Grinding/Scraping noise at low speed

[Osca]

Hi , I have recently changed my front and rear pads and discs on my e220 w213 but I I’m still getting a really annoying grinding/scraping metallic sound literally just before I come to a full stop or when manoeuvring at low speed , for example parking my car , or stopping and starting in slow moving traffic more commonly . This noise will temporarily go when I do a bit of harsh braking but then after a while comes back again . It’s a bit worse when stopping on a downhill road , but it almost completely goes when stopping on a uphill road . This noise only comes right before the car comes to a full stop when braking . It’s very annoying , anyone have any suggestions what it can likely be ?

This sound was also there before I changed any of my pads and discs

 

[StMarks]

As your pads wear down, the caliper pistons protrude further & further.
The longer replacement is left, the greater the opportunity for the protruding piston sides to become soiled (or in extreme circumstances, corroded).
If the pistons were to be manipulated back into the calipers, without first being inspected/cleaned, it is possible that the detritus on the piston walls could prevent them from moving freely, so rather than retracting slightly to leave a running clearance they maintain some pad contact (hence the noise).
By the same method, the cause could equally be the caliper sliders/pins.
Hth.

 

[Bellow]

Hi , I have recently changed my front and rear pads and discs on my e220 w213

How recently? Ie, how much respite from the noise after the disc/pad change before it reappeared?

 

[Osca]

There was no noise at all after the pads and discs were changed but then the noise reappeared around a week later , I drove around 400 miles during that time . I’ve found something strange today , If I turn the wheel slightly just before coming to a full stop there is no grinding sound .

 

[BlackC55]

I would be looking at the brakes again and possibly the front wheel bearings.