If your vehicle has hydraulic brakes and the pedal goes to the floor, what can you do?

Pumping the brake pedal is the recommended action if the brake system has lost pressure, causing the pedal to go to the floor. When you pump the brakes, you may be able to build up some hydraulic pressure in the system, which can help slow the vehicle down or bring it to a stop. This technique can sometimes create enough braking force to regain control of the vehicle, allowing for a potentially safer resolution to the situation, especially in the absence of a complete brake failure.

While the other choices may seem like viable options for stopping a vehicle, they do not address the immediate need to regain braking control in the event of a hydraulic failure. For example, turning off the ignition may stop the engine but would not help in stopping the vehicle effectively, and it could lead to steering loss as well. Calling for roadside assistance is prudent but does not provide an immediate solution to the dangerous situation. Shifting into neutral may allow the vehicle to coast, but without brakes, it won't help you stop effectively. Therefore, pumping the brake is the most direct response to the loss of brake pressure in this scenario.