How to assess / measure the generator life?

Discussion in 'Gen 3 Prius Care, Maintenance & Troubleshooting' started by gatorback, Jan 26, 2026 at 10:56 PM.

  1. gatorback

    gatorback Junior Member

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    Context: https://www.youtube.com/watch?v=VxOM1deFcbw

    S    aid video indicates that instead of an alternator, a generator is present. When the generator requires service / replacement it is a huge job in the sense that the motor / transmission has to be removed: a $6K job to replace the generator. I am pretty sure that my 2010 / 92K Prius is not worth $6K. That being said,

    1) What is the metric for assessing how much life the generator has left?
    2) How is the measurement performed?
     
    #1 gatorback, Jan 26, 2026 at 10:56 PM
  2. rjparker

    rjparker Tu Humilde Sirviente

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    The motor/generator almost never fails. That goes for the whole transaxle. If it ever did you have thousands of transaxles to choose from at the salvage yard, probably in the $500-$1000 range - primarily because no one needs one.

    The major parts you may need are the engine and the brake booster. They are the gen3 problem childs. The brake booster (master cylinder) is usually replaced with a new Toyota part.
     
    #2 rjparker, Jan 26, 2026 at 11:09 PM
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  3. gatorback

    gatorback Junior Member

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    [The major parts you may need are the engine and the brake booster. They are the gen3 problem childs. The brake booster (master cylinder) is usually replaced with a new Toyota part.[/QUOTE]

    Thanks for the reply. It sounds like this is something I do not need to monitor (my Prius is a 2010 with 92K miles).?

    When does it makes sense to replace the brake booster (master cylinder)? What is the earliest symptom / signal that indicates it is time to start thinking about replacing? Is this cause by the a clogged EGR?
     
    #3 gatorback, Jan 26, 2026 at 11:29 PM
  4. rjparker

    rjparker Tu Humilde Sirviente

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    The brake pump will run frequently, perhaps every 5 seconds. Some just wait until it fails and codes but you lose power brakes and stopping power. Not too safe. However it is a $2400 job at the dealer and a complicated labor intensive task with no rebuilt or aftermarket options.

    Like a lot of things, proactive planning can reduce the cost. Buy parts at online Toyota dealers during holiday sales and find an independent hybrid shop you cultivate with routine work before the emergency hits. One guy did this recently for $800 all in. Takes planning.
     
    #4 rjparker, Jan 26, 2026 at 11:41 PM
  5. PriusCamper

    PriusCamper Senior Member

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    Please do research with search engines and AI and thinking critically before asking! Gen1 Prius had some minor problems with electric motor-generator failure, but none in future iterations.

    For 2010 the weak points are head gasket failure, high MPG piston rings failing and burning oil early, bad EGR design that clogs and contributes to head gasket failure, electric water pump for engine that fails early.

    @Mendel Leisk has plenty more clarity/advice for you!
     
    #5 PriusCamper, Jan 27, 2026 at 12:01 AM
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