Cooling System: Inspection

INSPECT RADIATOR CAP SUB-ASSY
NOTE:
- If the reservoir cap has contaminations, always rinse it with water.
- Before using a radiator cap tester, wet the relief valve and pressure valve with engine coolant or water.
- When performing steps ( a) and ( b), keep the tester at an angle of over 30° above the horizontal.
1. Using a radiator cap tester, slowly pump the tester once every 3 seconds or more. Check that air is released from the vacuum valve.
  NOTE: Push the pump at a constant speed.
  
  If air is not released from the vacuum valve, replace the reservoir cap.
2. Using a radiator cap tester, pump the tester once per second. Measure the relief valve opening pressure.
NOTE: The pump speed above should be followed 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 to 123 kPa (0.95 to 1.25 kgf/cm ² , 13.5 to 17.8 psi)
- Minimum opening pressure: 78 kPa (0.8 kgf/cm ² , 11.4 psi)
If the maximum value is less than the minimum opening pressure above, replace the reservoir cap.

HINT:

Pay attention to the tester's maximum opening pressure value.

Fig 1: Inspecting Radiator Cap Sub-Assy
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