Radiator Cap Test

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

Remove the radiator cap (A), wet its seal with engine coolant, then install it on a commercially available pressure tester (B).

Fig 1: Testing Radiator Cap
Courtesy of AMERICAN HONDA MOTOR CO., INC.
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.