Review on MASTERCOOL 43301 Master Radiator Pressure by Isaac Logan

First time use of a brand new product I installed a radiator cap adapter on my Honda Civic to check for a possible coolant leak. I attached the hand pump quick connector to the radiator cap and began pressurizing the system. Air began to leak immediately after the quick coupler. I was only able to pressurize 10lbs on the first try and when I wiggled the quick connect to prevent leakage the pressure had dropped to 8lbs. I didn't hear any hissing noises so I left it on for 10 minutes. When I came back the pressure dropped to 5 pounds. I checked all the connections in the cooling system for leaks and couldn't find any liquid. I was able to pressurize the system to 18lbs and stop hissing at 17lbs on the quick connect. After 20 minutes the pressure has not changed. An hour later the pressure dropped to 16 pounds. Still no antifreeze coming out. Due to conflicting results, I'm not sure if the pressure drop is due to a leak in the cooling system or an inaudible leak in the tester's quick-connect fitting. I do not recommend this test kit to anyone.