Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
2021 Mazda CX-3 AWDFACTORY OEM SERVICE PROCEDURE
Fuel Tank Inspection: AWD
- Level the vehicle.
- Complete the "BEFORE SERVICE PRECAUTION". (See BEFORE SERVICE PRECAUTION .)
- Drain the fuel. (See FUEL DRAINING PROCEDURE .)
- 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 fuel tank airtightness.
- Plug the fuel pump unit pipe, and ports B and C.
U.S.A. and CANADA specs .
Except U.S.A. and CANADA specs .
- Apply pressure of 5.9 kPa {44 mmHg, 1.7 inHg} to port A and wait for a while.
- Verify that there is no change in the pressure and no air leakage from the fuel tank.
- If there is air leakage, replace the fuel tank. (See FUEL TANK REMOVAL/INSTALLATION .)
- Plug the fuel pump unit pipe, and ports B and C.
- Remove the port C plug.
U.S.A. and CANADA specs .
Except U.S.A. and CANADA specs .
- Place the fuel tank in a level position.
- Close port A and apply 5.9 kPa {44 mmHg, 1.7 inHg} of pressure to port C, and leave it in this condition momentarily.
- Open port A and verify that the pressure decreases from 5.9 kPa {44 mmHg, 1.7 inHg}.
- If it cannot be verified, replace the fuel tank. (See FUEL TANK REMOVAL/INSTALLATION .)
- Close port A and apply -2.0 kPa {-15 mmHg, -0.59 inHg} vacuum to port C, and leave it in this condition momentarily.
- Open port A and verify that the -2.0 kPa {-15 mmHg, -0.59 inHg} negative pressure condition restores to near positive pressure.
- If it cannot be verified, replace the fuel tank. (See FUEL TANK REMOVAL/INSTALLATION .)
- Turn the fuel tank upside down.
- Apply pressure of 5.9 kPa {44 mmHg, 1.7 inHg} to port A and wait for a while.
U.S.A. and CANADA specs .
Except U.S.A. and CANADA specs .
- Verify that there is no change in the pressure and no air leakage from the port C.
- If there is air leakage, replace the fuel tank. (See FUEL TANK REMOVAL/INSTALLATION .)
Factory Service Tools
Use the Manual With the Right Hardware
Pair factory procedures with proven DIY tools so the instructions are easier to execute.
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.
