Dimples in rear brake disks

[DrooPG]

Hi All,
Just noticed 3 small (~5mm) dimples in the rear brake discs on my W205 C200.
Googling suggests they are either wear indicators or some sort of brake performance improvement feature.

Any suggestions?

DrooPG

 

[W1ghty]

Hi All,
Just noticed 3 small (~5mm) dimples in the rear brake discs on my W205 C200.
Googling suggests they are either wear indicators or some sort of brake performance improvement feature.

Any suggestions?

DrooPG

Picture ?

 

[SamW]

I understood a random dimple (kinda looks like it’s a small drill hole that hasn’t gone through) is for balancing purposes.

 

[Gazwould]

Wear indicators ?

 

[carat 3.6]

Hi All,
Just noticed 3 small (~5mm) dimples in the rear brake discs on my W205 C200.
Googling suggests they are either wear indicators or some sort of brake performance improvement feature.

Any suggestions?

DrooPG

Some discs have sets of 3 dimples spaced around the friction surface as "pad scrubbers", they work in the same way as grooved discs.

 

[Petrol Pete]

Some disc manufactures put a few dimples on the swept surface of a solid disc to allegedly allow the pad to 'gas/scrub out' , you don't see many of them around and almost all (normal) MB cars have non drilled/slotted rear discs as standard.

IMHO the vast majority of road cars could quite happily get along with plain discs all round that would probably improve both day to day performance and vastly improve pad life.

That was almost always the case OEM . until.......the disc could be seen through the (now common) alloy wheels , so holes and/or slots are now a 'must have' ....

Nothing wrong with the discs you have on , just not OEM spec.