scary sudden braking problem

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by Ofer Nave, Nov 2, 2019.

  1. Ofer Nave

    Ofer Nave New Member

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    A month ago I bought a 2008 Prius.

    About a week ago, I started noticing the BRAKE light - which is only supposed to be on when the parking brake is engaged - would randomly turn on while I was driving and stay that way for five or ten minutes, then go away.

    A few days later, I was driving towards a red light when suddenly the BRAKE light came on again, along with three other warning lights - brake system, ABS, and VSC, which are all in a row on the panel. At the same time, it suddenly felt like my brakes had stopped working. I would press but it resisted hard and barely slowed down. I managed to come to stop just before the light.

    Afterwards, I had no choice but to keep driving, even though the brakes were barely effective, and gas pedal felt sluggish, and I thought I felt extra heat through the vents - almost as if I was driving with the parking break on.

    Since then, this has happened another dozen or so times, coming on randomly, staying for a random time (five minutes or twenty minutes), then disappearing. Turning the car off and back on again doesn't seem to effect it - the one time I tried while it was experiencing the problem, it came back on with the problem.

    Anyone heard of anything like this? I took it to a mechanic this morning, but they had no luck figuring it out - couldn't get it to happen for them, and the computer reported no stored errors.
     
  2. ChapmanF

    ChapmanF Senior Member

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    The parking brake is only one of the reasons that light can light up.

    It's not unusual for any of the things that can go wrong with the brake system so it drops into its failsafe mode where your foot pressure is what's making the brake force.

    The key is to get the trouble codes read. The mechanic saying there weren't any doesn't help; perhaps there is a dealer or someone near you with Toyota Techstream or a reader capable of getting the codes. If the mechanic did something to clear them, there may be no retrieving them until they come back, which it sounds like they will.

    Without needing any scanner, there is a way to extract abridged versions of the codes with a jumper wire between the Tc and CG pins at the diagnostic port.
     
  3. TMR-JWAP

    TMR-JWAP Senior Member

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    Not trying to be a jerk, but everyone always thinks they absolutely must keep driving, as everything we're doing is so important. Until brakes totally fail and you die....or kill someone's kid.

    Does reading the below statements send any second thoughts through your mind?

    Afterwards, I had no choice but to keep driving, even though the brakes were barely effective, and gas pedal felt sluggish, and I thought I felt extra heat through the vents - almost as if I was driving with the parking break on.

    Since then, this has happened another dozen or so times, coming on randomly, staying for a random time …...
    because your life and others around you aren't important enough to get it correctly diagnosed and repaired?

    It's going to be a lot more exciting when you slam into the back of another car or run someone over. But, at least you won't have to worry about the brakes anymore, as you won't even have a car...
     
  4. Ofer Nave

    Ofer Nave New Member

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    I'm going to ignore the jerk who knows nothing about my life situation and is not being even slightly helpful.
     
    bisco likes this.
  5. TMR-JWAP

    TMR-JWAP Senior Member

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    I'm glad you think trying to save your life or someone else's isn't being even slightly helpful.

    So let's assume someone else is doing the same exact thing with the exact same car problem. They slam into a car filled with your family members and kill or cripple a few. It's ok, right? Because they really needed to run down to the 7-11 for a coke driving a car that should NOT be on the road in it's current condition. I'm sure you'd just let it slide, no big deal, right?

    Good luck. And yeah, do some research on Prius brake problems. You'll get thousands of results describing brake actuator failures in the Gen 2. It's not that tough.
     
  6. Ofer Nave

    Ofer Nave New Member

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    If I'm going to get bullied by the PriusChat version of an SJW while trying to get help for a real problem, I'm going to leave this forum.
     
  7. TMR-JWAP

    TMR-JWAP Senior Member

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    really? bullied because I'm telling you straight? If being told the truth is hurting your feelings, there's a term for that also. Something similar to what happens when clouds release moisture and it's less than 32 degrees.You are correct. You have a REAL problem. Your brakes are in the process of failing. That's why Toyota has clear instructions in the owner's manual that the corrective action for certain warning lights, like the ones you're receiving, is to immediately pull over and stop the car. Yet you insist on driving. Blame me all you want and call me what you wish. I must admit it's the first time in my life I've ever been called a SJW. But I really dgaf. I've helped more people with car problems than you've probably ever met in your life.

    Here's your help. You're 99% likely to be experiencing brake system failure. Do a search for prius brake problems. (I think it was mentioned earlier). Do a search for Prius brake actuator. You're not going to like the results. The Gen 2 uses a hydraulic reservoir system that is pressurized by a pump. Sometimes that pump and accumulator system start leaking and it won't hold pressure any more. That is probably what you're looking at. Take your car to a REAL Toyota mechanic or dealership. The one you're using isn't even able to read a code, which IS there. Open your checkbook or bust out the plastic. Or just keep driving until you wreck. You don't want to listen so choose your own medicine.

    I suppose I can tell you what you want to hear? Oh, it's all fine. Just a flickering light. probably just a loose wire. Maybe just a weak 12v battery. Should be no worse than if a courtesy light bulb burned out. Drive on.
     
  8. ChapmanF

    ChapmanF Senior Member

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    If the OP ever comes back, it might be useful to filter out a lot of the words and just focus on getting the trouble codes read (somewhere that doesn't say there aren't any) and post those.
     
  9. frodoz737

    frodoz737 Top Wrench

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    Ofer Nave...the advice you were given is sound and correct. There is an abundance of mechanical knowledge and experience about Prius on this forum. While there is also an abundance of SJW BS here too...don't cross your wires...or your issues.
     
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