Mercedes-Benz S420 Brake Warning Light is on Inspection at your home or office.

Common reasons for this to happen:

• Worn brake pads: When you put your foot on the brake pedal, you are causing the brake pads to press against the brake rotors or drums, which are attached to the spinning wheels. This friction forces the wheels to slow down, and makes your car slow or stop. This constant interaction slowly wears away the pads. Every time you use the brake pedal, you’re wearing another layer off of the pads. When the pads get near the end of their life, your brake light will come on to let you know that it’s time to replace them.

• Low or leaking brake fluid: Brake fluid is responsible for transferring the force of your foot on the brake pedal to the wheel and the brake pad. Without brake fluid, your car is unable to brake. If you are leaking brake fluid, your car will soon stop braking altogether. If you’re low on brake fluid, your car’s braking ability will begin to deteriorate. Often low brake fluid goes hand in hand with worn brake pads, because the more the pads are worn, the more fluid is required for the necessary force to be accomplished.

• Emergency brake is engaged: In many cars, the brake warning light is the same as the emergency brake light. If your car is on and the emergency brake is engaged, the warning system will let you know by illuminating the brake light.

• ABS problem: Most cars have a separate warning light for ABS (anti-lock braking system) problems, but not all do. There’s a chance that a brake warning light could mean trouble with the ABS.