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: Instrument cluster removal/installation
Caution
When replacing the instrument cluster, the configuration procedure must be
performed before removing the instrument cluster. If the configuration procedure
is not performed before removing the instrument cluster, it is possible that the
instrument cluster will not operate normally. ...
Mazda 6 Service Manual: Battery Recharging
NOTE
Before performing maintenance or recharging the battery, turn off all
accessories and stop the engine.
To disconnect the battery, remove the negative cable first. Install it
last when connecting the battery.
Be sure to remove the caps before recharging the battery.
I ...