What must be done before coupling air hoses together?

Before coupling air hoses together, it is essential to shake debris out and blow condensation from the hoses. This step is crucial because any debris or moisture present in the air hoses can compromise the functionality of the air brake system. If debris enters the system, it can lead to blockages or damage to air control components, resulting in potential failures in braking performance. Furthermore, any condensation can lead to moisture accumulating in the system, which can cause corrosion or freezing in colder temperatures.

Proper maintenance of the hoses, including cleaning and ensuring that they are free of contaminants, ensures that the air brake system operates efficiently and safely. This preparation helps to facilitate a secure and effective connection between the hoses, crucial for the performance of the braking system.