How to Fix the Brakes on a 2004 Mercedes S430

The braking system on a 2004 Mercedes S430 uses a four-wheel caliper and rotor system for maximum clamping force during braking. Hydraulic fluid is forced through steel tubing and into a mechanical caliper mechanism. The caliper forced a brake lining against the rotor, which is a disc connected to the axles and wheels. This clamping force against the rotors is what slows down and stops the Mercedes S430. The brake lining is designed to convert motion into energy (heat) through this clamping force. As this happens, the lining disintegrates. When your pad lining is 1/8-inch thick, you'll need to fix the brakes in order to continue driving your Mercedes safely.

Instructions

Place the tire wrench over the end of the lug nuts and break them loose on all of the wheels. You should only need to give the wrench 1/8 to 1/4 turn to break the lug nuts free. Do not unseat the wheel from the wheel hub as this could damage the wheel studs and the wheel as well as the brake system.

Put the floor jack under the front jack point and lift up on it. The jack point is an extension of the frame. Place jack stands under the front pinch welds located underneath the driver and passenger side door. Lower the S430 onto the jack stands.

Repeat step 2 with the rear of the Mercedes. Make sure you use the rear jack point and rear pinch welds to support the vehicle.

Finish removing the lug nuts and pull the wheel off the hub.

Visually inspect the brake lining. The brake lining is the brake pad that sits inside the caliper that covers the brake rotor disc. The lining should be more than 1/8 inch thick. If it is not, then you must replace the lining. You will also want to visually inspect the brake rotor surface. If the rotor surface is scored or pitted, replace the rotor.

Remove the top and bottom caliper mounting bolts and pull the caliper off the rotor assembly.

Secure the caliper to the Mercedes' coil spring assembly directly above the brake assembly with zip-ties. Make sure that you do not tangle or damage the rubber brake hose attached to the brake caliper assembly.

Remove the old brake linings from the caliper assembly by gently tapping them from behind with a rubber mallet.

Place the face of one of the brake pads over the caliper piston. Place a c-clamp over the top of the brake lining and the caliper assembly. Force the piston back into the caliper by tightening the old brake lining against the caliper piston. Do not twist the boot in this process. The piston boot should fold back into the caliper assembly "accordion style".

Insert the new brake pads into the caliper assembly. They will only fit one way.

Slide the rotor off the hub assembly. It should slide right off, but you may have to persuade it with a rubber mallet.

Slide a new rotor onto the hub assembly, cut the zip-ties with a wire cutter, and slide the caliper assembly over the rotor.

Place a small dab of thread locker onto the threads of the caliper bolts and tighten the caliper mounting bolts down clockwise. Once you feel resistance, give the caliper bolts an additional 1/4 turn.

Re-mount the Mercedes' wheel and tighten the lug nuts down.

Repeat steps 4 to 13 for all of the S430's wheels.

Lower the Mercedes to the ground and set the torque wrench to 100 foot-lbs. Turn each lug nut until the torque wrench clicks, indicating that the proper torque value has been reached.