Radiator Cap: Testing and Inspection
RADIATOR CAPINSPECTION
1. INSPECT RADIATOR CAP SUB-ASSY
NOTICE:
^ If the radiator cap is contaminated, 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 horizontal.
a. Using a radiator cap tester, slowly pump the tester and check that air is coming from the vacuum valve.
Pump speed: 1 push /3 seconds or more
NOTICE: Push the pump at a constant speed.
If air is not coming from the vacuum valve, replace the radiator cap.
b. Pump the tester and measure the relief valve opening pressure.
Pump speed: 1 push within 1 second
NOTICE: The above pump speed is for the first pump only (in order to close the vacuum valve). After the first pump, the pump speed can be reduced.
Standard opening pressure: 93 - 123 kPa (0.95 - 1.25 kgf/cm2, 13.5 - 17.8 psi)
Minimum opening pressure: 78 kPa (0.8 kgf/cm2, 11.3 psi)
If the opening pressure is less than minimum, replace the radiator cap.
HINT: Use the tester's maximum reading as the opening pressure.