Radiator Cap Test

WARNING: This page is about a different car, the 2008 Acura TSX, 2007 Acura TSX, 2006 Acura TSX, 2005 Acura TSX, and 2004 Acura TSX. 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 the pressure tester (B) (commercially available).

Fig 1: Installing Pressure Tester To 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.