[DetectiveLoki]

So I'm changing new front/rear brakes for my car this coming weekend. I was wondering if it's okay to resurface the rotor? I called a couple of place and one of them said I only need to change the brake pad, and do not need to resurface the rotor because it'll make it too thin.

[Chris_506]

It is not recommendable to re-surface the rotors, when the rotor wear is at minimum spec, will only drop you "more" less than the spec, which is now going to foster cracking and/or failure of the rotor.

in newer 3 series BMW recommends changing rotors/pads/wear pad sensors when the cars light comes on and many vendors on here or websites sell good quality kits at good prices.

[DetectiveLoki]

Thanks for the heads-up. Would $200 to install the front/rear brakes a decent deal?

[Cripple]

Originally Posted by DetectiveLoki

Thanks for the heads-up. Would $200 to install the front/rear brakes a decent deal?

For labour that's not bad but if you know how to turn a wrench this is a fairly simple job.

[wdeerfield]

2 bolts and a hold down screw is all you need to loosen to do brakes and rotors.

[Meeni]

How many miles on the rotors ? Usually they are shot between 65-80k depending on your driving style, so its useless to resurface if you are close to this.

[DetectiveLoki]

Originally Posted by Meeni

How many miles on the rotors ? Usually they are shot between 65-80k depending on your driving style, so its useless to resurface if you are close to this.

Close to 47k miles at the moment. I do a lot of freeway driving. I'm actually going to get my friends to help me change the brakes tomorrow morning since he has all the tools.

[fibonacci]

The correct answer is "rotors can be surfaced as long as they are within spec - that the resurfacing will not reduce to beneath acceptable limits."

[DetectiveLoki]

So I decided not to resurface the rotors since my rotor isn't warped or anything. Took about 2.5 hrs to change the brakes. Reused the sensor because the ones that came w/ my HAWK HPS was kinda odd when putting it in.

The Hawk HPS definitely doesn't feel like OEM since it doesn't have the initial bite when stopping.

[Daily_Driver]

My indy repair shop strongly suggested new rear rotors, and not trying to resurface the old ones.

[Ilyas]

Is it a dealership BS that when you're changing pads - rotors should be changed as well?

[DetectiveLoki]

Only change rotor when it's totally worn out or warped to the minimum.

[Meeni]

Originally Posted by Ilyas

Is it a dealership BS that when you're changing pads - rotors should be changed as well?

Not completely.

If you change pad compound, you have to hone the rotors to remove the previous pad type bonding material (otherwise, break-in cannot happen, and different compound result in unpredictable results and braking performance). If you keep using the same pads, and the rotors don't have pronounced grooves, it's ok to skip resurfacing.

Resurfacing a rotor cost money, removes life from the rotor, and may very well cost more "per miles of remaining life" than outright changing the rotor. Most people have to change rotors the first time on their own dime around 70k, at which point the rotors are done, or so close that it makes no sense to pay the cost of resurfacing for so little use left in them.

[CALWATERBOY]

Originally Posted by Meeni

Not completely.

If you change pad compound, you have to hone the rotors to remove the previous pad type bonding material (otherwise, break-in cannot happen, and different compound result in unpredictable results and braking performance). If you keep using the same pads, and the rotors don't have pronounced grooves, it's ok to skip resurfacing.

Resurfacing a rotor cost money, removes life from the rotor, and may very well cost more "per miles of remaining life" than outright changing the rotor. Most people have to change rotors the first time on their own dime around 70k, at which point the rotors are done, or so close that it makes no sense to pay the cost of resurfacing for so little use left in them.

Well, true, but a little fine grit / garnet paper'll take old pad material off.

[Meeni]

I have been told that using regular sandpaper is wrong (it contaminates the rotor with its own residuals). I have done it anyway without adverse effect but well.

[DetectiveLoki]

What I did was used the CRC brake cleaner. It's a spray that you spray onto the rotor to remove any residual substances.