AC compressor noise when brAking

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by Johnny KIlo, Nov 5, 2015.

  1. Johnny KIlo

    Johnny KIlo Junior Member

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    2005 Prius
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    II
    Quick back story, bought the car a year ago, seller told me it was in an accident and the radiator was replaced. He let me know that the discharge AC hose was missing and that the other hose was disconnected. I also noticed that the low pressure cap is missing. I recently ordered and installed the discharge hose with the intention of filling the system later.

    I have always noticed a noise/vibration coming from the passenger side when braking at low speeds. I havent noticed at higher speeds but maybe there is more road noise. The best I can describe the noise is that is sounds like a compressor running. I have a hunch it's the AC compressor and might be related to the regenerative braking, but I am no expert.

    My first question is, what's the best way to go about testing and filling the AC?

    Also, could my braking noise be related to my AC?
     
    #1 Johnny KIlo, Nov 5, 2015
  2. Marcipaw

    Marcipaw Junior Member

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    Sounds like brake actuator, try pumping brake pedal while parked with engine off, ignition on and "ready" on just to confirm that it is the actuator that you are hearing. As long as you dont get any vsc, brake and ! lights on the dash it is all normal
     
    #2 Marcipaw, Nov 6, 2015
  3. Johnny KIlo

    Johnny KIlo Junior Member

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    No lights, I have the VCI to confirm, I haven't seen any codes related to the braking system. I do have the maintenance required light on but I think that's due to my AC pressure.

    I tried to record the noise on my phone, it's kind of hard to pick up. Don't turn your speakers up all the way, my GPS went off around 15 seconds and its really loud. The noise is around 20 seconds. I'll try to get a better recording

    I tested per your instructions and did notice a noise but it wasn't the same noise. It's sounded mechanical, as if something was opening and closing. I also noticed noise coming from the inverter area, I suspect the pump. Neither of the noises were particularly loud and sounded "normal" at least by my own estimation.

    It could very well be a normal noise for the car, it seems excessively loud to me. It's always been there, the seller told me it goes away when the cat warms up which I generally agree with. For what it's worth I was driving a coworker and he noticed the noise as well on his own. By chance he also drives a Prius, albeit a 3rd gen, but I would except him to know if it was a normal sound.

    I'm going to treat it as related to the AC and get that fixed. Any advice on that front?

     
    #3 Johnny KIlo, Nov 6, 2015
  4. Mendel Leisk

    Mendel Leisk Senior Member

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    Might be the regen braking sound? That's normal.
     
    #4 Mendel Leisk, Nov 6, 2015
  5. JC91006

    JC91006 Senior Member

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    If you bought the car with that noise, it might be something that was damaged during the accident. I've heard that noise before, it might actually be coming from the transaxle.......a failing one.
     
    #5 JC91006, Nov 6, 2015
  6. Marcipaw

    Marcipaw Junior Member

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    Come to think of it I had something similar and replacing 12 v battery resolved this problem, had to do with regenerative braking system but how and why I dont know
     
    #6 Marcipaw, Nov 6, 2015
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