Mercedes Benz C300 W205 rear brake pad replacement and reset 

You know a few people have mentioned that, and its funny you say that, as throughout my career many supervisors of mine had said I should have been a teacher !!! Thanks for the wonderful comment ;) You made my day :)

Thanks brother, I try to keep them all to the point !!!! Thank you for the great comment and enjoy your weekend :)

Hi there!!! Thanks so much for the great comment, it means a lot to me. I do post every week, all varied automotive content so you never know what you will see next :) thanks again for the great comment and glad I was able to help out :)

Thanks soo much for the comment. It only takes a second to comment, and it makes the creator feel great!!!! It's comments like yours that keep driving me to do better and better. Thanks Brother!!!!

Thanks soo much for the comment brother!!! I do use that feature on all of my videos. The editing takes a long time and that's why most guys probably don't use it. I actually enjoy the editing and try to "spice" up the videos as well. Thanks again :)

Thanks brother, hard to grow a small channel so I'm doing my best !!!!! I really appreciate the comment. Thanks!!

Thanks so much for the great comment !!! I do appreciate it :)

Hey thanks so much for the reply. Those are two really great point that I did not know. I’m actually going to jot them down. I have a running list of little tricks for different vehicles and I did not know this. Thanks so much for sharing. I do appreciate it :)

You’re a life saver!!!!

Ohh man!!!!! 900 bucks for a service is absolutely crazy!!!! They could have at least included new pads, but even then 900 is crazy expensive. Especially on this car, where you don't need a scanner to do the brake reset. As you saw by the video there is really not much to it. The other thing I have found over the years is that Mercedes Benz brakes don't rust up like the Japanese vehicles, they must have a better quality steel. They just don't seize up as much. Glad you liked the vid :) Thanks for the comment and if you need anything else just let me know :)

Thank you for the great comment !! Much appreciated :)

@@GarageKing 🙏👍

Thanks for the info, I always thought that once the plastic wore through and exposed the wire, the wire grounded to the rotor causing the light. The open loop is a great idea. I was not sure about the sensor having to be connected to enter service mode so thanks for that clarification. I did learn something today :) Have a great weekend :)

You have a good weekend too. I just ran by MB and grabbed the pads and sensor so that's what I'm going to be doing for a much smaller part of my weekend thanks to you!

Thanks soo much for the great comment :) Its comments like this that keep me going. Thank you :)

Thanks for the comment, appreciate it and glad the vid helped you out!!!

@@GarageKing yeah it was great, please do some more on the same vehicle if you get round to it! With lock down I'm finding a I have a little more time on my hands!

@@vodyssey80 Sounds Good :) I do have some more footage of this MB, I just have to edit it and then post it. I try to get out one video per week and vary the vids. Today I posted a Toyota one. I'll do my best. Thanks buddy :)

@@vodyssey80 Vid tomorrow will be MB W205 :)

@@GarageKing Brilliant! Thanks for the nod, look forward to checking it out! Annoyingly the answer call button on the steering wheel on mine has stopped working so it stops me getting into service mode! Very frustrating times!

Thanks brother!!! Really appreciate the comment :) Most people just watch the vid and move on so thanks for taking the time to do so. Thanks again :)

Thanks soo much for the great comment !!!

Thank you !!! I do appreciate the comment :)

Thanks I appreciate it, they actually time quite some time to produce.

Thank you for the great comment, and always more to come !!

Hi there, the 2018 should be the same as its a W205, I'm not sure why it would say active brake assist function limited. That sounds like something else, and may not be related to the brake job. I would take it back to the mechanic to see what he says.

Thanks soo much, as a car enthusiast, I'm really not partial to just one make. I must say I do favour the performance cars!!!!

Great question, for me I left it on, as I was afraid something was going to happen, then the car just turned off, (went into powersaving mode) so when It came time to put the brakes back into the operational position, I pushed the start button to turn on the car and then pressed the button to refit the calipers and all went well. So to answer your question I think you are safe to turn the ignition off.

Hi buddy, most are the push type. You can tell if you look at the caliper piston face. If its flat and has a design in it (like and X or holes) then its a twist type. If the piston looks hollow (like if you took it out you could use it as a cup then its a push type. Some rear brakes have shoes on the inside of the rotor, and those calipers are twist type. The MB is a little different as it has an electric brake, the electric brake is twisting inside and that's why I could push it in with the tool. Also ALL front brakes are push in pistons and that's where that tool really comes in handy as the front pistons are bigger and harder to push in. If you use big pliers the piston is pushed on an angle and its not good. That is my go to tool!!!! I did put a link in the video description for the tool if you wish. Once you use it once its worth its weight in gold!!! Any other questions just let me know!!! Thanks!!

