On-Vehicle Inspection

1. If there are water stains or foreign matter on rubber packings 1, 2 or 3, clean the part(s) with water and finger scouring.
2. Check that rubber packings 1, 2 and 3 are not deformed, cracked or swollen.
   Fig 1: Locating Rubber Packings

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
3. Check that 3 and 4 are not stuck together.
4. Apply engine coolant to rubber packings 2 and 3 before using the radiator cap tester.
5. When using the cap tester, tilt it to 30° or more above the horizontal.
6. 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 

Fig 2: Checking Radiator Cap Maximum Pressure

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