How can you detect that a disc brake system has worn brake pads?

Your selected combination of answers is correct because both options 1 and 2 are valid methods for detecting worn brake pads in a disc brake system.

Option 1, "By the wear marks on the brake pad," is crucial because many brake pads come with built-in visual indicators that alert the driver when it's time for maintenance. This ensures that the driver can be proactive about safety and braking performance.

Option 2, "By a very low fill level in the brake fluid reservoir," is also significant. When brake pads wear down significantly, more fluid is needed to engage the brakes, which can cause the fluid level in the reservoir to drop. This is an important safety feature complying with the requirements set forth in German traffic regulations, as maintaining proper brake function is vital for avoiding accidents.

However, option 3, "By an unusually large amount of looseness in the handbrake lever," does not directly indicate worn brake pads. While it may suggest trouble with the handbrake system itself, it does not directly relate to the condition of the disc brake pads.

Understanding these indicators is key for safe driving in any traffic situation and aligns with German traffic laws that emphasize maintenance of vehicle safety systems. Always check and maintain your brake system to ensure compliance and safety on the road.