e70 X5 Brake DIY Question.

[Thirdy]

Originally Posted by JCL

There is more to it than the remaining rotor thickness, although that is a good place to start. You need to evaluate the surface finish of the rotors, look for hot spotting, and so on. Many times it is possible to reuse rotors, whether front or rear. Many of us don't do so, because it isn't worth our time to have to go back in and do the brakes again if we get pad noise after not replacing the rotors. There isn't a lot of meat on BMW rotors (likely due to a decision to reduce unsprung weight). You can't turn them, which used to be standard practice. If they get too thin, you will have problems, probably more to do with increased brake fade than with warping.

Many shops (including dealers) replace rotors as standard practice due to their desire to reduce service warranty redo whereby customers come back and ask the shop to redo the brakes because of squealing post pad change.

No, not all dealers replace rotors. I have had 2 instances where my e60 needed a brake pad replacement and I tried to insist that they also replace the rotors but they said it is still within spec. Same thing with my E70 when pads were replaced again I tried to tell them to replace the rotors too but NOPE they didn't replace it. So it's not always the case that everytime you replace brake pads that the rotors also need to be replaced.