When to change rotors
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Newbie
Joined: Jul 2006
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From: Seattle, WA
2017 GLC43 AMG
When to change rotors
I just got the "brake wear" message on my 2005 c230k, so I took my car to a local brake shop. I was told that I need to change my rotors as well as my brake pads... My first thoughts were that he's trying to make a few more bucks off of me, so I told him, "no way, just change the pads". Instead of agreeing, he refused to change the pads without changing the rotors as well - so I said I have to think about it (given the $700 price tag).
There are multiple light grooves all around the rotor - I've attached 2 pictures. The grooves are a bit more visible in person than in the pictures, and when you run your finger over them, you can definitely feel the waves, but they are not deep at all.
Do I really need to replace these rotors? Also, this is a lease that is ending in 6 months - If I take the chance of just changing the pads, will I be forced to replace them when I go to turn in the car after inspection?
Thanks in advance.
There are multiple light grooves all around the rotor - I've attached 2 pictures. The grooves are a bit more visible in person than in the pictures, and when you run your finger over them, you can definitely feel the waves, but they are not deep at all.
Do I really need to replace these rotors? Also, this is a lease that is ending in 6 months - If I take the chance of just changing the pads, will I be forced to replace them when I go to turn in the car after inspection?
Thanks in advance.
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A box on 4 wheels
Usually they measure the thickness of the rotor to decide whether it should be changed or not. Also another thing is if the gooves are really wavy or "warped" they need to be changed as well. Looking at the picture, I say your rotors are fine.
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From: SoCal
F10
you forgot to mention your mileage, i have about 50000 miles and i'm ready for my first rotor replacement. I changed the pads (only) when the car had about 30000 miles. Looks like your rotor is fine, perhaps just change the pads. BTW, the pads are easy to replace. Pads cost about $90 for the entire front. Sensors are $7. Expect to pay $50-100 for labor. Goodluck.
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Midnight Blue 2004.5 C230 Kompressor Sport Sedan. 2002 w210 E320, 2009 w211 E350 Sport
For cross drilled or slotted rotors it is recommended every other pad change. How many times have you changed the pads before?
Another thing is, $700 is over priced for just front. I hope that quote was for front and rear.
Another thing is, $700 is over priced for just front. I hope that quote was for front and rear.
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From: Orange County
2005 C Wagon (No snickering please!)
The rotor in the photo is toast. The concentric rings are most likely from the backing plate scratching the brake rotor surface. In the past, resurfacing the rotor in the workshop was permissible. Rotors were manufactured to be thicker so some machining could be done. Now the rotors are machined to a tighter specification than is practical to obtain with workshop brake lathes.
For safety every brake rotor is marked with a minimum thickness specification. If the rotor is less than this number, you risk brake failure because heat could not be properly managed by the rotor. This can result in serious injury or death. The rotor must be replaced. If the rotor is even close to minimum thickness when measured, it should not be placed back in service.
Rotors are available from other vendors than Mercedes. Zimmerman, Brembo, and ATE come to mind. Pelicanparts.com is a source where you can check prices. I understand you don't want to pay more for rotors on a car soon to be returned. Remember though that it is your body riding around in the car for the next six months, don't risk becoming a carcas because of a few dollars.
$ 700 for front brakes seems a bit steep. I bought pads and rotors for my car recently for $ 180. It only took an hour, but I do have a decent jack and air tools.
For safety every brake rotor is marked with a minimum thickness specification. If the rotor is less than this number, you risk brake failure because heat could not be properly managed by the rotor. This can result in serious injury or death. The rotor must be replaced. If the rotor is even close to minimum thickness when measured, it should not be placed back in service.
Rotors are available from other vendors than Mercedes. Zimmerman, Brembo, and ATE come to mind. Pelicanparts.com is a source where you can check prices. I understand you don't want to pay more for rotors on a car soon to be returned. Remember though that it is your body riding around in the car for the next six months, don't risk becoming a carcas because of a few dollars.
$ 700 for front brakes seems a bit steep. I bought pads and rotors for my car recently for $ 180. It only took an hour, but I do have a decent jack and air tools.
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From: Illinois, Indiana
2005 C230 Sedan 6spd
My mechanic, who is also a good friend of my told me I need to change the rotors when I went to change my pads for both front and back. Btw, I also changed my pads because the dashboard shows "Brake Wear Service". At first I was just as skeptical as you, but after he told me to bring my own rotors, I was less worried, since he wasn't making any profits off parts. I'm not exactly sure what I'm suppose to be looking for, as far as a worn out rotor goes, but I believed he said something about the thickness of the rotors, and my rotors should be replaced.
My front pads were completely shot ( I had like 1% left!!), I think I drove another 500 miles after the warning light first appeared. My rear still had a good 25% or so left, but I went ahead and change both front and back with EBC pads and rotors. This all happened when the car has around 55k miles on it.
He charged me $100 for about 2.5 hours of installation for rotors and pads and brake fluid. (I brought all the parts myself) Which was pretty reasonable.
