2010 Prius w C 1391 code - anyone replace pump assembly (accumulator...)

Discussion in 'Gen 3 Prius Main Forum' started by JCEze, Aug 14, 2020.

  1. JCEze

    JCEze New Member

    Joined:
    Jul 18, 2020
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    Location:
    HUntsville, AL
    Vehicle:
    2011 Prius
    Model:
    III
    So I have a 2010 Prius with the C1391 code, accumulator leak malfunction according to TIS. Can be one of two parts (brake master cylinder p/n 4705047140 or pump assembly/brake booster aka accumulator p/n 4707047060) says the TIS. Note that the car is just out of recall window for the accumulator and Toyota was a hard NO on any help, especially since the accumulator had been replaced once already by the previous owner.

    Looking into the TIS since I am a decent DYI type, the manual says to replace the pump/accumulator, one must first remove the brake master cylinder (which could be the problem anyway) and the front suspension cross member. That second part there put me out of the job. Has anyone done this job without removing the front suspension cross member?? The issue is obviously Toyota thinks you need to access the bottom of the accumulator, which I cannot exactly agree w based on the drawings, but diving into this and being wrong would be bad.

    The TIS does define a test to watch the wheel cylinder pressure sensor to decide which part is bad, but I do not have access to Techstream. Since the manual says take the master cylinder out and it might be the problem, I am looking at doing both parts (I can get new OEM w a discount for around $550 each).

    Long story here, but in a nutshell the concern is replacing accumulator without removing front suspension cross member. Thoughts??

    Thanks in advance!!!
     
  2. JCEze

    JCEze New Member

    Joined:
    Jul 18, 2020
    4
    0
    0
    Location:
    HUntsville, AL
    Vehicle:
    2011 Prius
    Model:
    III
    Well now..just found the tech bulletin on replacing the accumulator. Pretty much answers it all.
     
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