[mJ335]

Hi guys,

My car is at 71,652 and the brake light just came on... so I went to a bodyshop that specializes in BMWs (knowing that stealerships will rip me off) and they tell me that the brake service consists of changing brake pads, brake sensors... and ROTORS?! My rotors are fine (no hot spots), only the brake pads are worn.. so my question is, is it absolutely necessary to replace brake rotors at 71k miles? Or are they just trying to take my money as well? Any helpful input would be greatly appreciated.. thanks!

[Slow_335i]

If they've never been changed it may be the best time to do it now and save the extra labor cost next time.

But really if theres enough "meat" on them you should be good.

[Meeni]

Its not abnormal to change rotors at this mileage, if they are not completely done, they are close. If you don't trust "them" you can check they are within spec yourself (vw video, but same for us)

spec if 20.4mm on 335i .

[Efthreeoh]

So here's my opinion on the question from 25 years of experience with DIYing BMW brake systems.

You can leave the rotors and just change the pads at 71K. However you will find that the new pads will last longer than the original rotors. This is usually the case because OE BMW rotors are somewhat "soft" and wear while in service and usually do not last through two sets of pads and end up with warped rotors and 35% pad life left (estimates).

Additionally, an ideal brake "relining" includes removal of the rotors and resurfacing them on a brake lathe. The resurfacing removes even more rotor material and makes them more susceptible to warpage from heat as the rotors continue to wear. All that said, it is just better to replace the rotors and pads as a set since some of the cost of the brake job should be for resurfacing the rotors, which can be offset by just buying new rotors instead. Meaning, if it costs $20 to resurface one rotor and a new rotor costs $65, the $20 is better spend just getting a new rotor.

[queensfield]

Great advice and I had the exact same experience. Best to replace both rotor and brake pads. Make sure you use a new brake wear sensor at the same time and it is installed correctly (otherwise it makes a squeeky noise at low rpms).

[Fitz335]

How big of a lip on the rotor would you consider to be "worn"?

[mJ335]

Thank you for your great advice! After looking through, I decided to change everything (rotors, sensors, pads), just to think of saving money in the long run.. appreciate your input.

[dd243372]

Good thread. Answered a question I was wondering myself.

[r111]

I'm a free way driver so, my third set of pads are installed when the car is at 150,000 miles. The rotors are fused to the hub, and are hard to take off. You have to get really good with aiming with the hammer.

Make sure the shop uses anti-seize paste on the hub to rotor mating surface. It will save you trouble later down the line.