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Brake fluid change with TechStream - question

Discussion in 'Gen 3 Prius Care, Maintenance & Troubleshooting' started by RWD, Sep 27, 2021.

  1. RWD

    RWD New Member

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    Hi!
    I have to change brake fluid on my '09 gen3 Prius. I have TechStream, Mangoose cable, everything what is needed for process. According to the manual, i have to set the car "ACC" mode while doing the brake fluid change/bleeding. But my 12V battery seems a little old, i fear from 12v battery dead under the bleeding process. Could be a smart idea to connect a battery charger to the 12v battery. Someone says it's ok, there is nothing to worry about. Other ones say the charger could harm the inverter, even in "ACC" mode.
    What do you think? Maybe I could try the process in "READY" mode, without the external charger of course. But TechStream says you should do the process in "ACC".

    Do you have any experience about? Thank you in advance!
     
  2. Mendel Leisk

    Mendel Leisk Senior Member

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    I've had a smart charger (CTEK 4.3) hooked up while doing a brake fluid change on 3rd gen, no problems. FWIW, I was using the non-Techstream method (outlined in 3rd gen Repair Manual). For 2nd gen the Repair Manual does not have a non-Techstream method, but I don't see it being a problem. There are some procedures (software updates?) where it's actually recommended to have a charger running, for just-in-case.

    Have you got the 2nd gen Repair Manual procedure? I can post if you need.
     
  3. ChapmanF

    ChapmanF Senior Member

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    At the dealer, they'll hook a big honkin' charger to the 12 volt battery for any procedure where the battery could get run down. It doesn't hurt anything.

    [​IMG]
     
  4. RWD

    RWD New Member

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    Thank you! I have this type of charger: CTEK MXS 3.8 (can not insert a link, because of my newbie status:)
    I hope to using this charger is acceptable for this process. I have the manual of 3rd gen Prius, but I appreciate your offer!:)
    So it is absolutely safe to hook up a charger on the aux. (12v) battery, while i'm doing brake fluid change in "ACC" (accessory) mode. Doesn't hurt anything, neither the inverter itself. It could be an expensive disaster, if i kill it...:)
     
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  5. Mendel Leisk

    Mendel Leisk Senior Member

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    Nothings “absolute”, but ours was fine. :)
     
  6. RWD

    RWD New Member

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    Thank you, and sorry for my rubbish english :)
     
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  7. Mendel Leisk

    Mendel Leisk Senior Member

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    What rubbish, looks fine to me.