Fuel Tank Inspection: AWD

Level the vehicle.
Complete the "BEFORE SERVICE PRECAUTION". (See BEFORE SERVICE PRECAUTION .)
Drain the fuel. (See FUEL DRAINING PROCEDURE .)
Using the following procedure:
6:4 split type
- Remove the rear seat cushion. (See REAR SEAT CUSHION REMOVAL/INSTALLATION .)
4:2:4 split type
- Set the rear seat aside as shown in the figure. (See REAR SEAT REMOVAL/INSTALLATION .)
Main side

Fig 1: Identifying Rear Seat (Main Side)
Courtesy of MAZDA MOTORS CORP.

Sub side

Fig 2: Identifying Rear Seat (Sub Side)
Courtesy of MAZDA MOTORS CORP.
Partially peel back the floor mat as shown in the figure.
Main side

Fig 3: Identifying Floor Mat (Main Side)
Courtesy of MAZDA MOTORS CORP.

Sub side

Fig 4: Identifying Floor Mat (Sub Side)
Courtesy of MAZDA MOTORS CORP.
Remove the service hole cover.
Main side

Fig 5: Identifying Service Hole Cover And Screws (Main Side)
Courtesy of MAZDA MOTORS CORP.

Sub side

Fig 6: Identifying Service Hole Cover And Screws (Sub Side)
Courtesy of MAZDA MOTORS CORP.
Disconnect the following parts:
Main side
- Fuel pump unit connector
- Quick release connector (See QUICK RELEASE CONNECTOR REMOVAL/INSTALLATION )
Sub side
- Fuel gauge sender unit (sub) connector
Remove the floor under cover. (See FLOOR UNDER COVER REMOVAL/INSTALLATION .)
Disconnect the HO2S connector.
Remove the TWC and HO2S as a single unit. (See EXHAUST SYSTEM REMOVAL/INSTALLATION )
Remove the propeller shaft. (See PROPELLER SHAFT REMOVAL/INSTALLATION .)
Remove the fuel tank, fuel pump unit and fuel gauge sender unit (sub) as a single unit. (See FUEL TANK REMOVAL/INSTALLATION )
Perform the following procedure to verify the fuel tank airtightness.
1. Plug the fuel pump unit pipe, ports B and C.
  
  Fig 7: Identifying Fuel Pump Unit Pipe Plugs With Ports B And C
  Courtesy of MAZDA MOTORS CORP.
2. Apply a pressure of 3 kPa {23 mmHg, 0.9 inHg} to port A and wait for a while.
3. Verify that there is no air flow leakage from the fuel tank.
  - If there is air flow, replace the fuel tank. (See FUEL TANK REMOVAL/INSTALLATION .)
Plug the fuel pump unit pipe and port B.

Fig 8: Identifying Fuel Pump Unit Pipe Plugs With Ports B
Courtesy of MAZDA MOTORS CORP.
Level the fuel tank.
Apply a pressure of 3 kPa {23 mmHg, 0.9 inHg} to port A and wait for a while.
With the pressure still applied, verify that there is air flow from port C and the pressure is 0-3 kPa {0-23 mmHg, 0-0.9 inHg}.
- If there is no air flow, replace the fuel tank. (See FUEL TANK REMOVAL/INSTALLATION .)
Apply a pressure of -0.5 kPa {-3.8 mmHg, -0.1 inHg} to port A and wait for a while.
With the pressure still applied, verify that there is air flow from port C and the pressure is -0.5-0 kPa {-3.8-0 mmHg, -0.1-0 inHg}.
- If there is no air flow, replace the fuel tank. (See FUEL TANK REMOVAL/INSTALLATION .)
- If there is air flow, place the fuel tank upside down.
Apply a pressure to port A and wait for a while.

Fig 9: Identifying Fuel Pump Unit Pipe Plugs
Courtesy of MAZDA MOTORS CORP.
With the pressure still applied, verify that there is no air flow from port C.

If there is air flow, replace the fuel tank. (See FUEL TANK REMOVAL/INSTALLATION .)