Abstract: A hydraulic coupling device hydraulically couples a multi-line hose to a connector having a plurality of sockets. The coupling device comprises a screw cap, a plurality of plug pins, housed within the screw cap, and an annular holding disc for holding the plug pins. The plug pins are each connectible to a respective line of the hose. Each plug pin is engageable within a respective socket of the connector. One of the plug pins is of a larger diameter than the other plug pins, and constitutes an alignment pin for accurately aligning all the plug pins with the corresponding sockets of the connector.