You are right I did replace the front and back, they are two different videos so people could choose if they wanted to see the front brakes or the rear brakes. It was actually the rear brakes that was causing the light to come on. The front brake sensor was still ok, but it was getting very close so I changed the front brakes. But to answer your question it was the rear that caused the light.

The retractable procedure does both sides, once you do the retracting procedure you can push the brake pistons back in on both sides. For the 2010 E350 you don't have to do this, but I'm not 100% sure, but I think on that one you can just push the piston back. An easy way to check is just to try to push the piston back (don't use a lot of force, just a bit) If the piston starts going back you are good, if it won't move then you need a retractible procedure, but I think the 2010 E350 just pushes back, its an easy one :)

@@GarageKing thank you

@@mckoylach1622 Anytime :)

Pretty much, the caliper and caliper bracket both come off, but there is a small torx bolt. It’s like a set screw on the face of the rotor. I think it’s like a T25, but don’t quote me :) once you take the caliper off, then remove the caliper bracket (2 bolts) then take out the small torx bolt on the face and you are good to go. You might need to give it a little tap with a hammer to break it free, but I don’t the MB rotors come off quite easily. Remember when you reinstall the torx bolt on the front face of the rotor does not have to be tight. It’s only a set screw. Good luck with the job :)

@@GarageKing ty GK

Hey Buddy, this is a good tool, amzn.to/3f3mueb as it presses evenly on the piston to get it back in its bore. It works great for front brakes, for the rear, sometimes its a little tight. You may have to use a big set a pliers just to move the piston a touch to get the tool in depending on how far your pads were gone. Also DON'T use the tool until you reset the rear brake or YOU WILL DAMAGE the caliper.

Hey There, that sounds like you have a short to ground somewhere in the wiring harness. The light is triggered when there is a ground to the chassis (the sensor rubs through and grounds to the brake rotor) Check the harness all the way up into the body and look for cracks in the wires insulation, if you see any damage fix it. The smallest bit of moisture that gets in can cause the wires to ground to each other and trigger the light. You have a little digging to do........

@@GarageKing Thanks. I will check that. Do you think a scan tool that can clear codes can help if the wiring is not the problem?

@@ardykharabian3453 Hey there, sorry for the late reply. I don't think a scan tool will help with that. Most scan tools check wheel speed sensors and if there is a problem with the ABS, but this is different because if the light is on the computer does not think there is any problem, it just simply thinks you have to replace your brake pads which its normal. You would need to find out where the harness terminates and measure the wire with an ohm meter to ensure its not open.

Thank you good Sir !

You only need two sensors for the entire car, One sensor goes on the front (inner pad) I forget which side, and same for the rear, one sensor on the inner pad. I think its on the passenger side, but you will know when you take them apart as you will see the wiring harness. I did think when I first did the brakes that I would need 4 sensors, one on each wheel, but nope, just two!!!

Awesome! Thanks a lot!

@@hughkim4989 Anytime!!!

Today I changed the brake pads for all four wheels. I quickly test drove after working on the front ones and had no issues. The pads had plenty of life but I replaced them anyway. Then I test drove again after working on the rear ones, and I noticed that there were scraping/grinding sounds from the rear left (not sure if the rear right one made the same sound). Did you have the same issue?

@@hughkim4989 Hey Buddy, you should not hear any scraping. When you drive it, is it always scraping on only when you apply the brakes? If it’s always I’ll bet it something simple like the backing plate rubbing on the rotor. What I would do is jack it up and spin the rear wheel with your hand and take a listen. There should be no scraping. You might hear some rubbing and that can just be the new pads. If you hear steel on steel push the backing plate back with your hand. Mine were quiet after the job. Also make sure the caliper retention spring (on the outside) is properly seated. Happy Halloween and let me know if you have any other questions. Hopefully it’s something simple.

I didn't know so thank you for sharing that. You are right who would have known that the trunk could cause that problem. Thank you

You should really replace the sensor, general rule of thumb is to replace it. I know some have gotten away with reusing the old one PROVIDING THE LIGHT IS NOT TRIGGERED. If the light is on then the plastic housing will be worn and the copper exposed so NO. If the light is not on yet, if you look at the MB C300 W205 Front brake replacement the sensor was not worn. It's at time stamp 5:25, if you pads are like that and you can get it out without breaking it then you can try to reuse it. I still replaced it anyway but for the front you can see I probably could have gotten away with not replacing it. If the sensor looks like the one on the video you watched (rear) time stamp 8:30 then you MUST replace that sensor as the plastic insulation is worn down, and if you reuse it you could get a false light. Hopefully I helped you out and if you need anything else please let me know. Thanks buddy

Hey brother thanks for the comment and question. I find that with high quality pads you can use it, but it’s not really needed. I use it on some of my brake jobs. Definitely if the pads you buy don’t have shims on the back then use it for sure and it doesn’t hurt to use it. I do use it on most of the brake jobs I do, but I find the German cars with high quality pads that come with shims don’t really make much noise. Good eye brother !!!!

