keep or replace rotors
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MBWorld Fanatic!
Joined: Mar 2014
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From: West Central Florida
2011 E550 P2 4M Sedan
keep or replace rotors
So I will be getting new front and rear pads done in the next week or so. The dealer had recommended replacing the rotors on all 4 corners regardless of condition at the same time. But I plan on using an indy and they will check the condition of the rotors first. Currently I don't sense any vibrations while braking in the wheel or in the seat. Other than measuring them with a caliper, can you gauge the condition by feel?
On the front rotors, there is a small lip at the outer edge and there seems to be a slope coming off the center indicating they've gotten some wear. The surface between the center and edge seems smooth. On the rear, there is no perceptible lip on the outer edge or slope coming off the center. Just trying to have an idea of what to expect before I bring them in.
On the front rotors, there is a small lip at the outer edge and there seems to be a slope coming off the center indicating they've gotten some wear. The surface between the center and edge seems smooth. On the rear, there is no perceptible lip on the outer edge or slope coming off the center. Just trying to have an idea of what to expect before I bring them in.
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From: V E G A S
1922 Ford Model T / no OBD
... they always do. Rotors are "free money flow" for the shops as they don't require much additional work to the pads replacement, while generate income not only on labor, but also on part markup.
This way shop can make $500 in less than 1 hr.
For me rotors are lifetime item as they seem to last at least 400,000 miles.
The min thickens is always stamped on them. Look at smaller cylindrical part outside where rear have E-brake shoes.
Big lips develop with less than 50% of wear, so I grind them at this point.
This way shop can make $500 in less than 1 hr.
For me rotors are lifetime item as they seem to last at least 400,000 miles.
The min thickens is always stamped on them. Look at smaller cylindrical part outside where rear have E-brake shoes.
Big lips develop with less than 50% of wear, so I grind them at this point.
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I concur with everyone, Fisch. Measure to be sure, and if good maybe a quick resurface and good to go. If you start with a clean surface the pads will have a better chance of transferring material to the rotor and bed properly, so you can continue with your smooth braking.
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Joined: May 2007
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From: S JERSEY/PHILLY
2007 mercedes e63, 2006 bmw 530 Xi with Mtech kit , 2005 ford expedition
The only bad thing is if the rotors are slightly worn when u slap new pads on you mite get sum vibration... That was my case When I did my brake job on my e63 I had the same outer lip on rotors..the Mechanic mentioned thst I mite get a lil vibration when the new pads go on and that's exactly what happened
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From: South Florida
2010 E63 AMG, 2003 E500
If you did decide to replace your rotors you may want to consider upgrading to slotted discs. From my experience and research it seems they provide many of the benefits of cross drilling without the potential for cracking.
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MBWorld Fanatic!
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From: West Central Florida
2011 E550 P2 4M Sedan
Thanks for the input everyone. I will definitely ask for a measurement because I can't see or feel the condition of the back side of the rotor. In regards to grinding, I thought the resurfacing of cross-drilled rotors like the ones on the front was a no-no due to chipping. Also, some indy shops I have talked to have to send rotors out for resurfacing so the labor cost to remove and reinstall and resurface isn't that much more than a replacement. If I was doing it myself that would be another story.
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From: V E G A S
1922 Ford Model T / no OBD
I was referring to grinding the lip, when the rotor still has lot of thickness left. MB does not have much thickness for turning the rotors, so if you have deep groves - they call for rotor replacement.
Grinding front rotors is a breeze. When you angle grinder at good angle - the grinding will start turning the rotor for even finish. Rear is more difficult.
Grinding front rotors is a breeze. When you angle grinder at good angle - the grinding will start turning the rotor for even finish. Rear is more difficult.
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Joined: Jul 2014
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From: Tucson, AZ
'20 X5 M50i; '17 Ram 3500; Golf Cart; Bikes; Scooters
The diesel has so much engine braking that the brakes are only lightly used, and could be a lifetime item.
