sensor.