Checking the expansion tank cap (Chevrolet Tahoe 2)

Caution: To avoid burns, do not remove the radiator cap or expansion tank while the engine is hot.

1. Remove the radiator cap.

2. Rinse the sealing surface of the lid with clean water.

3. Install the cover on the cooling system tester.



4. Pressurize the cap and check the pressure at which the pressure starts to drop. Compare with the nominal opening pressure of the cap valve (indicated on the lid). Estimate the rate of pressure drop.

5. Replace the cover if:

• the valve opening pressure of the cover is greater than the nominal pressure.
• the lid does not hold the nominal pressure for 10 seconds.

(The article is reprinted from the website: ChevyMan)