@@GarageKing Sounds good. I ask because my 2016 GLC300 was known for squealing brake issue. In fact, we filed a lawsuit against Mercedes because it was so chronic and nearly everyone would get squealing brakes during reverse in cold weather. We settled out of court for an undisclosed amount. Since then, Mercedes has apparently redesigned the pads (their supplier actually) for the 3rd time. The service bulletin for those brakes recommended the dealers use a special type of anti-squeal grease.

@@Jetfuture737 Interesting information and thanks for sharing. When I worked at the dealer we did have problems with brakes sometimes (especially when first backing up in the morning) you comment got me thinking..... Many times for GM it was due to the formulation of the pads, and the pads were updated. I know for Ford they actually replaced rear drums with a different metallurgy. So yes, anti-squeal paste on the rear is usually a really good idea, and I do use it on most of my jobs. Thanks for sharing your story and sorry you had to go through that with MB!!!!

Hey There, should be the same, as its still a W205. You have to put into fitting mode before you take off the caliper, but when I took out the bolts and the pad spring I didn't put it into fitting mode as I didn't take the caliper off. Its probably smartest to put into fitting mode and then do the rear. I was just excited to do the video haha :) As long as its in fitting mode before the caliper is removed its all good :)

@@GarageKing lol, it’s always good to watch a video of an enthusiastic demonstration. I bet you’re from Canada, you got a Canadian accent.

@@arisistible1 Ha Ha !!! You know it brother, I'm in the Greater Toronto Area, so Canada, yup. Thanks for the comment :)

Good to know and thanks for the comment !!!

Hi There, I bought these pads amzn.to/3iYC79h they are very good quality, and have a good reputation with European cars. They are Hella Pagid 355021831. I can't remember where I bought the wear sensor. You only need one, and many times if you can reuse the sensor and wire as long as there if no wear on the sensor. If you light came on its tool late.

@@GarageKing Thx u very much. My best wishes and love from Ukraine

@@katyaever8700 Thank you and hope you are doing the best you can out there right now. Best wishes from Canada !!

@@GarageKing If anybody would find for new pads for replacement, see the information below which might be useful. So genuine Mercedes Brake Pad Sets for 2015 MB C300 w205 RWD have nos. as follow: FRONT: 0084203820 or 0004209803, A0084203820; REAR: 0004208200 or 0004201420, 0004208603, 0004231812, 0084201420, A0004208200. Genuine Mercedes Brake Pad Wear Sensor 2115401717 or 2205400617, 2205400717, A2115401717. Further there is a genuine Mercedes Brake Anti-Squeal Paste (.08oz Packet) 0019899451 which has other nos. too, e.g. 0019894751, 001989945109, 001989945112, A0019899451, W01331635739 W01331641991.

@@katyaever8700 Thanks for that information, you didn't have to do that, but I thank you for doing it !!

Hey brother thanks for the comment. I didn't, the fluid will go down as the pads wear, so when you push the piston back in the fluid will go back up, but it should not overflow. The only way it overflows is if someone has topped up the brake fluid. If the fluid has never been topped up then you will be ok. Keep in mind its good to bleed them every few years. On some vehicles if the fluid is dirty I open up the bleeder and push the piston back so the dirty fluid gets expelled, then fill up the master cylinder and get out any additional air bubbles by gravity bleeding once the job is done. I better stop rambling, but to answer you question, I did not open the master cylinder cap and there was no fluid overflow.

@@GarageKing thanks for your feedback, I thought not uncapping the master cylinder would ruin the brake lines and make it harder to push the caliper piston back.. I will try it this way - again thanks excellent video

@@jmgferraz Thanks so much and glad I could help !!

Good question. I'm not sure, but it does make sense that they may both have to be off the ground. If you have jack stands I would jack the rear of the car up to get both wheels off the ground. If you have a scanner you can use that to make sure. I use a Launch CRP429 scanner as you can pick them up pretty cheap and they are good for rear brake retractions on German cars. Nice W124, those are classics !!!

@@GarageKing i figured it out, did something, dont know what, but it fixed it, and brakes are fixed thanks again.

