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: Rear View Monitor
The rear view monitor provides visual images of the rear of the vehicle when
reversing.
WARNING
Always drive carefully confirming the safety of the rear and the surrounding
conditions by looking directly with your eyes: Reversing the vehicle by only
looking at the screen is dangerous as it m ...
Mazda 6 Service Manual: No.1 while vehicle is in reverse, vehicle locator mark goes forward
When performing an asterisked (*) troubleshooting inspection, shake the
wiring harness and connectors while doing the inspection to discover whether
poor contact points are the cause of any intermittent malfunction. If there
is a problem, check to make sure connectors, terminals and wiri ...