You press the brake pedal of your motor vehicle fully down. What is the maximum safe decrease of pressure in the braking system if the air tanks are full?

In German traffic regulations for vehicles with air brake systems, such as trucks and buses, the maximum allowable pressure drop in the brake system when pressing the brake pedal fully (with full air tanks) is 0.7 bar. This is because a larger drop would indicate possible leaks or issues in the air brake system, which could lead to brake failure or reduced braking performance. Maintaining a pressure drop within this limit ensures the brakes function safely and effectively. The other values (1.2 bar or 1.5 bar) are too high and would not meet safety standards.