Radiator Test

WARNING: This page is about a different car, the 2008 Honda Pilot, 2007 Honda Pilot, and 2006 Honda Pilot. However, it is still accessible from the selected car via links, so may be relevant.

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 a commercially available pressure tester (A) to the radiator, and apply a pressure of 93-123 kPa (0.95-1.25 kgf/cm² ,14-18 psi).

Fig 1: Attaching Pressure Tester To Radiator
Courtesy of AMERICAN HONDA MOTOR CO., INC.
Inspect for engine coolant leaks and a drop in pressure.
Remove the tester, then reinstall the radiator cap.