What is the correct action if your brakes fail while driving?

When faced with brake failure while driving, the appropriate action is to pump the brake pedal, shift to a lower gear, and use the handbrake if necessary. Pumping the brake pedal can help build up brake pressure if there is any residual brake fluid available, potentially allowing for some level of braking. Shifting to a lower gear is effective because it utilizes engine braking, helping to slow the vehicle down as the engine resists the vehicle's movement. Engaging the handbrake can provide supplemental braking force, but it should be used cautiously to avoid skidding or losing control.

The other options don't provide viable solutions to manage brake failure. Waiting for help with emergency lights would not address the immediate situation and could put you in more danger. Making a hard turn to slow down is risky and could lead to loss of control or an accident. Driving onto a sidewalk is dangerous as it poses a risk to pedestrians and can result in serious accidents. Thus, the advised course of action encompasses techniques to safely reduce speed and regain control of the vehicle.