coldfire

iTrader: (1)

so i know how to bed in new brake pads, however my situation is that i have BOTH new rotors and pads.

now the bed-in procedure for both are conflicting. for the brake pads they say you shouldn't drive far before bedding them in.
but the brake rotors say to drive about 300km before doing any hard braking.

anyone have advice on how to bed them in properly?

thanks

RETed

Most manufacturers will tell you to bed brake pads with used rotors.


-Ted

rynberg

You need to quit listening to mechanic's old wives tales....read this:

http://www.stoptech.com/whitepapers/bedincontents.htm

And while you're at it:

http://www.stoptech.com/whitepapers/...rakesright.htm
http://www.stoptech.com/whitepapers/...abs_122701.htm

connor@tirerack

Actually the break in procedure for the rotors is meant to build up the heat resistance more than for bedding in the brake pads. Most manufacturers call for between 150-200 miles of light to normal braking to break in the rotors.

You should follow the brake pad bedding procedure first but continue with light breaking for at least the first 150 miles. If you don't follow the basic break in guidelines you could end up with hot spots on your rotor which will cause vibration.

As for bedding brake pads on used rotors? I have never dealt with a manufacturer that recommended bedding pads on only used rotors. In fact most, not all, recommend replacing the rotors when you replace the pads to eliminate the chance of pad contamination and future problems. All manufacturers recommend at the very minimum turning the rotors as long as the final turned thickness is thicker than the minimum specified thickness.

coldfire

iTrader: (1)

i've already read every single one of those articles actually (except for the ABS one since i don't have ABS)

unfortunately the bed-in article focuses on the pads, and the card that i got with my new rotors state LIGHT braking for about 300km.
that is why i was wondering.

anyways, if i understand this correctly, i can perform a pad bed-in right away, i just have to make sure i don't get the rotors to full operating temp?

like if i make a few hard runs from 60-10, but don't stop the car and keep the rotors relatively cool, then this should be fine?

thanks
- Aaron

DamonB

Turning the rotors accomplishes the same thing and I always do it when switching pad types to prevent what you explained.

Regardless of what you're breaking in you never want to stop the car while the rotors and pads are really hot. After doing the break in runs drive around for another 10-15 minutes using the brakes lightly to let everything cool. Pick a route that doesn't require you to stop at stoplights etc.

rynberg

I'm guessing that the card was more intended for people who don't know how to bed-in pads properly...

What is there to "break-in" on a rotor? It's a hunk of iron. The process of bedding-in the pads transfers a layer of brake dust to the rotor and then you're ready to go.

Someone please correct me if I'm wrong...

coldfire

iTrader: (1)

yes, that's true about transferring the brake dust.
but the way i see it is, since the time that hunk of iron has been manufactured, it has not seen the extreme temps of hard braking.
basic metallurgy would say something along the lines of properly "setting" the lattice of the metal through increasing heat treatment, instead of going to the max temps right away. it just seems to make sense.

also, if you are just braking lightly, is there anything bad to not bedding in the pads right away? like will it ruin the brake pads to drive lightly for a bit, and THEN bed them in?

DamonB

That's always been my understanding about bedding in rotors. How much does it really matter? I don't know.

coldfire

iTrader: (1)

it might not even be as much of a performance issue as a longevity one.

maybe properly bedding them in will make them less prone to warping or cracking, who knows.

i've also noticed that really cheap $40 rotors will become warped faster than some $100 pieces, so maybe it's more important on those cheap ones...

patfat

What about track pads. I typically drive around and just do some light breaking from 40-2mph several times. Then go do some 145-40 mph runs I have never had a problem I also never have and pad life