I have replaced both sides of my 2014 Sonata and it is very loud when broken. I've been driving it for 4-5 months now, the knocking persists. I checked the drive pin rubber and both were lubed and I even swapped out the brake hardware to minimize the noise, but it was noticeably noisy under braking and even daily driving. Luckily, noise isn't that important to me because I don't use this machine that often, but for those who make noise, it quickly becomes annoying over time.