I guess the best thing you can do is to get a 2nd opinion from a different mechanic like many others have already said.
My front pads were completely shot ( I had like 1% left!!), I think I drove another 500 miles after the warning light first appeared. My rear still had a good 25% or so left, but I went ahead and change both front and back with EBC pads and rotors. This all happened when the car has around 55k miles on it.
He charged me $100 for about 2.5 hours of installation for rotors and pads and brake fluid. (I brought all the parts myself) Which was pretty reasonable.
I guess the best thing you can do is to get a 2nd opinion from a different mechanic like many others have already said.
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From: Irvine, CA
2013 E350 Bluetec, 2008 Audi S4 Avant, 2011 VW Golf TDI, 2015 Audi S3, 2020 GLB250
I think they look fine. Mine were much worse at only 20,000 miles. See thread here: https://mbworld.org/forums/c-class-w203/164193-concentric-ridges-grooves-brake-rotor.html
I replaced my rotors when I replaced the brake pad the first time. Bought Zimmerman rotors online and got pads from local auto parts store. Total parts cost me around 250.00, did the work myself. It was the first time I've ever changed brakes, and it wasn't that hard at all. Took about 2 hours for me to do the fronts, and that's 1-1/2 hours on the left side first, then 30 minutes on the right side.
I replaced my rotors when I replaced the brake pad the first time. Bought Zimmerman rotors online and got pads from local auto parts store. Total parts cost me around 250.00, did the work myself. It was the first time I've ever changed brakes, and it wasn't that hard at all. Took about 2 hours for me to do the fronts, and that's 1-1/2 hours on the left side first, then 30 minutes on the right side.
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From: Worcester, MA
15' CLS400
The dealer will always make you buy new rotors. And if your using the MB pads which are very soft you don't need to buy new rotors. However, if you are going to use your old rotors you should have them cut buy some other garage (this is usually pretty cheap). The rotors can only be cut once since a second cut would make them too thin.
I would not recommend getting the brakes done at MB. At the same time I would also not recommed getting them done at someplace like Midas (LOL). Here's what to do: Go to MB and buy the rotors (the price is pretty decent), then go online and buy some Porterfield brake pads (absolutely no more brake dust). Then either do it yourself or bring it to a local garage and have them done.
I would not recommend getting the brakes done at MB. At the same time I would also not recommed getting them done at someplace like Midas (LOL). Here's what to do: Go to MB and buy the rotors (the price is pretty decent), then go online and buy some Porterfield brake pads (absolutely no more brake dust). Then either do it yourself or bring it to a local garage and have them done.
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2002 C230 Coupe
/agree
People looking at a picture alone and saying a rotor is fine are making a judgment they cannot make. Rotor thickness is key, because that determines the heat carrying capacity of the rotors. The rotors thin over time (not as fast as the pads, but it does happen). Even if you were to get the rotors "turned" so the faces are machined flat, you may be below the minimum spec for thickness, which will result in quickly warped rotors.
(Note that the size of the lip on the outer edge of your rotors indicates to me that they may indeed be too thin. When they are new, there is no lip there, so that shows you how much material has been lost.)
While Techsuperstar wrote the pads are soft, I have heard that the MB rotors are also soft. Using OEM pads and rotors, you should expect to change rotors with every other pad change. I didn't' like this, so I bought an aftermarket pad/rotor kit. This kit (front/rear pads, front/rear slotted rotors, front/rear stainless braided brake lines) cost me $600 in parts from StopTech, and I've been happy with it.
If you cannot install the parts yourself, I'd expect to pay about 2-3 hours of labor for front/rear pads and rotors. But it's an easy job, so if you've done similar work I would recommend buying parts and doing it yourself.
People looking at a picture alone and saying a rotor is fine are making a judgment they cannot make. Rotor thickness is key, because that determines the heat carrying capacity of the rotors. The rotors thin over time (not as fast as the pads, but it does happen). Even if you were to get the rotors "turned" so the faces are machined flat, you may be below the minimum spec for thickness, which will result in quickly warped rotors.
(Note that the size of the lip on the outer edge of your rotors indicates to me that they may indeed be too thin. When they are new, there is no lip there, so that shows you how much material has been lost.)
While Techsuperstar wrote the pads are soft, I have heard that the MB rotors are also soft. Using OEM pads and rotors, you should expect to change rotors with every other pad change. I didn't' like this, so I bought an aftermarket pad/rotor kit. This kit (front/rear pads, front/rear slotted rotors, front/rear stainless braided brake lines) cost me $600 in parts from StopTech, and I've been happy with it.
If you cannot install the parts yourself, I'd expect to pay about 2-3 hours of labor for front/rear pads and rotors. But it's an easy job, so if you've done similar work I would recommend buying parts and doing it yourself.
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Joined: Jul 2006
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From: Seattle, WA
2017 GLC43 AMG
I think they look fine. Mine were much worse at only 20,000 miles. See thread here: https://mbworld.org/forums/showthread.php?t=164193
I replaced my rotors when I replaced the brake pad the first time. Bought Zimmerman rotors online and got pads from local auto parts store. Total parts cost me around 250.00, did the work myself. It was the first time I've ever changed brakes, and it wasn't that hard at all. Took about 2 hours for me to do the fronts, and that's 1-1/2 hours on the left side first, then 30 minutes on the right side.
