How often should air brake reservoirs be drained?

Answer: C — At least once a day

Air brake reservoirs should be drained at least once a day to ensure they function properly and safely. This practice is essential because moisture and contaminants can accumulate in the air brake system over time. If these are not removed, they can cause corrosion, freeze in cold weather, and lead to malfunctions in the braking system. Regularly draining the reservoirs helps maintain the integrity of the air system, ensuring that the brakes operate effectively and safely during vehicle operation. This preventive measure is a key aspect of routine maintenance for vehicles equipped with air brakes and promotes the longevity of the braking system components.