Remove the radiator cap (A), wet its seal with engine coolant, then install it on the pressure tester (B) (commercially available). Use a small adapter H-901122-09 (C) (commercially available) to install the radiator cap. Apply a pressure of 93 - 123 kPa (0.95 - 1.25 kgf/cm2, 14 - 18 psi). Check for a drop in pressure. If the pressure drops, replace the cap.

Wait until the engine is cool, then carefully remove the radiator cap and fill the radiator with engine coolant to the top of the filler neck. Attach the pressure tester (A) (commercially available) to the radiator. Use a small adapter H-901122-09 (B) (commercially available) to attach the pressure tester. Apply a pressure of 93 - 123 kPa (0.95 - 1.25 kgf/cm2, 14 - 18 psi). Inspect for engine coolant leaks and a drop in pressure. Remove the tester and reinstall the radiator cap. Check for engine oil in the coolant and/or coolant in the engine oil. aaa