What may be the cause of lack of tightness in the pneumatic braking system applied in buses?

Air valves are key components of the pneumatic braking system, responsible for controlling the flow and maintaining the pressure of compressed air. Mechanical damage or wear of the seals leads to a loss of airtightness and an uncontrolled loss of air from the system. This is one of the most common causes of leaks, which directly jeopardises the vehicle's braking effectiveness.