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Embarrasing brake problem.. normal?

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by Prius904, Oct 9, 2013.

  1. Prius904

    Prius904 Junior Member

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    So several times now in the last couple months during rainy weather, as I come to a complete stop, my car's brakes react rather violently, embarrassing me in front of other drivers. I am aware that the Prius has a sensitive braking system but this seems a bit much. The best way to describe it is in the final moments of stopping, when the car is 5 mph or so, it rapidly engages/disengages the brakes. Much like anti locking brakes do in a icy environment. The thing is, although its rainy and the road is wet, the road is not slippery. I understand the brake pads are wet. It seems unsafe because my planned point of complete stoppage is extended by a foot or so, which could result in a fender bender if I am not careful. I definitely don't feel comfortable letting anyone drive this car in wet weather lol.

    An immediate answer would be to go get my brakes checked, but I had the entire car checked when I bought it, and nothing was noticed with the brakes.. the first incident was shortly after the purchase and I dismissed it because I had read brakes/steering takes getting used to.
     
  2. jgilliam1955

    jgilliam1955 Sometime your just gotta cry! 2013 Prius 4.

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    Get the brakes checked out again.

    SCH-I535 ? 2
     
  3. edthefox5

    edthefox5 Senior Member

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    Extremely common compliant. Its because the hydraulic brakes are not used much as alot of the braking energy is done by regen. Not alot of severe clamping of the brake pads against the brake rotor resulting in a build up of rust on the rotor making them especially grabby when damp out. This is exacerbated by not garaging the car.Without regen assistance the brakes are quite poor on this car.

    Easy long term help is to routinely clean the rotors by putting the car in neutral (which removes all regen assistance) and at speed apply the brakes firmly like you have to stop soon 1/2 mile away. First time you do this make sure no car in front or behind you as you will be startled how poor the brakes are without regen.

    Alot of us routinely do this. My rotors don't look to bad. Somewhat shiny. I'm so used to it its like second nature to slap it in neutral and just come to my next stop. Really helps.

    Yours may be too far gone rusted. Get a flashlight and look between the front wheel spokes.
     
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  4. xliderider

    xliderider Senior Member

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    Agree, get it checked, it's a safety issue.

    It may be one of the wheel speed sensors is bad, triggering the ABS. No dash alerts illuminate when this occurs?
     
  5. desmondlee

    desmondlee Member

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    did you go over a little bump or anything? My brakes would do that over a little bump when my foot was on the brakes.
     
  6. vskid3

    vskid3 Active Member

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    Mine did the same during and even after a good rainstorm a month ago. I did the braking in neutral like edthefox5 described and the problem went away.
     
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  7. Prius904

    Prius904 Junior Member

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    No gauge lights come on.. So odd that the car does this. And it is sounding like its common. Seems like a major liability for Toyota not to issue a safety recall. I will have to look into doing what yall say to do with car in neutral.. I have never put it in neutral while driving yet. Im assuming just let off gas and push the shifter to the left and let go? And then brake at what speed? At 45 mph and push brake down as far as it will allow until complete stop? What a very odd situation this is...

    thanks for the replies so far everyone!
     
  8. vskid3

    vskid3 Active Member

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    I've driven other cars that do pretty much the same thing, you just notice it more in the Prius because of the switch between regen and friction brakes.
    When I cleaned mine, I got up to 35MPH, shifted to N, and pressed the brake with moderate pressure until about 25MPH. It really shouldn't take much to clean them unless they're really bad.
     
  9. Jon Hagen

    Jon Hagen Active Member

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    Remember !! You must hold the lever in the N position for 3 seconds for it to shift to N. Watch the dash gear indicator to make sure it indicates N before attempting the rotor cleaning.
     
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  10. alekska

    alekska Active Member

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    Somehow on my 2005 Prius brakes are not "poor". They are very adequate even in neutral. And yes, grubbiness at 5 mph is due to rust on rotors from parking outside in rain.
    Alex
     
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  11. kenoarto

    kenoarto Senior Member

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    Another thumbs up vote for the cleaning the brakes a few times via putting in neutral trick. Works every time.
     
  12. dorunron

    dorunron Senior Member

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    Yup, I agree also. If it bothers you do the cleaning thing. After awhile you will get accustomed to it, and expect it. It is exacerbated if the Prius sits for several days between driving and also when the humidity is high or just after the dew has fallen, rain etc.

    Honestly, I don't think it is a safety issue. Normally, the car tends to stop a little quicker when this happens. It just startles one who is not used to it.

    You can clean the rotors as pointed out above, but you will have to do it more than once if you are in a humid or wet area. Remember you can't just slap it into neutral. You have to hold the lever in N for at least three seconds for the transaxle to shift to the N position.
     
  13. edthefox5

    edthefox5 Senior Member

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    Besides its a very good thing to know how to put the car in neutral in an instant to prevent a run away car.
    Its second nature in all my cars. My other non hybrid cars I automatically put the car in neutral at a stoplight.
    Easier on the trans.
    In my Prius I do it quite often approaching a stop if the battery is already in green and to clean the brakes.
    2 birds with one stone. My rotors look pretty good but still some base rust under the shine. Not anything like a normal car with super shiny rotors. I would imagine if the OP does as I requested he will find his rotors are really rusted and may need to be replaced.

    This is one of the most common complaints here at PC that and the dead little 12 volter.
     
  14. The Electric Me

    The Electric Me Go Speed Go!

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    I live in the Northwest, and we get lots of rain.
    So I can tell you with confidence that what you are experiencing isn't the norm.

    There is a rather hotly debated and high profile reaction of the brakes that can happen under very specific conditions, that creates for some people the feeling of the brakes lunging. But what you are describing doesn't sound to me like that situation.

    I've have used the brakes in rain conditions on pavement, manhole covers, slick spots...and never have they reacted in the manner you are describing. If this is happening you need to get them checked out again.
     
  15. edthefox5

    edthefox5 Senior Member

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    And what brand of tires are you running. Hope to god you don't have a set of GoodYear Integrities on the car.
     
  16. edthefox5

    edthefox5 Senior Member

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  17. xliderider

    xliderider Senior Member

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    I also thought putting the transmission in neutral was better as far as wear and tear until I read that it puts wear on the shift components.

    I always shifted to neutral at stop lights in our Quest van. We started having transmission trouble and decided to get another vehicle rather than deal with potentially expensive diagnosis and repair of transmission problems.
     
  18. Britprius

    Britprius Senior Member

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    The difference in the Prius is it does not shift gears at all, even for reverse.
    The various modes, neutral, drive, and reverse are all mechanically the same. The only exception is park where the transmission is locked by a pawl mechanism. The rest of the transmission still remains the same as in the other three modes.

    John (Britprius)
     
  19. xliderider

    xliderider Senior Member

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    Thanks, I understand that. I was replying to the comment that he is doing it on his non-hybrid cars. :)
     
  20. Britprius

    Britprius Senior Member

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    Sorry, my misunderstanding of your post.

    John (Britprius)