W124 Metal on metal noise (faint) at high speed

[TwistingMyMelon]

e320 c124 coupe

I seem to have a faint metal on metal noise coming from rear passenger side wheel.
Always stays the same, regardless of speed, just you can only really hear it at low speeds in residential areas with window open. Not sure why I put "high speed" in title as you only notice it at 30/40mph in built up areas with windows down!

Normally I would say, sticking calliper, low pads, or wheel bearing
Seems to be coming from the brakes, as opposed the bearing
Pads have plenty of life left in them and there isn't any excess dust or heat that I would associate with a calliper sticking on after driving.
Also had the car serviced a few weeks back and they inspected the brakes for wear

Are there any heat shields behind the disks that can work loose, or any other usual suspects?

Many thanks in advance

Edited by TwistingMyMelon on Tuesday 1st June 14:22

[bolide]

I'd suspect the noise is pad / disc. The rear calipers are a little prone to seizing as they don't get much exercise on most cars. As a result the rear discs are often very rusty

Nick Froome

[Beamish]

Try GENTLY applying the handbrake and see if this alters the noise. You may have something amiss inside the handbrake.

[TwistingMyMelon]

Cheers chaps, handbrake mechanism is a bit rusty from lack of use as I had a flat garage before and now I have a very steep driveway.

Main culprit is a pitted disk which usslightly catching the pads, so going to replace all the pads, disks and handbrake shoes.

[bolide]

I've just done the front brakes on an E320 Coupe. Discs & pads from Mercedes, with my discount, £100. Rears will be cheaper

Nick Froome