Wait until the engine is cool, then carefully remove the expansion tank cap (A). Wet the expansion tank cap seal with engine coolant, then install it on a commercially available pressure tester (B).
2.
Apply a pressure of 93?123 kPa (0.95?1.25 kgf/cm2, 13.5? 17.8 psi).
3.
Check for a drop in pressure.
4.
If the pressure drops, replace the expansion tank cap.
