How to Replace the Front Brakes on a Mercedes C230

1. Raise and support the car on jack stands. Remove the front wheels. Loosen the bleeder screw on the top back side of the caliper. Compress the piston back into the bore of the caliper. To do this, insert the screwdriver in the access hole on the caliper between the brake pad and the rotor, and pry the pad inward toward the caliper piston; the piston will move back into its bore.
2. Tighten the bleeder screw on the caliper. Disconnect the electrical connector for the low brake sensor, which is just a few inches up from the caliper, and then pull the sensor out of the brake pad.
3. Remove the slider bolts holding the caliper on. Remove the caliper and hang it up. Do not let the caliper hang by its hose. Remove the caliper mounting bracket.
4. Check the rotor for heavy grooving and thickness. The minimum thickness is embossed on the front of the rotor. Use a micrometer to see if it is within tolerance. If it is within 10 thousandths of the minimum required thickness and needs to be surfaced, it is too thin and needs to be replaced. Resurfacing will take off more than 10 thousandths. If the rotor is to thin it will warp very easily and cause vibration. If it is in tolerance, have it surfaced so the new pads are starting on a smooth surface.
5. Remove the rotor--just pull it off of the studs on the spindle. Install the new rotor. Install the caliper mounting bracket. Install the brake pads along with the low brake sensor. The brake pads just slide into their brackets. Slide the caliper over the pads and install the slider bolts.
6. Do the opposite side in the same fashion. Start the car when finished and pump the brakes several times to adjust them before trying to move the car.