Rear Brakes

I went with Akebono ceramic pads and Balo (OEM) rotors from egermanparts. I haven't used ceramic pads before so we'll see how they perform. The brake wear sensor I ordered (gray) was incorrect. The correct sensor is the one spec'd for the right front caliper right pad (black). It is not necessary to change the parking brake shoes.

It is necessary to disable the SBC (Sensotronic Brake Control) brake system to do brake work.

1. Make sure your parking brake is off (It'll be impossible to remove your rear rotors if it's on)
2. open driver's side window


3. turn headlights to 0 position


4. lock and wait 30 sec. or more


5. unlock and wait 15 sec. or more


6. lock

DO NOT UNDER ANY CIRCUMSTANCE UNLOCK THE CAR

If you do this, it will activate the electronic braking system, pressurizing the brake hydraulic lines and push the brake pistions all the way out and require a visit to the dealer- we're trying to avoid that by doing our own brakes ;)

1. Yes, you can just unplug the SBC connector in the engine compartment on the passenger side just behind the headlight (red circled item), but then the pads will not go though their automatic seating procedure. Don't be lazy. Do things right.

Remove the rear lug nuts (17mm hex). Remember to "break" them before raising the car. Next, use a Torx T40 socket to remove the stainless caliper slide pins. Push the pins back out of their rubber sleeves and pull off the caliper. Hang it with wire from the suspension to avoid stressing the rubber brake line. Remove the two 18mm hex head bolts from the caliper mount. Remove the Torx bolt that holds the rotor to the hub. Get out a LARGE hammer and whack the rotor around the bolt holes. After a bit of heavy-hitting, start whacking on the edge of the rotor. Don't worry, you can't break anything and you're replacing the rotors anyway.

Clean up everything with a stiff wire brush. Make sure to clean the slide pins with Scotchbrite. Make sure they shine. I spray the new rotors down with 409 and then rinse them. After that I give them a good dousing of brake cleaner. Adjust the parking brake shoes with the toothed wheel so that they just touch the inside of the rotors. Put on the rotors, torque the small rotor bolt to 8 Nm. Put blue (medium strength) Loctite on the threads. Mercedes specifies replacing this bolt, but I think that's unnecessary. I rub silicone gasket maker on the part of the hub that meets the inside of the brake rotor to prevent corrosion and make the rotors easier to remove next time. Reinstall the caliper hanger and torque its two 18mm hex head bolts to 115 Nm. Again, use blue Loctite on the threads. Mercedes specifies replacing these bolts, but again, I think this is unnecessary if you are following proper torquing procedures. Push the piston back with a pry bar or LARGE channel lock pliers. I crack the bleeder screw (11mm) and drain the excess fluid out to prevent any contaminants that may be present in the fluid from being pushed back up into the SBC unit. Install the pads with a bit of silicone gasket maker on the back of each pad where it contacts the caliper. This helps prevent brake squeal. Grease the slide pins with silicone grease and make sure they slide easily through their rubber sleeves. Apply blue Loctite and torque them to 27 Nm.

Refit your wheels torquing to 130 Nm. NO Loctite on these :) Follow the procedured for reactivating the SBC system and seating the pads. Note: you need to have the driver's side F and R wheels off of the ground. I just put my car up on 4 jack stands.

1. Unlock car


2. turn key to ON


3. turn key off for 1-5 sec.


4. turn key on


5. rotate LR wheel forwards for 1-2 rotations over ~3 sec.


6. rotate LF wheel forwards until it brakes itself


7. wait until the corner lights flash 3-5 times (the car will make some noise)


8. turn ignition off


9. Start the car


10. Press brake pedal 5-10 times

If you get a fault message, repeat the above routine.

This is not a hard job. Take your time and do things right. Set aside at least 4 hours to do this job. You can always celebrate if you finish early.