On-Vehicle Inspection

CHECK RADIATOR CAP SUB-ASSEMBLY
NOTE:
- If the radiator cap contains foreign matter, rinse it with water.
- Before using a radiator cap tester, wet the relief valve and pressure valve with engine coolant or water.
- When performing the 2 steps below, keep the tester at an angle of 30° or more above horizontal.
1. Slowly pump the radiator cap tester, and then check that air is being released from the vacuum valve.
  Pump speed:
  
  1 push every 3 seconds or more
  
  NOTE: Push the pump at a constant speed.
  
  If air is not being released from the vacuum valve, replace the radiator cap.
  
  Fig 1: Checking Radiator Cap Sub-Assembly
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
2. Pump the tester and measure the relief valve opening pressure.
  Pump speed:
  
  1 push within 1 second
  
  NOTE: The specified pump speed is for the first pump only. It will close the vacuum valve. Once the vacuum valve is closed, the pump speed can be reduced.
  
  Standard opening pressure:
  
  93.3 to 122.7 kPa (0.95 to 1.25 kgf/cm ² , 13.5 to 17.8 psi)
  
  Minimum opening pressure:
  
  78.5 kPa (0.8 kgf/cm ² , 11.4 psi)
  
  HINT:
  
  Use the tester's maximum reading as the opening pressure.
  
  If the maximum reading is less than the minimum opening pressure, replace the radiator cap.