1. Attachments are working again! Check out this thread for more details and to report any other bugs.

Confusion on 2012 used Prius C three Master Cylinder break replacement

Discussion in 'Prius c Main Forum' started by thefyn, Jun 14, 2024.

  1. thefyn

    thefyn Junior Member

    Joined:
    May 3, 2012
    30
    7
    0
    Location:
    Treasure Coast
    Vehicle:
    2012 Prius c
    Model:
    Three
    I was told my 2012 prius c three needs master cylinder re breaks. I'm seeing two different looking items pop up.

    See attached. Symptoms are break pressure issue where the pedal seems sticky and breaks intermittently fail when pushing down.

    So which one would I need to get to solve the pump issue? Mine has the 15" wheels if that matters.
     

    Attached Files:

  2. ChapmanF

    ChapmanF Senior Member

    Joined:
    Mar 30, 2008
    24,913
    16,216
    0
    Location:
    Indiana, USA
    Vehicle:
    2010 Prius
    Model:
    IV
    The one with a plunger attached to the brake pedal that's pushed in when you brake is the master cylinder. Of your two pictures, it's the shinier one. :)

    It's also probably the one you need.

    You were told, by whom? Are there any warning lights showing on the dash?
     
  3. thefyn

    thefyn Junior Member

    Joined:
    May 3, 2012
    30
    7
    0
    Location:
    Treasure Coast
    Vehicle:
    2012 Prius c
    Model:
    Three
    Thanks man. Off the top of my head the lights (along with beeping) are the attached. I'm not near the car now for my actual dash but I think this image is it. Initially I told the Toyota dealership of the problem and they said it passed their tests. The warning was intermittent and not happening when I took it there the first time. Now there is a whirring sound every 20 seconds like it's trying to engage whatever failed. I took it there when it was lit up like a Christmas tree on the dash but the breaks worked and then they told me (despite the breaks working) that the master cylinder needs replacing soon and I trust them. I just want to get a used one as the new price is nuts.
     
  4. thefyn

    thefyn Junior Member

    Joined:
    May 3, 2012
    30
    7
    0
    Location:
    Treasure Coast
    Vehicle:
    2012 Prius c
    Model:
    Three
    Image attached
     

    Attached Files:

  5. ChapmanF

    ChapmanF Senior Member

    Joined:
    Mar 30, 2008
    24,913
    16,216
    0
    Location:
    Indiana, USA
    Vehicle:
    2010 Prius
    Model:
    IV
    The whirring is the normal sound of a pump that makes up your braking pressure. The not-normal part is the pump having to run so often; when the system is tight the pressure will hold up a long time (hours-ish, if you're not using the brakes) before the pump has to run again.

    The master cylinder probably is what you need. For future situations (and for other readers), when you have those brake warning lights on, you can get the trouble codes right away, like this:

    Blink (a/k/a Flash) Codes – How to. | PriusChat

    That can save precious time on waiting for somebody else to tell you what's wrong.
     
  6. daffodilistic

    daffodilistic Junior Member

    Joined:
    May 2, 2023
    2
    0
    0
    Location:
    Singapore
    Vehicle:
    2015 Prius c
    Model:
    N/A
    Based on my recent experience, your brake actuators (which have the pumps on them) are about to fail. You should get ready spares, money and time to get it fixed.