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It's not usually the heat itself that warps rotors, it's uneven cooling. If you get the brakes hot and keep driving the rotors will cool evenly and they'll be fine. If you get the brakes really hot and then park the car right away you can warp your rotors. The portion of the rotors that stay covered by the brake pads cool at a much slower rate than the rest of the rotor that is exposed to the air. This is what causes them to warp.
I did repeated (stupidly again I followed the forum's advice which was wrong for OE brakes, maybe correct for track setups) 80-0 stops, when I did my BMW brakes with OE, pads/rotors. It was probably 8X. Nothing warped. Not only did they not get a chance to cool, they turned red.
The one guy who cut through the BS and was logical. He said, when you buy a brand new BMW from the dealership, does the SA tell you to get on the highway first thing, and do 8 80-0 stops and turn the rotors red? Of course they don't, they tell you to go easy for 1000 km. And if you don't believe that, then you will see there's a cardboard tag in the box of pads that hangs on the rearview, intended for the tech to place, and it says to go easy for 1000 km. Boy did I feel like an idiot, but knock on wood 2 yrs. later nothing happened. I'm still of the camp that it's runout and uneven wear, not heat. But again, in reality, we can treat the symptom and disagree on the root cause.
Most brake kits come with a pad bedding procedure. Some manufacturers apply a "break in coating" to the pad surface and these have specific procedures. I've used a bunch of Powerstop kits on various vehicles and they have a procedure to follow printed inside the box.
I just installed these on my Mini today.
Does anyone know if Lexus has a procedure for their brakes? I just ordered OEM pads, rotors and caliper bolts. I hope to be installing them this weekend.
Does anyone know if Lexus has a procedure for their brakes? I just ordered OEM pads, rotors and caliper bolts. I hope to be installing them this weekend.
Service manual should have it. You could ask the member rkw77080.
If the rotors are warped and you can do your own brakes I suggest buying a cheap Chinese dial indicator and micrometer to check the axial runout and thickness variation of your existing rotors. If it’s over 0.002” axial runout and over around 0.001” thickness variation then yes your rotors are warped. If not you can take your parts back and start looking somewhere else.
Oh no, please be logical. When you buy a brand new car, has anybody told you to do repeated 80-0 stops until your rotors change colors? This has been kicked around the BMW forum and you have to understand, a good % of the guys take their cars on tracks. And also use some logic as well, we have ceramic pads on the Lexus. BMWs have semi metallic and they do bite into the rotors, which result in much better stopping, but tons of dust and rotors wear.
One point that was well taken on the BMW forum. One of the articles that continues to be hyperlinked to as far as the necessity of bedding the brakes? The article is 30+ years old and the person who wrote it passed away.
My takeaway is that unless you have a track setup? Go easy on new brakes, OE or aftermarket, especially if ceramic pads. Now that I've said it, I'm sure people will do the opposite, maybe claim their rotors are warped (they don't but ok), but to each his own.
Service manual should have it. You could ask the member rkw77080.
If the rotors are warped and you can do your own brakes I suggest buying a cheap Chinese dial indicator and micrometer to check the axial runout and thickness variation of your existing rotors. If it’s over 0.002” axial runout and over around 0.001” thickness variation then yes your rotors are warped. If not you can take your parts back and start looking somewhere else.
Cheap and Chinese no longer go hand in hand (have you priced say a washer machine lately?). Maybe buy a cheap American one.
Here's the flip side from maybe a less "performance" perspective. It wants 20 complete stops from 30 mph. Also states moderate or light pressure, and no panic stops.
I've done it both ways, aggressively on the BMW which was stupid. I'm not too proud to admit when I do stupid things. There might be someone out there who as a result doesn't do a stupid thing. Luckily, nothing happened, and it was 2 yrs ago. But on my wife's which got 4 new rotors in July, and the LS which got 2 new rear rotors Labor Day, I went gently. The latter is the way to go. Even BMW recommends 1000km of going easy.
I don't think the brand of disc pads and rotors have any substantial impact on the distance to stop the car. Here's why. I'm assuming that all cars that we are talking about have aiti-skid brake systems. In that case, all the cars have the ability to apply the braking to the point when the wheel skids. If you were to go beyond that point the tire is locked up and you loose braking altogether. So a person that stomps on the brakes and holds the pedal down has put the system in it's maximum capacity for braking. Having different pads or rotors will make no difference at that point. Braking distance will be the same.
The real difference comes in the ability to recover and be able to brake successively on rapid order. This is where generated heat begins to make a difference in the pads and rotors. People who race their cars are very interested in maximizing the braking over a race track. I suppose that driving down a long, steep mountain might be a reason for better heat capability.
For straight line braking on flat ground I don't think the anti-skid braking system will allow a person to detect a difference in braking with different brand pads and rotors.s
Here's the flip side from maybe a less "performance" perspective. It wants 20 complete stops from 30 mph. Also states moderate or light pressure, and no panic stops. https://www.wagnerbrake.com/technica.../break-in.html
Did you read the print at the bottom of that article?
" The content contained in this article is for entertainment and informational purposes only and should not be used in lieu of seeking professional advice from a certified technician or mechanic. "
Not saying it's wrong just thought that was kinda funny. I need to call that Lexus dealer I bought my pads and rotors from....Bell in Arizona, maybe they can tell me the Lexus procedure.
[edit] Called Bell parts dept and they said the techs do a hard stop 3 to 5 times and that's it.
I have 3 cars on which within the last 2 years I have replaced rotors. Car #1, I did repeated 80-0 stops and the rotors got so hot they changed color, and it smelled like burning.
The other two cars I went gently when the brakes were new, didn't think about it that much, but never did a panic stop.
All 3 cars have no pulsation, today. Maybe that's how it's supposed to be, maybe not. No need to overthink it, the choice is up to the owner of the car really, nothing more, nothing less...ok I'm out. Really. Until I'm back...
I really think that easing in is best, but if you do bed the brakes, I doubt anything bad would happen.
Yeah I think I'm gonna do what the Lexus techs said, just a light bed in with a few stops, nothing aggressive like what was suggested for the Brembo brakes I put on. It was ridiculous.
