Checking Radiator Cap

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.