how to "break in" new rotors?

[short1]

I've seen mentioned that you are supposed to "break in" new rotors so they are less likely to warp. What does this process involve? I'm replacing rotors again and want to do this since they always seem to get warped quickly.

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[TechnoDestructo]

I've seen mentioned that you are supposed to "break in" new rotors so they are less likely to warp. What does this process involve? I'm replacing rotors again and want to do this since they always seem to get warped quickly.

short

Google gives me this:
http://www.tirerack.com/brakes/tech/....jsp?techid=85

I've never had a problem just driving normally, though, including with my Accord. It may depend on your driving style, however. (I learned to drive in a snowy clime, so I've got a light touch on the brakes.)

[deevergote]

Most pads have their own break in process provided by the manufacturer. When replacing rotors, you should always replace the pads as well! I would follow the procedure specified by the pad manufacturer.

What brand rotors are you buying? Cheap rotors are known to warp. Brembo blanks aren't overly expensive, and they truly take a beating. I've had Brembos, slotted and drilled by an aftermarket company, that have been on my CB7 for about 100k miles. One of them even met the metal backing plate of a worn pad (my calipers are in need of rebuilding, and the inner pad wore faster than the outer... I didbn't know until it was too late!) That rotor is scored, but it never warped.

[cb7pr]

I have Brembo Blanks on my Element, and I followed a DIY on how to break them in. It consisted of driving to different speeds gradually, and then brake to a hard stop, for several rounds, then take it to highway speeds without stopping for a few mins til they cool down.

[deevergote]

Yeah, most break-in procedures require stops from various increasing speeds, and specify not to come to a complete stop. Granted, it's not very easy to not stop completely... so do it GRADUALLY when doing a break-in!

You want to heat-cycle them, as well as properly mate the pads to them to avoid glazing.

[batever]

Interesting. The moment of a full stop applies a high transient force to the rotor. I never thought of that.

[visualpoet]

I was taught to get out in the country where you wouldn't be a hazard to others, and to run the car up to between 60 mph and 80 mph, then brake hard, without locking them up until you were almost stopped, then accelerate back up to speed again, and repeat this several times, then to drive around for about 15-30 minutes without using the brakes any more than possible to let them cool off before you came to a complete stop. It tempers and hardens the rotors without forcing a "bulge" from the hot metal being pinched and stressed out of true.

[Tippey764]

I was taut that you needed to use the brakes hard when you install new rotors to remove some sort of finish from them and wear the pad onto the rotor. I was told to just drive the car around and use the brakes really hard for a few minutes and it will be good to go.

[deevergote]

I was taut that you needed to use the brakes hard when you install new rotors to remove some sort of finish from them and wear the pad onto the rotor. I was told to just drive the car around and use the brakes really hard for a few minutes and it will be good to go.

... not exactly.


The best thing to do is follow what the specific pad manufacturers say. They're all a little different.

[short1]

Hmm thanks for the input guys, I got the cheapo duralast rotors. I'm only replacing one rotor, as the caliper pins froze on that side, wore down the inner pad to nothing, which in turn gave the rotor more grooves than a record. But hopefully I can just get the other side resurfaced and wanted to have a fresh start with the pads and rotors.

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[deevergote]

It's not a good idea to replace just one rotor, unless the other is damn near brand new.

[Tippey764]

It's not a good idea to replace just one rotor, unless the other is damn near brand new.

Yeah, if you replace just one side then your car will pull twords the new rotor when you brake

[h22dude]

this shit is interesting, might sound retarded but i didnt know you had to brake in rotors. all i knew was getting the sticky stuff of with some sandpaper. thats some good info to kno

[cloudasc]

Yeah, if you replace just one side then your car will pull twords the new rotor when you brake

When I last had my front brakes serviced, it was only required for me to buy a new rotor on the passenger side, as there was not enough material to resurface within spec, so I had it replaced. After the driverside was resurfaced, and the new rotor installed on the passenger side, with new brake pads, it never pulled to one side, or towards the new rotor under any condition.

Why did I only replace one rotor and not both? Because honda pressed the rotor onto the hub, and Sears required an extra $100 in labor per rotor replacement (so they could use a slide hammer on it to get it off, and slidehammer the new one on). The car was also a daily driver, I didn't have much money, you do what you gotta do, and if something happens to my ass or car, I know Sears got some deep pockets! 2 years & 40k miles on the setup above, and no problems.

[short1]

It's not a good idea to replace just one rotor, unless the other is damn near brand new.

They were both only about 5 months old.

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