Warped rotors on my C300, any better options?
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From: California
2018 C300
Warped rotors on my C300, any better options?
Well, after a spirited run through the hills of Malibu, my brake rotors were warped! I've never had that happen on a car, and I've taken quite a few of them through those hills. Does anyone have any idea if anyone makes a rotor that can handle the heat cycling better than the ones Mercedes puts on there? I would prefer to be able to drive the car spiritedly from time to time without having to worry about damaging the rotors, considering it's actually a fun car for that sort of thing. Before anyone gives me too hard a time, I don't race through those curves, I probably had the car at about 9/10's for the cornering and 6/10's for braking/acceleration. Having fun but not outright abusing the car, and always between the lines.
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Thanks for the Short Story.... but frankly it was a bit short on substantive info.. like Year... Miles...is this front or rear brakes "warped" ... and exactly how you diagnosed "warped rotors.... oh, please share if your MB now MB is with/or without AMG Sport Package or Sport brakes (MB drilled rotors), or if you have standard brake system (MB flat/not-drilled rotors).
Happy to hear you have a nice drive... how much did you use the shift paddles... since using tranny for added deceleration going into a curve really "adds to" braking power..
Happy to hear you have a nice drive... how much did you use the shift paddles... since using tranny for added deceleration going into a curve really "adds to" braking power..
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From: SF Bay Area, CA
2018 C-class sedan
Rotors don’t warp. The pulsation you feel during braking is due to uneven rotor wear and uneven brake pad deposition onto the rotor. Two mechanisms of braking are abrasive and deposition. Abrasive braking is like the friction created when sand paper is rubbed against a surface. If the rotor is not centered properly within the caliper (i.e., runout), then the abrasive pad will unevenly eat away the rotor. Deposition braking is like laying rubber when you spin your tires. Brake pad material is transferred and sticks to the rotor. The rotor doesn’t warp due to high temperature into a potato chip, but rather has uneven wear and brake pad material deposition. Selecting a brake pad and rotor combination is a compromise between street driving system longevity versus race driving aggressive braking capability with increased system wear.
However, all that handwaving didn’t answer your question. Both Powertech and Brembo offer Mercedes brake pads/rotors. I don’t know if their product has any advantage for your twisty road driving over OEM. A nagging thought I constantly have is how will the car computer calibration for emergency stopping (e.g., pedestrian, frontal collision) be compromised if I change the braking system pad/rotor combination.
However, all that handwaving didn’t answer your question. Both Powertech and Brembo offer Mercedes brake pads/rotors. I don’t know if their product has any advantage for your twisty road driving over OEM. A nagging thought I constantly have is how will the car computer calibration for emergency stopping (e.g., pedestrian, frontal collision) be compromised if I change the braking system pad/rotor combination.
Thread Starter
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Joined: May 2016
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From: California
2018 C300
Thanks for the Short Story.... but frankly it was a bit short on substantive info.. like Year... Miles...is this front or rear brakes "warped" ... and exactly how you diagnosed "warped rotors.... oh, please share if your MB now MB is with/or without AMG Sport Package or Sport brakes (MB drilled rotors), or if you have standard brake system (MB flat/not-drilled rotors).
Happy to hear you have a nice drive... how much did you use the shift paddles... since using tranny for added deceleration going into a curve really "adds to" braking power..
Happy to hear you have a nice drive... how much did you use the shift paddles... since using tranny for added deceleration going into a curve really "adds to" braking power..
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Joined: Jun 2015
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From: Dutchess County, NY
2016 C300 4matic
That baffles me. I've had my original rotors on the car for 63,000 miles now with no issues (granted I have the sport package). I wonder if there's a defect with them.
That having been said, I upgraded to ceramic pads from Rock Auto back in 2017 in order to reduce the copious amounts of dust the OEM pads made. The braking effectiveness is indeed negatively affected, BUT, I will state from my own experience that it's not a major change and if you're driving carefully to begin with it won't be any issue. Also, I have had my emergency braking system actuate, just as recently as July 3rd with 4 people in the car, and I will say the car stopped as designed and did not hit the car in front of me. So i'd say if you want to swap pads and rotors then go for it. Just be safe and have fun.
