The intention of this link was to allow direct services to operate from the south west suburbs to Parramatta and Blacktown without requiring a change of trains at Granville.

Prior to the Y-Link's opening, passengers travelling between the Western and South lines were required to change trains at Granville.

As part of a major timetable change for the Sydney Trains network on 26 November 2017, Cumberland Line services were modified to no longer travel to and from Campbelltown, instead starting and terminating at Leppington.

These changes mean the section of the network between Glenfield and Macarthur is served exclusively by services operating via the East Hills railway line.

[3] On weekends, trains operate between Schofields and Liverpool only with early morning and late night services extending to Leppington and Richmond.

The 'Y-link' was opened in 1996 as part of former Prime Minister Paul Keating's 'Building Better Cities' programme in recognition of Parramatta's place as the capital of Sydney's west.