Checking Radiator Cap

WARNING: This page is about a different car, the 2005 Infiniti FX35. However, it is still accessible from the selected car via links, so may be relevant.

Check valve seat of radiator cap.
- Check if valve seat is swollen to the extent that the edge of the plunger cannot be seen when watching it vertically from the top.
- Check if valve seat has no soil and damage.
Fig 1: Checking Radiator Cap
Courtesy of NISSAN MOTOR CO., U.S.A.
Pull negative-pressure valve to open it, and make sure that it close completely when released.
- Make sure that there is no dirt or damage on the valve seat of radiator cap negative-pressure valve.
- Make sure that there are no unusualness in the opening and closing conditions of negative-pressure valve.
Fig 2: Pulling Negative-Pressure Valve
Courtesy of NISSAN MOTOR CO., U.S.A.
Check radiator cap relief pressure.
1. Standard:
  1. 78 - 98 kPa (0.8 - 1.0 kg/cm ² , 11 - 14 psi)
2. Limit:
  1. 59 kPa (0.6 kg/cm ² , 9 psi)
- When connecting radiator cap to the radiator cap tester (commercial service tool) and the radiator cap tester adapter [SST], apply engine coolant to the cap seal surface.
Fig 3: Checking Radiator Cap Relief Pressure
Courtesy of NISSAN MOTOR CO., U.S.A.
Replace radiator cap if there is an unusualness related to the above three.

CAUTION: When installing radiator cap, thoroughly wipe out the radiator filler neck to remove any waxy residue or foreign material.