That having been said, I upgraded to ceramic pads from Rock Auto back in 2017 in order to reduce the copious amounts of dust the OEM pads made. The braking effectiveness is indeed negatively affected, BUT, I will state from my own experience that it's not a major change and if you're driving carefully to begin with it won't be any issue. Also, I have had my emergency braking system actuate, just as recently as July 3rd with 4 people in the car, and I will say the car stopped as designed and did not hit the car in front of me. So i'd say if you want to swap pads and rotors then go for it. Just be safe and have fun.
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2025 GLC 300
The front rotors on my 2016 C300 warped after spending an hour or two in traffic with Distronic + on in the most aggressive setting. Rotors were warped; pads were fine and re-used. I would definitely go after-market. BTW this is the first time I've every had warped brakes too....normally I don't even have to change out pads until 80K miles, and these warped around 17k.
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W205 C250
The first installment rotors seems to last longer than replacement ones. With occasional spirited driving I was able to get ~25000 miles from original rotors and ~20000 from replacement ones. I still had original rear rotors at the point of selling the car (~55000 miles). The first thing you notice is shaky brake pedal on a higher speed. It can also shake the steering wheel as well. The only advice I can give you is to let the car to cool down after spirited driving and not park it right away. But, I've been doing it like that and was not able to get large mileage from front rotors as well. People who speak about large mileage with the same front rotors are prolly those driving on a highway a lot or not using the brakes often.
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CLA250
i have been poking around for alternative pads too ... which ones did you get from rock?
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From: Dutchess County, NY
2016 C300 4matic
Agreed, I will be purchasing one set of spare rotors to swap on and resurface them until they are both at min spec. I will say though that from my experience some shops do not like to resurface sport rotors (i.e. - drilled and slotted). You may have to shop around at different shops or ask your MB dealer directly if they will do it. The cost savings is huge though.
Last edited by RemmyZero; Aug 1, 2019 at 09:41 AM.
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I don't know where some of these "facts" are coming from - for instance MB dealers NEVER "resurface rotors" - and frankly there are very few general automotive shops that even do that anymore.
For the C300 - the brake discs are different between "standard" rotors and "Sport" or "AMG Sport Package" - fronts are drilled - rears are ventilated design..
For the C300 - the brake discs are different between "standard" rotors and "Sport" or "AMG Sport Package" - fronts are drilled - rears are ventilated design..
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W205 C250
Well I drive about 20k miles a year and 40-50% of that is easily 'stop & go' / city driving. So in some respects you're right but it definitely depends on your driving styles and how much you ride the brakes. With that said I have 63k miles on the car now, so for argument sake you could say I have ~30k miles of 'stop & go' wear on my original rotors.
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From: Dutchess County, NY
2016 C300 4matic
Maybe it's just my driving style. I will say that you can definitively feel the wear lip on my rotor if you touch it so it's likely i'll be replacing them rather soon. My plans are to swap them out in the fall and cut my old rotors to keep for the next change out. On my Infiniti I did that for a few years. I had two sets of sport rotors. One on the car and one cut and in my basement for the next brake change. I'd just rotate them out as needed.
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CLA250
So this is simply what I felt with my own senses, but the 'bite' on the ceramic pads is not as aggressive as the stock MB pads. Meaning, increased pressure is required for the same stopping force and stopping distance has increased. I will say it hasn't changed by much at all, but I clearly noticed it. I will reiterate that I don't have any concerns or apprehensions about driving with the ceramic pads. They stop the car effectively and produce nearly zero dust. It's just clear to me that they are not as aggressive as the stock pads. I am okay with this trade-off. Also, as I mentioned before, my collision avoidance system has actuated and the car stopped in time, every time. I purchased the Power Stop ceramic pads from Rock Auto. Just go down the selection chart for which C300 you have and it will show you very clearly if they're available for your car (I don't know offhand if you have the sport or not). They may have other brands available but when I bought them in 2017 it was the only choice on there.
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From: Dutchess County, NY
2016 C300 4matic
Appreciate your candid comments ... I thought I was "feeling" things when I used ceramic pads on another car and had to press the brake pedal more firmly to get similar results. Guess the auto brake system can still apply the pressure it needs even if we can't stomp on it hard enough. 8-)
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CLA250
I've had Akebono ProAct ceramic pads before on my other vehicles and felt they were superior to the OEM pads (namely my infiniti G35 and my acura TL-S) but the Mercedes OEM pads are definitely superior to the ceramics I have now. If I could change to the Akebonos I would but they don't seem to be available, per the Akebono website.
Do you happen to know the details of the ceramics you are using now?
