Final answer:
In case of brake failure where pumping the pedal doesn't help, try downshifting to slow down and use the emergency brake. Remember that hydraulic brakes rely on Pascal's principle which won't be effective if the system is compromised. Seek a safe area to coast to a stop.
Step-by-step explanation:
If your brakes fail and pumping the pedal does not work, you have a serious safety issue. You should try other methods such as downshifting to a lower gear to help slow down the car. If you have power brakes or a motorized pump system, remember that these are designed to do most of the work in the braking system. However, in a brake failure situation, the standard hydraulic brakes principles would not apply since the system is compromised. A key thing to remember is that hydraulic brakes use Pascal's principle, which involves the driver exerting force on the brake pedal that is then increased by the simple lever and the hydraulic system. This system requires that there be no air in the lines as air is compressible, and its presence would make the brakes operate inefficiently. Without the proper hydraulic pressure, the brakes will not function correctly. Therefore, aside from trying to pump the brakes, look for alternative methods to bring the vehicle to a stop safely, such as using the emergency brake or seeking an area to safely coast to a stop, avoiding hazards as much as possible.