Replacement brake discs

[left98204]

My brake disc light has come on, however both front and back discs have a ridge on the outside of them.

I have already replaced one set of discs (can't remember which they were) a while agao.

My question is, how do I know which set is causing the light to come on, is there a way of telling, as I wanted to source replacement discs on the internet and supply them to the garage for fitting, but without knowing which are causing the problem I can't do that.

Any advice welcomed.

Cheers

 

[Tref]

I thought the light meant that the pads were worn. There is a metal contact that is made when the pad gets down to a certain point. Discs are probably OK, a lip is just a bit of wear. Post a pic if you're not sure. Dealers will tell you they need replacing though... Just check that the friction area (where the pad hits) is clean and polished (i.e. used) on both the inside and outside.

 

[srhutch]

As above your pads are shot, depending how you are on the brakes will depend if you need news disks or not, normally I have to replace both at same time

 

[Aebous]

Yeah that light is only for your pads. It's up to you/your mechanic to determine if the rotors are worn to the point they require replacement. That lip that you see is just because the pad is not covering all of the rotor. It did it on mine, I purchased aftermarket pads/rotors and now no lip and way way less dust.