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Replaced caliper and did brake fluid flush without knowing about Techstream or Invalid mode

Discussion in 'Gen 3 Prius Care, Maintenance & Troubleshooting' started by Hieu Tran, Oct 3, 2018.

  1. Hieu Tran

    Hieu Tran New Member

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    Hi all,

    My first post in the forum, so I will go fast.

    I've replaced the calipers, rotors and pads, all rear, for my wife's Prius 2011 in the normal way without knowing or doing anything about the Techstream or Invalid mode. Somehow everything works just fine after the job, but should I worry about it or is there anything I should check to assure safety?

    Basically, I just followed some DYI videos about doing the brake jobs. I jumped right in doing a full fluid flush, replacing the rear calipers, rotors and pads, then bleeding the fluid at the rear lines before putting the wheels back. At first the brake system did not seem to work (soft pedal, cannot power on the car as all lights are on). I left the car there for work, and right before heading back home to try with another fluid flush, I found videos, posts, articles, etc. talking about doing the car job on a hybrid vehicle and the Techsteam/Invalid mode stuff.

    Worrying that I had broken the system and would have it towed to a dealership, I tried powering the car again by pressing the pedal multiple times, changing the gear and turning the power button on and off. Then magically the car just went on like no issue had ever happened. I did a road test and the brake seemed to work well.

    Any ideas about why that worked or what I should check now.

    Thank you,
     
    #1 Hieu Tran, Oct 3, 2018
  2. tankyuong

    tankyuong Senior Member

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    If it works with no lights you’re good
     
    #2 tankyuong, Oct 4, 2018
    Raytheeagle, Hieu Tran and Mendel Leisk like this.
  3. ETC(SS)

    ETC(SS) The OTHER One Percenter.....

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    +1

    Welcome to PriusChat!
     
    #3 ETC(SS), Oct 4, 2018
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  4. Mendel Leisk

    Mendel Leisk Senior Member

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    @tankyuong's advice is probably the best course: if the brakes are performing normally, you've no warning lights, you've dodged a bullet?

    Here there's a good video on doing the brakes without Techstream, using "invalid" mode:

    Nutz About Bolts Prius Maintenance Videos | PriusChat

    (video #18)

    The video shows very clearly how to do it. I particularly like the split screen explanation, pushing the brake pedal and open/close of bleed bolt, on the front brakes.

    Note, he does the brakes in different order from the Repair Manual, seems to work either way. Also, while he uses mechanized vacuum source, you can work without it, just rely on brake pedal pressure. The only time you REALLY need suction is to intially get old fluid out of the reservoir, and for that you can use baster, syringe, what have you. Whatever you use should have a very skinny tip, since to get to the bottom of the reservoir you need to fit through a narrow slit in strainer basket inside the reservoir.

    Also, I'll attach Repair Manual Instruction, also shows the Invalid Mode procedure, but the video is actually clearer.
     

    Attached Files:

    #4 Mendel Leisk, Oct 4, 2018
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  5. Hieu Tran

    Hieu Tran New Member

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    2011 Prius
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    Thank you all very much! Since I did not follow any proper procedure for Prius, I was worrying if anything could go wrong later. So far so good without any warning light.

    Then my other question is why is it so important to use the Techstream or put the car in Invalid mode? Why could I still go through that without using those techniques?
     
    #5 Hieu Tran, Oct 4, 2018
  6. tankyuong

    tankyuong Senior Member

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    Because it’s a very complicated machine
     
    #6 tankyuong, Oct 5, 2018
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