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: Heater core inspection
1. Remove the A/C unit. (See A/C UNIT REMOVAL/INSTALLATION.)
2. Remove the heater core from the A/C unit.
3. Inspect for cracks, damage, and coolant leakage.
If any problems are found, replace the heater core.
4. Inspect for bent fins.
If any are bent, use a flathead screwdriver to stra ...
Mazda 6 Service Manual: Winter Driving
Carry emergency gear, including tire chains, window scraper, flares, a small
shovel, jumper cables, and a small bag of sand or salt.
Ask an Authorized Mazda Dealer to check the following:
Have the proper ratio of antifreeze in the radiator.
Inspect the battery and its cables. Cold reduces b ...