Checking Radiator Cap

WARNING: This page is about a different car, the 2005 Nissan Quest. However, it is still accessible from the selected car via links, so may be relevant.

Inspect the radiator cap.
- Replace the cap if the metal plunger cannot be seen around the edge of the black rubber gasket.
- Replace the cap if deposits of waxy residue or other foreign material are on the black rubber gasket or the metal retainer.
NOTE: Thoroughly wipe out the radiator filler neck to remove any waxy residue or foreign material.
Pull the negative-pressure valve to open it and check that it closes completely when released.
- 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.
  
  Fig 1: Pulling Negative-Pressure Valve
  Courtesy of NISSAN MOTOR CO., U.S.A.
Check radiator cap relief pressure using Tool.

Fig 2: Checking Radiator Cap Relief Pressure
Courtesy of NISSAN MOTOR CO., U.S.A.
- Tool number: EG17650301 (J-33984-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 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.