is used to 'sniff' coolant for combustion byproducts. It's a liquid that starts out a transparent blue and immediately reacts by turning green when the see-thru tube with a suction bulb draws in coolant vapors immediately after a radiator cap is removed. The trick is that the engine must have just run and be overheating. My buddy tests for this by strapping the car on his dyno and performing a basic load test which is a down-the-road simulation. Doing it this way, the condition of overheating is more quickly created. This tool is like majic in the right hands! After seeing how immediately this tool works, I would NEVER have a shop that didn't have it work on my car with any kind of overheating problem! Little late with your issues but I hope other Forum members read this.
KEEP THE LEFT LANE CLEAR FOR FASTER MOVING TRAFFIC!!!