Mityvac MV4525 Coolant System Test, Diagnostic and Refill Kit Patent pending coupler combines pressure, vacuum, and temperature testing capabilities in one kit Test cooling system with engine on or off to pinpoint leaks or diagnose blown head gaskets, cracked block, or damaged head(s) Refills cooling system in minutes without trapping air that can cause overheating Components connect using self-locking quick-disconnects for easy and time saving assembly and breakdown Includes four (4) adapters for connecting to the most common radiator and coolant bottle necks found on Domestic and Asian automobile's