And please forgive an odd query -- but are there markings like "EE" or "EF" or "FE" or "FF" that you can see stamped on then? Those are supposed to be DOT friction codes.
Gosh ... anyone have a PhD in brakes? 8-)
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2002 E55 AMG, 2015 Mercedes C300 4Matic
I ordered POWERSTOP Z23 Slotted and drilled rotors with carbon ceramic brake pads. the options include slotted and drilled for front only, or you can get both front and back !
The car stops on a dime and the rotors look amazing upon install. The carbon ceramic brake pads do a great job on decreasing brake dust.
They cost me about $400 to order, i installed them myself so i saved major on that!
The car stops on a dime and the rotors look amazing upon install. The carbon ceramic brake pads do a great job on decreasing brake dust.
They cost me about $400 to order, i installed them myself so i saved major on that!
Senior Member
Joined: Jun 2015
Posts: 256
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From: Dutchess County, NY
2016 C300 4matic
I also have been studying the Akebono's ... depending on who says what, either its the best thing since sliced bread, or it sucks big time. Hmmm.
Do you happen to know the details of the ceramics you are using now?
And please forgive an odd query -- but are there markings like "EE" or "EF" or "FE" or "FF" that you can see stamped on then? Those are supposed to be DOT friction codes.
Gosh ... anyone have a PhD in brakes? 8-)
Do you happen to know the details of the ceramics you are using now?
And please forgive an odd query -- but are there markings like "EE" or "EF" or "FE" or "FF" that you can see stamped on then? Those are supposed to be DOT friction codes.
Gosh ... anyone have a PhD in brakes? 8-)
Friction Code Table
So for anyone who hated high school physics, the higher the coefficient of friction (CoF for short for ease of typing) the higher the stopping power (picture CoF of 0.0 being slippery ice, and for conversation assume that a CoF of 1.0 means you are pretty much unable to move because friction is as great as the normal forces your exerting). I don't know what the pads I have now are rated at but I have my OEM MB pads in a box in my basement. When I go home this afternoon i'll look at both and report back what the code differences are. The powerstop website alludes that the ceramic pads are code FF, which is very good in the scale of stopping power.
Last edited by RemmyZero; Aug 9, 2019 at 07:20 AM.
Junior Member
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CLA250
I ordered POWERSTOP Z23 Slotted and drilled rotors with carbon ceramic brake pads. the options include slotted and drilled for front only, or you can get both front and back !
The car stops on a dime and the rotors look amazing upon install. The carbon ceramic brake pads do a great job on decreasing brake dust.
They cost me about $400 to order, i installed them myself so i saved major on that!
The car stops on a dime and the rotors look amazing upon install. The carbon ceramic brake pads do a great job on decreasing brake dust.
They cost me about $400 to order, i installed them myself so i saved major on that!
So good to hear some real world feedback. 8-)
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CLA250
So for reference here's a table of the DOT codes that I found which actually has the coefficients of friction listed:
Friction Code Table
So for anyone who hated high school physics, the higher the coefficient of friction (CoF for short for ease of typing) the higher the stopping power (picture CoF of 0.0 being slippery ice, and for conversation assume that a CoF of 1.0 means you are pretty much unable to move because friction is as great as the normal forces your exerting). I don't know what the pads I have now are rated at but I have my OEM MB pads in a box in my basement. When I go home this afternoon i'll look at both and report back what the code differences are. The powerstop website alludes that the ceramic pads are code FF, which is very good in the scale of stopping power.
Friction Code Table
So for anyone who hated high school physics, the higher the coefficient of friction (CoF for short for ease of typing) the higher the stopping power (picture CoF of 0.0 being slippery ice, and for conversation assume that a CoF of 1.0 means you are pretty much unable to move because friction is as great as the normal forces your exerting). I don't know what the pads I have now are rated at but I have my OEM MB pads in a box in my basement. When I go home this afternoon i'll look at both and report back what the code differences are. The powerstop website alludes that the ceramic pads are code FF, which is very good in the scale of stopping power.
If your ceramics are powerstops and they are FF, that is indeed pretty good.
As for the oems, some ferodos I have seen have FF stamped on them too?
FE is surprising cuz that could imply the pad materials give up a tad at higher temps which would lead to the "warped" braking surface thing by creating those high spots on the rotor surface via unplanned deposits from their material dissociation ... but that's just a wild and crazy guess cuz high school phaziks (as my german teacher would speak it) was eons ago! >;-)
