1. Remove the clamps and vacuum hose.
2. Apply both suction and pressure to the engine-side hose, and verify that air blows only toward that side.

Air bleeding
Brake pedal inspectionMazda 6 Service Manual: Advisory messages
You'll find several Warnings, Cautions, Notes, Specifications and Upper
and Lower Limits in this manual.
Warning
A Warning indicates a situation in which serious injury or death
could result if the warning is ignored.
Caution
A Caution indicates a situation in which damage to ...
Mazda 6 Service Manual: Service warnings
HANDLING REFRIGERANT
Avoid breathing air conditioning refrigerant or lubricant vapor.
Exposure may irritate eyes, nose and throat. Also, due to environmental
concerns, we urge use of recovery/recycling/recharging equipment when
draining R-134a from the air conditioning system. If accide ...