What can cause the air compressor in a braking system with a multi-circuit safety valve to deliver compressed air continuously?

The selected combination is correct because both piston wear in the air compressor and a leaking compressed air circuit can lead to continuous air delivery without reaching the cut-off pressure. Piston wear means the compressor cannot build sufficient pressure to stop, while a leak allows air to escape, prompting the compressor to work harder to maintain necessary pressure. It's important to recognize these issues as they directly relate to vehicle safety regulations in Germany, ensuring that braking systems function effectively. Understanding all possible causes helps in proper maintenance and compliance with traffic safety standards.