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: Event Data Recorder
Event Data Recorder (U.S.A. and Canada)
This vehicle is equipped with an event data recorder (EDR). The main purpose
of an EDR is to record, in certain crash or near crash-like situations, such as
an air bag deployment or hitting a road obstacle, data that will assist in understanding
how a v ...
Mazda 6 Service Manual: Fuel pump unit inspection
Caution
It is normal to hear the fuel pump operating when the ignition
switch is turned to the ON position.
Note
To improve startability, the fuel pump control operates the fuel
pump unit when the ignition switch is turned to the ON position. Due to
this, fuel pressure is rapidly ...