On the other hand, my SL55 at 94K has a good sized lip on the massive rotors, 5K mile pads half worn, and will likely need the grinding you mention soon. Still above minimum thickness.
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From: Sacramento , CA
2010 e550 p2
If your rotors are smooth without any grooves or bad wear id keep them... otherwise replace them. I did my fronts over a month ago..and i replaced rotors and pads. But my rotors were bad.
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From: Sacramento , CA
2010 e550 p2
Had that happened , and that happened to be the OEM akebono pads that i used on old rotors with grooves.
waisted 100 bucks basically.
Shortly after some time it started vibrating pretty badly when applying brakes, so i went ahead and bought new pads AND rotors.
Lesson learned.
waisted 100 bucks basically.
Shortly after some time it started vibrating pretty badly when applying brakes, so i went ahead and bought new pads AND rotors.
Lesson learned.
Super Member
Joined: Oct 2013
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From: Bay Area, CA
2010 E550
I use pads and rotors from the local Mercedes dealership, so they're genuine. I've gone through like 3 sets of pads on the same rotors on my old w202 and never had a problem with vibration. I drove that old w202 for over 9 years.
I haven't had to change my pads or rotors on my w212 yet though so I can't speak to the quality of those.
I haven't had to change my pads or rotors on my w212 yet though so I can't speak to the quality of those.
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From: V E G A S
1922 Ford Model T / no OBD
Is your E250 a diesel? I just checked the brakes and pads on my 2011 E350 Bluetec diesel, and at 54K miles they were like new.
The diesel has so much engine braking that the brakes are only lightly used, and could be a lifetime item.
On the other hand, my SL55 at 94K has a good sized lip on the massive rotors, 5K mile pads half worn, and will likely need the grinding you mention soon. Still above minimum thickness.
The diesel has so much engine braking that the brakes are only lightly used, and could be a lifetime item.
On the other hand, my SL55 at 94K has a good sized lip on the massive rotors, 5K mile pads half worn, and will likely need the grinding you mention soon. Still above minimum thickness.
Anyway, I am trying to remember and in last 25 years the only rotors I had to replace was when I bought Audi for my son.
I was doing >100k miles on old brake pads, even in Fiat and last time I check Akebonos after driving 80k on them, the pads wear was in range of 20-25%.
Only exception was ML where pads lasted 60k, but most owners report 30k.
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From: West Central Florida
2011 E550 P2 4M Sedan
I was referring to grinding the lip, when the rotor still has lot of thickness left. MB does not have much thickness for turning the rotors, so if you have deep groves - they call for rotor replacement.
Grinding front rotors is a breeze. When you angle grinder at good angle - the grinding will start turning the rotor for even finish. Rear is more difficult.
Grinding front rotors is a breeze. When you angle grinder at good angle - the grinding will start turning the rotor for even finish. Rear is more difficult.
Thread Starter
MBWorld Fanatic!
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From: West Central Florida
2011 E550 P2 4M Sedan
Thread Starter
MBWorld Fanatic!
Joined: Mar 2014
Posts: 3,107
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From: West Central Florida
2011 E550 P2 4M Sedan
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From: Dallas-Ft.Worth,TX
2016 E350 Sport
fisch, as others have noted, I wouldn't replace the rotors with a pad change, unless...
1) The rotors are warped and apparent in your steering while braking (wobble).
2) The rotor thickness is near the wear minimum, as measured with a micrometer.
On my previous Mercedes, I did not replace the front rotors until I installed it's second set of pads (meaning OEM + two sets of pads) around 65,000 miles. When that set of fronts wore out, (about 95,000 miles) I replaced all four sets of pads along with all four rotors (the rears needed it at that time, only).
Your mileage may vary, depending on how much city driving (constant brake applications) you do. Looking at the pics you've posted, I doubt the rotors need to be replaced at this time. In contrast, mine were deeply grooved by the time I replaecd them. And almost without exeption, the rears will wear much less quickly than the fronts.
1) The rotors are warped and apparent in your steering while braking (wobble).
2) The rotor thickness is near the wear minimum, as measured with a micrometer.
