Tully122

HI ,i.have a Mercedes c220 blue efficiency sport 2011 recently I changed the rear pads and discs due to squealing sound I was getting, however now I have started getting a new noise from rear brake ,there is a spongy springy sort of sound when brake is applied and there is also occasional knock sound when coming off the brake, the brakes were replaced with OEM Parts at a independent Mercedes specialist .I went back and they took brakes off lubricated and sanded some surfaces and noise was gone but came back after a day , I took it back again and they put another set of new pads and it was fine for a couple days but has come back and now garage doesn't know what to do . I am including a link to a video of me pressing brake and noise that comes.Any advice will be appreciated

gamma300C

Does the noise go away if you apply the parking brake a bit while moving ?

Tully122

no ,the noise is constant.

Just204

they look at your suspension? doesn't sound like a brake noise to me...

superangrypenguin

Parking brake sound to me.

Try engaging your parking brake and drive (not all the way, just lightly). Does the noise change?

gamma300C

See post #2 and #3

superangrypenguin

Apologies, going through a divorce so head is in the wrong spot.

Have you tried lifting up the rear of the car (using a jack), and turn the wheels? I'm curious if the sound still exists?

If not, maybe a suspension issue. If so, definitely not related to the suspension