Caution: To avoid burns, do not remove the radiator cap or expansion tank while the engine is hot.
1. Remove the expansion tank cap.
2. Check the expansion tank cap, see above.
3. Wash the seat of the expansion tank cap.
4. Install the cooling system tester into the expansion tank neck. Create pressure in the system (close to, but not higher than, the rated opening pressure of the cover valve).
1 - Cooling system tester, 2 - Radiator cap adapter, 3 - Expansion tank hose nipple
5. The pressure in the system should remain constant for about two minutes. Estimate the rate of pressure drop.
6. Repair any leaks found if necessary.
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