Brakes on a W124 E280

[Stu_CDX]

Hi guys,

As in my introduction thread, I was wondering if someone could shed some light on this.

Occasionally, when braking from 40 or so, there is a droning noise from the front brakes. It's not all the time and the brakes work perfectly. It seems to be then the brakes are hot or I've given them a good poke the time before.

The ABS is working perfectly and they stop you very well.

The pads look ok and as it's got alloys, I could stick my finger through and give the disc a feel and it feels pretty well to me.

Cheers,

Stu.

 

[Bolide]

Difficult to say - but if you change the fRont discs & pads I bet it'll go away

Nick Froome
www.w124.co.uk

 

[wireman]

As Nick above, your disks are begining to warp or they are worn in thickness and the pads are rubbing radialy on the wear ridges around the edge of the disk, it only need be an almost imeasureable few microns to be noticable.

I too have found that vented disks can groan under very heavy use, perhaps this is due to the rubbing surface bending away from the pads under the ton or two of applied pressure, I don't know a real reason and am only speculating on this point but a few nanometres of motion would be sufficient to produce audible results.

Warping can be the result of bad driving habits, stopping from speed and holding the brakes on leaves a very hot area on the disk where the pads are, the differential cooling of the disk as the car stands still leaves the disk out of shape and this becomes a permanent distortion as a result of repeatedly doing so, this amounts to poor driving habits and a lack of car sympathy in my book.
Use the parking brakes to prevent rolling when you stop, just as you were taught and this will not happen.

Try glaze busting your disks it might just cure it, just scrub them with medium/fine glass paper in a sort of random spiral on both sides untill the shine has gone off.