Checking Radiator Cap

WARNING: This page is about a different car, the 2002 Nissan Sentra. However, it is still accessible from the selected car via links, so may be relevant.

Check that there is no dirt or damage on the valve seat of the radiator cap negative-pressure valve.

Fig 1: Checking Radiator Cap Negative-Pressure Valve
Courtesy of NISSAN MOTOR CO., U.S.A.
Check that there are no abnormalities in the opening and closing conditions of the negative-pressure valve.
Pull the negative pressure valve to open it.
Check that it closes completely when released.
Check radiator cap relief pressure.

Fig 2: Checking Radiator Cap Relief Pressure
Courtesy of NISSAN MOTOR CO., U.S.A.

Standard: 78 - 98 kPa (0.78 - 0.98 bar, 0.8 - 1.0 kg/cm ² , 11 - 14 psi)

Limit: 59 kPa (0.59 bar, 0.6 kg/cm ² , 9 psi)
When connecting the radiator cap to the tester, apply water 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.