Fuel and emission control systems

Fuel tank inspection

~1min read
Caution
  • Disconnecting/connecting the quick release connector without cleaning it may possibly cause damage to the fuel pipe and quick release connector. Always clean the quick release connector joint area before disconnecting/connecting using a cloth or soft brush, and make sure that it is free of foreign material.
Note
  • This inspection is for two rollover valves integrated in the fuel tank.

1. Disconnect the plastic fuel hose and the fuel pump unit connector. (See FUEL PUMP UNIT REMOVAL/INSTALLATION.)

2. Remove the fuel tank with the fuel pump unit. (See FUEL TANK REMOVAL/INSTALLATION.)

3. Plug the fuel pipe of the fuel pump unit.

4. Connect the pump to port A.


5. Level the fuel tank.

6. Apply pressure of -2.0 kpa {-34 mmHg, -1.3 inHg}

to port A.

(1) Plug port C and verify there is vacuum from port B.

  • If there is no vacuum, replace the fuel tank.
7. Apply pressure of +5.9 kPa {+44 mmHg, +1.7 inHg}

to port A.

  • If there is no airflow, replace the fuel tank.
  • If there is airflow, turn the fuel tank upside-down and proceed to next step.
8. Turn the fuel tank upside-down and apply pressure of -2.0 kPa {-15 mmHg, -0.6 inHg}

to port A.

(1) Plug port C and verify there is no vacuum from port B.

  • If there is vacuum, replace the fuel tank.

Test yourself

A quick Mazda 6 quiz: every answer comes with an explanation and a link to the manual page.