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Strange "thudding" while braking

Discussion in 'Gen 3 Prius Care, Maintenance & Troubleshooting' started by lohikaarme, Sep 21, 2016.

  1. lohikaarme

    lohikaarme Troll

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    hey guys i am wondering if anyone has ever experienced this...
    it is not consistent but lately when i brake i hear a strange " thudding" that seems to be coming from either the wheel well or deep in the engine. The sound is in quicker intervals if i am traveling faster but i only here it at slow speeds like when driving sround the neighborhood.

    It is really hard to describe the sound. It reminds me of a boat like creak that i have experienced with older cars with worn bushings taking a turn. It is not a high pitch squeal, it is not a grinding, and it is not worn bushings. It does not happen when im turning vs going straight. Its just a low thud, thud, thud. Almost like as if you wet your hand and then rub it over a balloon in a more systematic interval.

    Any possible clues on what could be going on? This is a 2012 that just crossed 50k miles.

    Thanks...!
     
  2. lohikaarme

    lohikaarme Troll

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    I should add there is only a sound. No vibration is produced
     
  3. Mendel Leisk

    Mendel Leisk Senior Member

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    Pull the wheels and have a look, or get it in for inspection. My first (nasty) thought is a cracked rotor, but I could be way off.

    But yeah, strange new sound when braking, you want to find out asap.
     
  4. lohikaarme

    lohikaarme Troll

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    So I took a look, removing each wheel and inspecting and it all looks normal, however, I did notice that my brake fluid was about 1cm below the low line. I just topped it off and I have not been able to test yet t see if that was the cause. I am hoping that this turns out to be the root of the issue. In more testing I only hear the sound (sometimes)- and at very low speeds.
     
  5. Mendel Leisk

    Mendel Leisk Senior Member

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    It's seems to be my lot to rain on everyone's parade, lol. Anyway:

    It's natural for the fluid to go down, it tends to follow the pad wear, and typically when the pads are near replacement the fluid will also be near the low level. Push the piston back in to accommodate new (thicker) pads and the level goes back up. In your case now, when you replace pads I would keep that top-up in mind, you may need to baste out a bit.
     
  6. lohikaarme

    lohikaarme Troll

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    Some new information ... I did some tests. It turns out the spund is still there at low speeds but only when i have my wheel cut slightly to the right and i am braking. A rubbery clicking sound. Going straight or cutting to the left nothing. Cutting all the way to the right nothing. It seems like the range is steering wheel a few degrees to half a turn to the right and its the range where it sounds.

    I am thinking either the cv joint or bearing? It does not appear that there is anything making contact with the tire and i cannot isolate what side it is coming from
     
  7. bisco

    bisco cookie crumbler

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    how many miles on her?
     
  8. lohikaarme

    lohikaarme Troll

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  9. bisco

    bisco cookie crumbler

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    idk, a wheel bearing or cvj would be more constant i think?
     
  10. lohikaarme

    lohikaarme Troll

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  11. Rebound

    Rebound Senior Member

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  12. lohikaarme

    lohikaarme Troll

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    That's it! that sound file is exactly what I am hearing!
     
  13. lohikaarme

    lohikaarme Troll

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    So as an update to the saga... I pulled off the splash guard and inspected. No torn boots on the vc joints. I do have an appointment to get it checked out at the dealership on monday but i bought a set of rotors and pads today and did a front brake job. The original pads were nearly on the markers. As advised, the brake fluid went way above the full line but i leveled it back out. The brake job went well, however, the sound remains so it really is boiling down to the bearing or the vc joint. The sound is just like the clip that was posted but it is only when i am braking, moving slowly and have the wheel at like the 2 o'clock position. As it isnt clicking when i am turning dramatically and only when imam braking i thought i might get lucky with just doing a much needed brake job. At the very least, i narrowed it down for the toyota tech and will leave the splashguard off so they can see more clearly without pulling too much of the car apart.
     
  14. jennymarie417

    jennymarie417 New Member

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    Can you let me know what you find out? I'm having the same problem with my Prius! The guy in the post said it was an axel issue. I messaged him to find out more info...Hopefully he's still active.

    My dealership, when I took my car in, said absolutely nothing was wrong...but it still makes the noise

    Posted via the PriusChat mobile app.
     
  15. lohikaarme

    lohikaarme Troll

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    So as an update I went to the dealership and after about 3 hours the tech cannot determine if it is the bearing or the CV joint but really thinks it is the bearing. I advised them, via my search and data gathering here that it was the CV joint but I can understand them wanting to change the bearing first because it is the easier fix. Unfortunately it also means they are only ordering the bearing and if it does not work then they will order the CV joint (2 trips to the dealer now possible in addition to today). They do not want to order both because he really thinks it is the bearing and does not want to have to worry about sending anything back.

    Not so much of an issue I suppose as the tech says he can reproduce the issue all day long so we will know right away if the bearing fixes it.

    Now at 4 years and 51k miles this is all being covered under power train warranty so if it the bearing or the CV joint it does not matter. The next appointment will be on Wednesday morning so standby for an update.

    On a side note, I roamed around the dealership. I saw a red 2016 package 4 prius with a tan\dark gray interior! I did not think this was possible. I thought only the dark interior was available with the red. The website does not allow you to select anything but the dark interior as well. Has anyone ever seen this? How did this happen? It makes me want it. I will snap pics on Wednesday if it is still there.
     
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  16. Mendel Leisk

    Mendel Leisk Senior Member

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    There should be a law against having the showroom within walking distance of the service department, lol.
     
  17. lohikaarme

    lohikaarme Troll

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    Went to the dealership, they put in a new bearing and..... Nope problem remains. It is the cv joint and of course they only ordered the bearing so i will need to go back when they get the joint in. Let it be known, this ticking, the wav file referenced: this is a cv joint issue!!

    All being covered under warrant. Received a free bearing out of it.

    Spent some time looking at the new prius. Im womdering if i were to buy a 4 and wanted to add a spare tire, if i buy the foam would it even fit? I took apart the rear of the demo model and it didnt look like a spare would even fit back there even if the foam was different. I will upload so e pics of the car.
     
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  18. lohikaarme

    lohikaarme Troll

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  19. Mendel Leisk

    Mendel Leisk Senior Member

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    Get a 2 or 3? Save some bucks, get a spare. With 2 I think you can even forgo the ($200 retail) black trim of the white centre console, just keeps getting better.

    Me, I'd be scanning the lot for left over 2015's. Just a rant, lol.