After working up, "Pioneer" sailed for Australia on 30 March 1945. She arrived in Sydney on 13 May and was transferred to Manus Island, in the Admiralty Islands, on 21 June to prepare for operations off Japan. She was still there when Japan surrendered on 15 August and had repaired 24 aircraft since her arrival. "Pioneer" arrived in Hong Kong in late September to help with the rebuilding of the colony's infrastructure. Her sailors restored power, telephone service and repaired trains and buses. She made one trip back to Manus, but was back in Hong Kong in late November. The ship sailed for Sydney the following month and departed for the UK on 17 February 1946. Upon her arrival, she was placed in reserve. "Pioneer" was sold to Thos W Ward for scrap in September 1954 and broken up in Inverkeithing.