Mazda CX-9 Grand Touring 2009 Manual page 1661

If there is airflow, place the fuel tank upside down.
14. Apply a pressure of 3 kPa {23 mmHg, 0.9 inHg} to port B and wait for a while.
2WD
Fig. 23: Identifying Fuel Pump Unit & Plug (2WD)
Courtesy of MAZDA MOTORS CORP.
AWD
15. With the pressure still applied, verify that there is no airflow from port A.
If there is airflow, replace the fuel tank.
16. Complete the "AFTER SERVICE PRECAUTION". (See AFTER SERVICE PRECAUTION [MZI-
3.7].)
Fig. 24: Identifying Fuel Pump Unit & Plug (4WD)
Courtesy of MAZDA MOTORS CORP.
NONRETURN VALVE INSPECTION [MZI-3.7]
WARNING:
2008 Mazda CX-9 Grand Touring
2008 ENGINE Fuel System (MZI-3.7) - Mazda CX-9
Fuel is very flammable liquid. If fuel spills or leaks from the
pressurized fuel system, it will cause serious injury or death and