Radiator Cap: Testing and Inspection

1. Remove the radiator cap.
2. Inspect radiator cap.

NOTE:
^ If the radiator 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) below, keep the radiator pump tester at an angle of over 30° above the 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).

NOTE: 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 vacuum pressure.
Pump speed: 1 push within 1 second.

NOTE: This pump speed is for the first pump only (in order to close the vacuum valve). After this, the pump speed can be reduced.

Standard opening pressure: 83 - 113 kPa (12.1 - 16.4 psi)
Minimum opening pressure: 69 kPa (10.0 psi)

NOTE: Use the tester's maximum reading as the opening pressure.

If the opening pressure is less than minimum, replace the radiator cap.

3. Install the radiator cap.