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Mild clunk sound starting and stopping when applying brake

Discussion in 'Gen 4 Prius Care, Maintenance and Troubleshooting' started by PatricioDaSilva, Apr 17, 2022.

  1. PatricioDaSilva

    PatricioDaSilva New Member

    Apr 15, 2022
    San Diego
    2018 Prius
    I hear a mild clunking noise when I apply the brakes in low speed and taking off. No code for it. I'm thinking the grease in the outer CV joint is too thin. Anyone have an experience with a soft clunk sound when applying brakes stopping and starting? This is actually been happening for a couple of years, now, not long after I bought the car ( new ). After having a mechanic check my engine for another problem, he told me that sound wasn't supposed to be happening. I just thought it was an idiosyncrasy of the car.

    A google video told me it was the CV joint grease too thin in the outer joint., but yet another video says it was the brake pad shims not keeping the pad snug in place, just bend it back, he said.

    I hate cars. I want an antigravity machine that has no moving parts, you know, the kind aliens fly around in? :)
  2. BiomedO1

    BiomedO1 Senior Member

    Mar 27, 2021
    SacTown, Ca
    2021 Prius Prime
    Those are actually two very good guesses. Kudos for doing your homework. I'm assuming your CV boots are intact, no tears or leaks. To verify CV joints are noisy, find a large empty parking lot. Your going to drive around in large figure 8 pattern at low speed, to try to reproduce the problem; so a quite large area is optimal. Rotate your steering wheel from one lock position to the other and listen for the clicking sound. When the car is in a tight turn, the inner wheel will spin slower than the outer wheel - so if a particular CV joint is "crunchy"/bad you should be able to determine which side is bad. I believe there are other complaints about bad CV joints here and that the USA TSB has been recended, but the European one is still active. If your still within warranty, 5yrs 60K power train - have the dealer replace them.

    If it's the brake pad shims; the "clunk" should only be noticeable when you change direction of wheel spin. ie. park to drive or drive to reverse. I would think any auto tech should've caught that during your 4-5 free maintenance inspections; where they're suppose to check your brakes.

    Hope this helps.
  3. donroyledbetter

    donroyledbetter Junior Member

    Sep 14, 2013
    2010 Prius
    Brakes make horrible clunking screeching sound at the moment before complete stop and on release of pedal.
    Any one here with the same problem? A solution?

    This is my first post to PriusChat.
    You can hear the noise on YouTube by searching: @toyotafrenirumorosiscricch2355

    The noise started shortly after 7/21 new car purchase and has continued for 20K since. Has been to the dealer EIGHT times: they checked, they inquired to Toyota, they lubricated, they changed discs and pads, they reprogrammed a couple times. no change. We have appealed to Toyota Europe several times, they refer us back to the dealer who does not seem to care and points the finger at Toyota. The last reply from Toyota Europe was a patronizing: "The noise is caused by friction".

    I was very happy with my first new 2010 Prius, this one has been a total disappointment. That Toyota PR about relaxing warranty is BS.