[hkj]

Anyone have any info on this?

Last time I took my car in for service the dealership replace the brake pads, but not rotors. I couldn't find any schedule on when the rotors need to be replaced, so if anyone can share some info it'd be much appreciated.

-hkj

[!Xoible]

u shouldnt really change them unless ur running without pads for a while and rubbing metal on metal until they're messed up.

it's not right to change rotors with brake pads... shouldnt happen... if anything, if u go metal on metal u can most likely resurface

[hkj]

So these rotors are "life time" parts too? much like transmission fluid on our cars?

-hkj

[!Xoible]

well they will wear out eventually... but maybe after 5 or 10 years of running the car.. should be over 100k miles.
again, unless ur rubbing metal on metal, they you *may* be able to resurface, if not u have to replace.

but i dont think that's covered by bmw warrant, u have to pay for it i think

[LOLrance]

Originally Posted by mantis

u shouldnt really change them unless ur running without pads for a while and rubbing metal on metal until they're messed up.

it's not right to change rotors with brake pads... shouldnt happen... if anything, if u go metal on metal u can most likely resurface

+1.

Either that, or you warp your rotors. If you track your car, you should definetly be careful of warping your rotors. After yoru session, DO NOT put your e-brake on. Just put a block behind the tire so the car will not roll.

[wj4]

I've had my rotors replaced at around 5K. My reason was that there was pulsing when I would brake lightly from higher speed, 65-80 MPH. They also replaced my pads.

I wouldn't worry about replacing the rotors unless you can feel the pulsing from the steering wheel. It will eventually happen, but whether if it's sooner or later, that depends on your driving behavior.

PS since you got new pads on now, I'd look at bedding them in.

http://www.zeckhausen.com/bedding_in_brakes.htm

[bmwmike]

From my experience my rotors have never been lifetime parts. Someone recently pointed out to me how my pads are wearing my rotors down and at a certain point i will need to replace my rotors from wear. I haven't replaced my pads yet but expect by the time they need replacing i'll have to replace the rotors as well. On my previous BMW i had to replace the rotors after 3 years from wear.

[CokerRat]

Check the StopTech website and their white papers -- tons of good usable info over there. If your rotors are worn down to a certain minimum thickness then yes you should replace them. However it is far less frequent than with pads.

People that track their cars seriously tend to get around 8 sets of pads to 1 set of rotors. In most cases with track cars its not the thickness but developing hairline cracks that warrant replacement.

For a street car that sees minimal track time, your rotors ought to last you 10+ years.

[hkj]

Thanks for the info guys! Much appreciated!

-hkj

[ENINTY]

Rotors have a minimum thickness spec stamped either on the edge or on the "hat" (where the lug holes are) that tells what the minimum thickness of the rotor can be.

[txusa03]

Just remember, any parts on a car that moves and creates friction will eventually wear out and have to be replaced. It all depends on the situation and the material. My rear rotors look like they never been used that much, I run my finger on the outside edge and I can barely feel a lip with 50K, my front has a more noticible lip on the outside edge of the rotor. Everything on the brake is still factory and has not been replaced/changed.

[smellthebeans]

Originally Posted by ENINTY

Rotors have a minimum thickness spec stamped either on the edge or on the "hat" (where the lug holes are) that tells what the minimum thickness of the rotor can be.

Excellent! Just the information I was looking for.

BMW does not recomend that rotors be "turned". Each brake job on my car has called for new rotors, to the best of my knowledge. I am at 72K miles.

[srv2790]

everytime your key reader tells the dealer your brakes are due the tech "always" checks the rotor thickness. then if they are under spec they will be replaced. it is hard to get a dealer to change them if they are not underspec because bmwna will charge them back if the replacement was unneeded. unless they are warped or something of that sort

[SoCalTech]

As stated; When we replace brake pads, we check the thickness of the rotors. If they are under, they get replaced. They usually are needed every other pad change. They are not lifetime, and do wear out.

[SineQuaNon]

I had my 2 front rotors replaced at 45k on my 335. Rears are still fine.

[ehhhwik]

Originally Posted by SoCalTech

As stated; When we replace brake pads, we check the thickness of the rotors. If they are under, they get replaced. They usually are needed every other pad change. They are not lifetime, and do wear out.

thats what my friend who is a BMW tech told me too, change the rotors on every 2nd pad change...

[ENINTY]

When rotors were less expensive I would replace the rotors and pads at the same time. Brake work is really easy, so the savings I get from a DIY pays for new rotors.

I've experienced that the old rotors get near the minimum thickness about 3/4through the 2nd set of pads and some times warp before the 2nd set of pads are used up. The rotors for the E9x seem rather expensive.

[blue2fire]

Originally Posted by hkj

So these rotors are "life time" parts too? much like transmission fluid on our cars?

-hkj

Not unless they are Carbon Ceramic