Checking Radiator Cap

Pull negative pressure valve to open it, and check that it close completely when released.

Fig 1: Checking Negative-Pressure Valve Operation
Courtesy of NISSAN MOTOR CO., U.S.A.
- Check that there is no dirt or damage on the valve seat of radiator cap negative-pressure valve.
- Check that there are no abnormalities in the opening and closing conditions of negative-pressure valve.
Check radiator cap relief pressure.

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

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

Limit : 59 kPa (0.6 kg/cm ² , 9 psi)

When connecting radiator cap to the radiator cap tester adapter (SST) and the radiator cap tester (commercial service tool), apply engine coolant to the cap seal surface.
Replace radiator cap if there is an unusualness in negative pressure valve, or if the relief pressure exceeds the limit.