WARNING: This page is about a different car, the 2004 Nissan Quest. However, it is still accessible from the selected car via links, so may be relevant.

Pull the negative-pressure valve to open it and check that it closes completely when released.

Fig 1: Pulling Negative-Pressure Valve To Open It
Courtesy of NISSAN MOTOR CO., U.S.A.
- Check that there is no dirt or damage on the valve seat of the radiator cap negative-pressure valve.
- Check that there are no abnormalities in the opening and closing conditions of the negative-pressure valve.
Check radiator cap relief pressure using radiator cap tester (commercial service tool) and Tool.

Fig 2: Checking Radiator Cap Relief Pressure
Courtesy of NISSAN MOTOR CO., U.S.A.
1. Standard: 78 - 98 kPa (0.8 - 1.0 kg/cm ², 11 - 14 psi)
2. Limit: 59 kPa (0.6 kg/cm ², 9 psi)
- When connecting the radiator cap to the tester, apply water or coolant to the cap seal surface.
- Replace the radiator cap if there is an abnormality in the negative-pressure valve, or if the open-valve pressure is outside of the standard values.

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.

Safety Warning

Checking Radiator Cap

Use the Manual With the Right Hardware

When to See a Mechanic