If there are water stains or foreign matter on O-ring (*1), clean it with water and scour it with fingers.

Check that O-ring (*1) is not deformed, cracked or swollen.

Apply engine coolant to O-ring (*1) and rubber packing (*2) before using a radiator cap tester.

When using the cap tester, tilt it to 30°or more above the horizontal.

Pump the cap tester several times, and check the maximum pressure*.

• Pump speed:
• 1 pump per second

*: Even if the cap cannot maintain the maximum pressure, it is not a defect.

• Judgment criterion:

• Item	Specified Condition
  Standard value (for brand-new cap)	93.3 to 122.7 kPa (0.95 to 1.25 kgf/cm2, 13.5 to 17.8 psi)
  Minimum standard value (after using cap)	78.5 kPa (0.8 kgf/cm2, 11.4 psi)

If the maximum pressure is less than the minimum standard value, replace the radiator reservoir cap sub-assembly.