Radiator gas tightness detects automatic tight end cap that expands

The utility model discloses a radiator gas tightness detects automatic tight end cap that expands. This radiator gas tightness detects automatic tight end cap that expands include one end confined cylinder and with cylinder complex piston, the cylinder include the diapire of cylinder body and closed cylinder body, piston and cylinder sealing connection, the diapire is provided with the through-hole, the piston is provided with the boss that runs through the through-hole, boss and through-hole sealing connection cup joint flexible cover in the outside of boss, the tip of boss is provided with restriction elastic sleeve axial displacement's step, the piston be provided with the first inlet port of drive RAM and cylinder displacement, first inlet port is facing to the diapire of cylinder. The elastic sleeve shortens to length under the drive of boss, and the water inlet or the delivery port of radiator are plugged up in the external diameter chap, have realized quick shutoff water inlet or delivery port, and be easy and simple to handle, and is sealed reliable, has improved detection efficiency.