I replaced my rotors when I replaced the brake pad the first time. Bought Zimmerman rotors online and got pads from local auto parts store. Total parts cost me around 250.00, did the work myself. It was the first time I've ever changed brakes, and it wasn't that hard at all. Took about 2 hours for me to do the fronts, and that's 1-1/2 hours on the left side first, then 30 minutes on the right side.
To answer some of the questions:
- This is the first time I am changing pads
- I have 25,000 miles on the car
- Yes, the local brake shop wanted $700 for just front pads & rotors
- This is my wife's car and she's not an aggressive driver
I guess the general consensus is to replace them. I don't think I want to take the chance with machining them and then having a different problem later - I rather just buy the parts and do it myself.
Anyone recommend a good place to buy online? I was going to go with buymbparts.com, but total for pads and rotors is around $300 - a few of you mentioned that you did it for less. Moviela?
Thanks everyone for your help and suggestions.
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From: Seattle, WA
2017 GLC43 AMG
Another reason why I am so surprised that I have to change the disks on this car is because my 2001 CLK didn't need disks OR pads during the 5 years/50,000 miles that I had it...
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2002 C230K Coupe
Listen to Moviela and don't risk your life for few bucks. I didn't change rear rotors on my previous car and one day it decided to not stop at a red light. 
Lucky me, the front brakes and rotors were brand new and stopped car after pumping brakes coupla times.
To me your rotors look worn as I can see the lip. I spoke to two mechanics and both told me that if you can see a lip that deep on an MB rotor, it is time to change it.
But $700 is very very steep for only front brakes and rotors. I got it done at a local mechanic for $300 for Rotors, Brake Pads and Sensors. He charges $60and hour, so a bit cheap. An MB specialist who charges $90 an hour quoted $350 for the same job. So you see, OEM parts seem to be around 180 and labour varies. For drilled rotors it may be a bit more but definitely not double the cost.
Lucky me, the front brakes and rotors were brand new and stopped car after pumping brakes coupla times.To me your rotors look worn as I can see the lip. I spoke to two mechanics and both told me that if you can see a lip that deep on an MB rotor, it is time to change it.
But $700 is very very steep for only front brakes and rotors. I got it done at a local mechanic for $300 for Rotors, Brake Pads and Sensors. He charges $60and hour, so a bit cheap. An MB specialist who charges $90 an hour quoted $350 for the same job. So you see, OEM parts seem to be around 180 and labour varies. For drilled rotors it may be a bit more but definitely not double the cost.
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From: West Los Angeles
Midnight Blue 2004.5 C230 Kompressor Sport Sedan. 2002 w210 E320, 2009 w211 E350 Sport
Not for cross-drilled or slotted rotors.
Cross-drilled/Slotted rotors are made to prevent rust and allow for the brakes to breath better to increase performance. When you turn a rotor it thins out the metal, so in theory, if you turn cross-drilled or slotted rotors, it causes the integrity of the rotor to decrease, thus making it unsafe.
Cross-drilled/Slotted rotors are made to prevent rust and allow for the brakes to breath better to increase performance. When you turn a rotor it thins out the metal, so in theory, if you turn cross-drilled or slotted rotors, it causes the integrity of the rotor to decrease, thus making it unsafe.
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For regular blanks its possible to have them turned or machined if they are within tolerable measurements. But for cross drilled/slotted rotors they are not recommended as most shops won't even touch them. Its sorta like shaving a cookie cutter.
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1959 220S / 1979 230 G / 2002 A210 AMG / 2003 C320 SC / 2004.5 C320 SS / 2005 ML350 SE / 2008 smart
I would not recommend getting the brakes done at MB. At the same time I would also not recommed getting them done at someplace like Midas (LOL). Here's what to do: Go to MB and buy the rotors (the price is pretty decent), then go online and buy some Porterfield brake pads (absolutely no more brake dust). Then either do it yourself or bring it to a local garage and have them done.
+ StopTech ss braided lines too !
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From: Seattle, WA
2017 GLC43 AMG
Just wanted to thank everyone for their opinion. I have ordered new pads and Zimmermann rotors from buymbparts.com. I'll try to take some pictures and post them during the install.
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From: Orange County
2005 C Wagon (No snickering please!)
I looked at Pelicanparts.com, for a 2006 C230 sport (code 949) 203.052- the disc's (203 421 12 13) are 116.25 ea and the pads (004 420 51 20) are 113.50 front set. Genuine Mercedes. You need two sensors (211 540 17 17) at $ 5.75 ea. made by PEX. Just tossing this in for anyone else who might need some brakes.
Last edited by Moviela; Aug 9, 2007 at 05:41 PM.
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because like moviela said those looked toast. if you had decided to change just the pads you may ended with what dealer charge you for brake change when you return the car which will end up costing you more.
