Mazda CX-9 Grand Touring 2007 Manual page 309

Courtesy of MAZDA MOTORS CORP.
NONRETURN VALVE INSPECTION [MZI-3.5]
WARNING:
1. Follow "BEFORE SERVICE PRECAUTION" before performing any work operations to prevent fuel
from spilling from the fuel system. (See BEFORE REPAIR PROCEDURE [MZI-3.5].)
2. Disconnect the negative battery cable.
3. Remove the fuel pump unit. (See FUEL PUMP UNIT REMOVAL/INSTALLATION [MZI-3.5].)
4. Siphon the fuel from the fuel tank.
NOTE:
5. Verify that the nonreturn valve is closed.
If malfunction, replace the fuel tank. (See FUEL TANK REMOVAL/INSTALLATION [MZI-
3.5].)
6. Verify that the nonreturn valve is not stuck open and does not open even when pulled up by a finger.
If malfunction, replace the fuel tank. (See FUEL TANK REMOVAL/INSTALLATION [MZI-
3.5].)
Fig. 25: Identifying Nonreturn Valve Position
Courtesy of MAZDA MOTORS CORP.
FUEL PUMP UNIT REMOVAL/INSTALLATION [MZI-3.5]
WARNING:
2007 Mazda CX-9 Grand Touring
2007 ENGINE PERFORMANCE Fuel System (MZI-3.5) - 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
facility breakage. Fuel can also irritate skin and eyes. To prevent
this, always complete the "Fuel Line Safety Procedure", while
referring to the "BEFORE SERVICE PRECAUTION".
Nonreturn valve is integrated in the fuel tank.
The nonreturn valve is normally closed by the spring force.
Verify the nonreturn valve operation using a mirror.
Fuel line spills and leakage are dangerous. Fuel can ignite and cause