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Brake booster problems

Discussion in 'Gen 3 Prius Care, Maintenance & Troubleshooting' started by vkolli, Jun 12, 2024.

  1. vkolli

    vkolli Junior Member

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    About 5 months ago, while driving Brake, ABS, Traction, slip lights suddenly turned on in my Prius 2010 - 165K miles. Braking was also weak. I could hear the whirring sound from the brake pump every few minutes. Error code was C1391, the mechanic replaced both the ABS Brake booster pump (accumulator) - part#47070 47060 and Brake master cylinder (actuator), part#47050-47140 and calibrated. To save money I had them replaced these with used parts I purchased from eBay. Everything seems to be working for three months and ~1000 miles. But the same lights came back again. But this time I do not hear the whirring sound from the brake pump. Brake pedals feel hard but I can brake and stop the car. It brakes better than last time I had the issue, but do not feel it’s 100% right. Same mechanic repeated the recalibration. But it did not fix the problem. He thinks the replaced parts might have failed. Since I procured the parts he wouldn’t warranty the fix. But given that I am not hearing the whirring sound from brake pump like last time, I am doubting his diagnosis. I already spent over $1200 last time and I am back to where I was with this problem.
    Another strange thing is these warning lights occasionally goes away for a few min but are on most of the time and comes back on after I restart the car. There should be no issue with the 12V battery as it was replaced 5 months ago (around the same time I had the braking issue originally).
    I really need to have the car working for couple of more years. Any suggestions on what I can do or check to figure out the problem.
     
    #1 vkolli, Jun 12, 2024
    Last edited: Jun 12, 2024
  2. ASRDogman

    ASRDogman Senior Member

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    "To save money I had them replaced these with used parts I purchased from eBay."

    Used parts for brakes are NEVER a good idea! Never.
    And from ebay, doubtful they are the correct parts for YOUR Prius.

    You kinda have 2 choices. Find a shop that works on Prius'. Or take it to Toyota
    and have they check it out.

    They have the correct parts for YOUR Prius, and know how to install them and get them
    working correctly.
    Since you need the car for a few more years, fix it correctly. Plus you'll be able to sell it for
    more since you had the work done at Toyota.
     
    #2 ASRDogman, Jun 12, 2024
    Last edited: Jun 12, 2024
    Mr. F likes this.
  3. worldaven

    worldaven Member

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    I had this done at the dealership because my independent mechanic didn't have the equipment to do it. It cost me $3300 plus had to rent a car while the part was ordered and replaced. Any gas savings from the last 14 years disappeared with that one repair.
     
  4. bisco

    bisco cookie crumbler

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    a prius is never a good choice when trying to save money, unless you can do all your own repairs.
     
  5. vkolli

    vkolli Junior Member

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    OP here. Thanks for all responses. In my case, the parts that were used are correct and are verified by the mechanic. Mechanic is also one that specializes in Prius (Hybrids). Also it is not that the changed part is bad to begin with as it worked for some period of time. It could be my bad luck that these parts have gone bad twice. What is annoying is that we have to change both parts together every time. There seems to be no way to diagnose which part is bad - as per this mechanic.
     
  6. ChapmanF

    ChapmanF Senior Member

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    Well, people try fixes where they haven't got a complete diagnosis all the time ... they'll usually change one thing, and if that didn't do it, change the other.

    It's always nicer to be able to pin it down first, but not being able to doesn't mean you have to change both every time.