To be fitted with the engines after it was built, the ship was towed all the way from Union Iron Works in San Francisco to the Brooklyn Navy Yard.

This independence proved crucial to victory in World War II by the ships commanded by Fleet Admiral Nimitz who as Maumee's executive officer had played a key role in the refueling developments.

With the opening of hostilities in Europe, Maumee was brought out of reserve, given an extensive overhaul at Baltimore, Maryland during which she received conventional steampower propulsion, and recommissioned 2 June 1942.

At that time she commenced her first transatlantic crossing since World War I. Steaming from Norfolk via Bermuda, she arrived Casablanca 25 November and refueled small craft during the liberation of North Africa.

She sailed for home 22 December, returning to Norfolk 9 January 1943 and completing an oil run to Aruba before getting underway again for North Africa 19 March.

Sank German submarine which surfaced in the convoy with a single shot to the subs conning tower from the 5 inch gun on the Maumee.

Maumee continued to transport fuel to north Africa until 8 July, when she was ordered to carry oil from the Netherlands West Indies to east coast Navy bases.

Three days later she ascended the Huangpu River to Shanghai where she served as a station fuel ship until 16 November, when she sailed for Pearl Harbor.

Three days later, Maumee ascended the Whangpoo [Huangpu] River to Shanghai, where the oiler served as station fuel ship until she was reassigned to the Atlantic Fleet and returned to Pearl Harbor (16 November–8 December 1945).