Ultraviolet Light Method

Courtesy of CHRYSLER GROUP, LLC

A leak detection additive is available through the parts department that can be added to the cooling system. The additive is highly visible under ultraviolet light (black light). Pour one ounce of the additive into the cooling system. Place the heater control unit in the HEAT position. Start and operate the engine until the radiator upper hose is warm to the touch. Aim the commercially available black light tool at components to be checked. If leaks are present, the black light will cause the additive to glow a bright green color.

The black light can be used in conjunction with a pressure tester to determine if any external leaks exist.