How To Replace Mercedes-Benz W205 Front Brake Pads & Rotors (C300)

 

Mercedes-Benz uses the same style of brake caliper as every other manufacturer on their non-performance models. The sliding caliper is cheap to produce, easy to service and performs well in everyday driving situations. You will use your front brakes more than the rears in every case; the fronts are larger and do most of the stopping, so you'll often need to replace the front brake components sooner than the rears.

The tires and brakes on your Mercedes are the two most significant factors determining how effective it stops. Checking on the condition of your brakes and tires is as easy as looking at them, but changing worn tires is not a DIY task. However, changing the brakes on your Mercedes is a DIY job and can be done with simple hand tools by those with little experience. By following the steps below, you can ensure that your brakes will back to full strength.

 

Mercedes models and years applicable:

• 2015-2018 Mercedes-Benz C300

 

Symptoms of worn Mercedes W205 front brake pads and rotors:

• A grinding coming from the front, under braking
• Juddering or a vibration coming from the front, under braking
• Deep grooves on the rotor surface
• Dark-colored deposits on the rotor surface
• The vehicle's steering pulling to one side, under braking

 All disc brake systems have a front bias, meaning that the front brakes do most of the braking. Their increased braking responsibility will lead to more frequent replacement intervals when compared to the rears. However, driving with excessively worn rear brakes still creates reduced stopping ability.

Once the brake pad material is completely worn away, the pad's metal backing plates are forced against the rotor, destroying it. You'll hear an intense grinding noise under braking when this happens. Additionally, metal shavings will come off of the rotors and cover your wheels. If these shavings get wet, they'll coat your wheel in rust. 

 

How much will it cost to replace Mercedes W205 front brake pads and rotors?

To make it easy for you, we offer a kit that includes everything you need to service the front brakes on your W205. Included are genuine Mercedes-Benz rotors and Akebono brake pads. Akebono is an OE supplier to Audi, VW, and several other Asian and American manufacturers. Also included are the new pad wear sensors. The kit will cost right around $450. 

 

How long will it take to replace Mercedes W205 front brake pads and rotors?

The service length will depend on what you choose to do. Replacing the pads and rotors is a straightforward process that doesn't require removing and reinstalling too many parts. This part of the job should take 30 minutes per corner. 

To completely service the brakes, you'll need to flush the brake fluid as well. Having a pressure bleeder simplifies this process and significantly speeds it up. If you don't have a pressure bleeder, you'll need another person to help you out. Either way, bleeding the brakes shouldn't take longer than 20 minutes. 

 

Parts required to replace Mercedes W205 front brake pads and rotors:

• Mercedes W205 Front Brake Service Kit

 

Tools required to replace Mercedes W205 front brake pads and rotors:

• 13mm Socket
• 17mm Socket
• 21mm Socket
• T30 Socket
• Ratchets
• Vice Grips
• Flathead Screwdriver
• Torque Wrench
• Caliper Carrier Hook
• Wire Brush
• Caliper Compressor

 

Steps required to replace Mercedes W205 front brake pads and rotors:

Step 1: Remove the caliper

Jack up the front of the car and place it onto jack stands. Then, use a 17mm socket to remove the lug bolts so you can remove the wheel. Next, use a T30 socket to remove the set screw from the rotor.

If the set screw is rotating the disc, place a screwdriver into the vanes of the disc and brace it against the caliper. After that, head to the back of the caliper to remove the guide pin bolts.

Loosen the guide pin bolts with a 13mm socket. The nut that the guide pin bolts threads into will spin once the bolt is loose. Use the vice grips or a pair of needle-nose pliers to hold the nut while removing the bolt the rest of the way. 

The passenger's side caliper uses the pad wear sensor to alert you when it's time to change the pads. Pull on the wires to remove the old sensor from the connector mounted to the caliper. Now, at this point, you can pull the caliper off and hang it out of the way, but the wiring for the brake pad wear-sensor connector that mounts to the caliper will restrict your movement. For more freedom to move the caliper, remove the fastener and move the bracket out of the way. 

When you remove the caliper, don't let it hang by its brake line. The caliper's weight will put a significant strain on the rubber line and can cause it to tear. You can use zip-tires, wire coat hangers, or the caliper hangers linked above, among other things, to hang the caliper out of the way.

 

Step 2: Replace the rotor

Pull the old inner and outer pad out of the bracket. Then, use a 21mm socket to remove the caliper bracket's bolts. The rotor will likely fall off of the hub after you remove the bracket. To prevent it from falling on you, thread in the set screw or a lug bolt a couple of turns.

Remove the bracket from the knuckle, then pull the rotor off of the hub. Tap the rotor's hat with a hammer if it doesn't come free from the hub. Corrosion is holding it on, and the hammer will shock it loose.

Next, turn your attention to the caliper bracket. Note the orientation of the clips mounted to the bracket, then remove them. Use a wire brush and some brake clean to scrub off as much brake dust as you can. Doing that will ensure you won't struggle to install the new pads and clips from excess buildup. You can use a wire wheel on a drill if you have access to it. Then, use the wire wheel or wire brush to remove as much corrosion as you can from the wheel hub.

You need to push the caliper's piston back into the caliper to fit it over the new pads and rotor. Place the old inner pad onto the caliper's piston and use it with the caliper compressor to push the caliper's piston back into the caliper. 

After that, fit the new rotor to the hub. Thread in the new set screw and tighten it with the T30 Torx bit socket. The torque spec for the screw is 7Nm; however, just get it snug with your ratchet. 

Then, refit the caliper bracket to the knuckle. Thread in both bolts by hand before using the 21mm socket to torque them to 120Nm. 

 

Step 3: Refit the caliper and install the new pads

Break out the new pads and examine the tops of them to determine which is the inboard pad. The inboard pad will have the necessary mounting for the pad wear sensor. Install the new pad wear sensor by pushing the sensor's tip into the top of the inner pad. Then, place both pads into the caliper bracket. 

Next, take the caliper off of the hanger and fit it over the pads. Thread in the caliper guide pin bolts by hand before tightening them with a 13mm socket. Use the vice grips or pliers to counter hold the nut as you tighten the guide pin bolts. Refit the pad wear-sensor connector bracket if you removed it and plug in the new sensor. 

Lastly, torque the guide pin bolts to 19Nm, refit the wheel, and move onto the other side if you haven't done so already. Use a 17mm socket the tighten the lug bolts once you've threaded them in. 

 

Mercedes W205 Front Brake Torque Specs:

• Mercedes-Benz Caliper Bracket Bolts = 120Nm or 88.5 ft-lbs, of torque
• Mercedes-Benz Guide Pin Bolts = 19Nm or 26 ft-lbs, of torque
• Mercedes-Benz Rotor Set Screw = 7Nm or 5 ft-lbs, of torque

Now that you've replaced the front brake pads and rotors, you can get back to safely driving your vehicle on public roads. If you're interested in more DIYs for your Mercedes, you can visit mercedes.fcpeuro.com and subscribe to our YouTube channel.

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Written by :

Christian Schaefer

Car and motorsports-obsessed writer/editor for FCP Euro's DIY Blog. Constantly dreaming of competing behind the wheel or searching for another project. Owner of a Subaru Forester XT and a Porsche 914.