With the Snap-on® Coolant Exchange (EESE336A) system from Snap-on Tools Company, automotive coolant service has been automated, accelerated and simplified. The Snap-on Coolant Exchange features a vacuum and pressure hold test that checks the cooling system in service for leaks. A panel-mounted gauge shows technicians when coolant is escaping from the system. Radiator or surge cap testing is performed with the cap installed on the vehicle and shown by the actual relief pressure in pounds per square inch (PSI).