@@casic89chillin23 That is awesome, glad you got it all figured out :)

Thanks for the great comment and good eyes you have!!! The reason is I find that when I turn rotors (to deglaze them) they are thinner, and I find they warp easier. So its a toss up, the deglazing is good, and it is better to deglaze, but it puts you at risk of warping your rotors as they are thinner (like a hot pan in the oven). I find what I do is if the finish is good then I can just replace the pads, if the finish is bad then I replace the rotor. To be honest no one in the trade turns rotors often. It use to be done all the time, but not anymore. Maybe because the manufacturers make cheaper rotors?? Or make them so they are just enough. In the old days we didn't get many warping rotors, and rotors were expensive so we resurfaced them all the time. Its just not done very much anymore. Sorry to ramble..... Hope you had a great weekend and thanks for the comment :)

@@GarageKing I like our answer and agree with it. Every time I did a brakes it was cheaper to replace them instead on turning them. I guess the reason I ask is that I was look at the beginners watching our video and to add a little more information BUT I think you did a wonderful job and you did do it in great detail. Great job thanks for listening

@@benjaminzaifert7550 Thank you for the great comment, I do agree with you. I'm glad you raised the point of reglazing the rotors as that is a question I do get from time to time. Many Thanks :)

Hey brother thanks for the comment, DON'T REMOVE THAT CENTRE NUT !!!!!! That is for your wheel bearing. To get the rotor off all you have to do is take out the torx bolt in the front of the rotor (its between the wheel studs) You can see it on the vid at the 13:30min mark. I think its a t20 or T25 and its only to align the rotor. Once you take that bolt off, there are two bolts on the rear caliper bracket. You take those off and then your rotor will just come off. It usually falls off, if it doesn't give it a light tap from the rear with a hammer and it should come right off. SO there are 5 bolts total. One on the front face of the rotor (small torx) then 4 on the REAR. I took two out in the video to get the caliper off, and there are another 2 you will see once the caliper is taken off. Hope I helped you out buddy!!!

@@GarageKing thankyou for your quick response and great video. On my 2016 C300 the display on instrumental panel says "Brake Pads Low" but also the red "Brake" light is on is this corralating to the low rear brake pads or is there a seprate issue with the E-brake system? I did a brake inspection and the rear pads are low but the fronts are in great shape. Also do you think I need to re-surface the rear rotors or just do a pad slap?

@@ddemier Hey there, we must be on different time zones as I'm asleep when you send these messages :) OK, so the red light is most likely correlating to the low pads. Once you replace the pads that light should be gone. If there is no brake pedal pulsation or vibration when you brake at higher speeds, and the finish is good on the rotors I would leave then and just change the pads. I have done this a lot and never had any issues. I find the quality of steel used on the German cars is quite good and refinishing is really not necessary unless you have a run out problem (vibration)

@@GarageKing thankyou so much. Would you reccomend re-surfacing the rear rotors even if there is no vibrations?

@@ddemier If there is no vibration, and the surface looks good "still shiny" and no grooves I would leave it. I have lost count of how many brake jobs I have done and its just not necessary to resurface them unless there is a problem. Remember resurfacing them makes them thinner and they are more prone to warp afterwards. Do be sure to clean the hub surface where the wheel attaches to, you want a good mating surface between the rotor hub and wheel.

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Yup you can still stop if the light is on, but what happens is that the brake pad material gets all worn away and then you are left with a steel backing plate that rubs the rotor and will destroy it pretty quickly. Once that happens you will loose the ability to stop pretty quickly.

@@GarageKing thank you bro

I think it should. I know its really touchy. I had to do it a few times to get it right. Its in the timing.

Hey there, you have to do it pretty quick and hold for 5 seconds. Also you have to be in the right menu. You can scroll through. See the 6 min mark in the video. You can see I'm in the service menu. If you can see your odometer mileage I don't think it will work, but I'm not sure, try going through the menus and see if you can see a service menu. If you can't then you just probably have to do it quicker, like once you hit the button in the car to turn the power one its gotta be fast, then hold.

These cars are really touchy with getting it into fitting position. You have to get the timing just right or it wont work. You can do it easily with a scanner, but it does work with the buttons, its just really touchy.

there is one sensor on the rear, and one on the front, if the sensor triggers you must do both wheels. Both front or both rear.

@@GarageKing Thank you so much for the reply but just to add the warning display doesnt indicate front or rear

Is there a way for the owner to know which it is ??

@@johnmcauley5301 normally it doesn’t let you know front or rear, you have to pull the wheel to check. You have a 50/50 shot of getting it right the first time :) also if this is the first time the brakes are going to be done then most likely it’s the front.

@@johnmcauley5301 no I don’t think so, you have to pull a wheel

Which part?

The way you handle the hardware and push the piston back.

@@zarikparsanian3940 Sorry you feel that way. I used a special caliper tool to push the pison back in straight. A lot of people use C clamps which is wrong as it pushes the caliper in on an angle. Some people even use a big set of pliers. I can't see what wrong with using a proper caliper tool to push the caliper piston back in straight? As for the hardware I'm not sure what you mean by that. I don't know a better way to do it. The car was put in brake service mode, the caliper brake was electrically wound back by the cars computer, and the piston was pushed in straight using a tool designed for that job. Sorry you were not happy with it. I know a lot of techs in the industry who use a big pair of pliers. Good thing they are not on film LOL :)