On my previous Mercedes, I did not replace the front rotors until I installed it's second set of pads (meaning OEM + two sets of pads) around 65,000 miles. When that set of fronts wore out, (about 95,000 miles) I replaced all four sets of pads along with all four rotors (the rears needed it at that time, only).
Your mileage may vary, depending on how much city driving (constant brake applications) you do. Looking at the pics you've posted, I doubt the rotors need to be replaced at this time. In contrast, mine were deeply grooved by the time I replaecd them. And almost without exeption, the rears will wear much less quickly than the fronts.
Last edited by DFWdude; Jun 1, 2018 at 02:52 PM.
MBWorld Fanatic!
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From: V E G A S
1922 Ford Model T / no OBD
Same is with replacing axle boots on 4Matics, what can be $100 job for DIY, or $2000 charge at dealer.
With some thinking I can come with few pages of sample like this. s
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From: Southern US
2010 E550, 273 Engine: 2012 S550, 278 Engine
Why would shop want to do risky job requiring some some skills for small charge, when they can replace rotors for $500 profit and easy job?
Same is with replacing axle boots on 4Matics, what can be $100 job for DIY, or $2000 charge at dealer.
With some thinking I can come with few pages of sample like this. s
Same is with replacing axle boots on 4Matics, what can be $100 job for DIY, or $2000 charge at dealer.
With some thinking I can come with few pages of sample like this. s
Grooves on rotors normally do no harm at all. New pads will wear in to the grooves after some use of the brakes.
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From: West Central Florida
2011 E550 P2 4M Sedan
Unfortunately, I can't see the minimum thickness stamp on the rotors themselves. Perhaps you have to remove the wheel to see that or I was looking in the wrong place. At any rate, some online searching for products shows that new rotors for the E550 come with 32mm on the front and 24mm on the rear. From reading online about MB rotor thickness and some product descriptions, the service limit appears to be about 2mm (front) and 2.6mm (rear) of wear before you shouldn't use again with new pads. So the service life for the rears is longer than the fronts which get more wear naturally.
Dropped my car at the indy shop today for them to change the pads and check the rotors. They said they will measure them to check and call me about the need to replace. Before bringing the car back, the mechanic inspected the rotor condition with the wheel on. He noted that the rear rotor barely had a lip which was a good sign for reusing that rotor - measuring will backup that assumption. However, on the front rotors, while the condition looked good he said the lip was more noticeable and he showed me how it catches the end of his flashlight. He said he will check the wear on the inside of the rotor as well, but if both sides have this much lip then he expects it will measure below the service minimum.
Dropped my car at the indy shop today for them to change the pads and check the rotors. They said they will measure them to check and call me about the need to replace. Before bringing the car back, the mechanic inspected the rotor condition with the wheel on. He noted that the rear rotor barely had a lip which was a good sign for reusing that rotor - measuring will backup that assumption. However, on the front rotors, while the condition looked good he said the lip was more noticeable and he showed me how it catches the end of his flashlight. He said he will check the wear on the inside of the rotor as well, but if both sides have this much lip then he expects it will measure below the service minimum.
Thread Starter
MBWorld Fanatic!
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From: West Central Florida
2011 E550 P2 4M Sedan
Car was done after a few hours. As expected the rear rotors were fine and actually had 1.5mm left before the minimum thickness. I guess that's about 50% wear - not bad for 87k miles. Mechanic said they might need replacement when it's time for new pads. However, the front rotors did not meet the minimum specs so those were replaced. My car must just eat front rotors. According to my VMI, the original owner replaced the front pads and rotors at 38k miles. And here I am replacing those front rotors after 50k miles.
$484 plus tax for the front pads, rotors and sensor including labor. $182 plus tax for the rear pads, labor and sensor. $713 out the door in total. Better than the $1,600 the dealer wanted.
$484 plus tax for the front pads, rotors and sensor including labor. $182 plus tax for the rear pads, labor and sensor. $713 out the door in total. Better than the $1,600 the dealer wanted.
