Sailing between New Caledonia, the New Hebrides, the Fijis, and Pearl Harbor, she spent the next seven months refueling combat ships and convoys engaged in the struggle for the Solomon Islands.

Captain Arleigh Burke, Commander of the "Little Beavers" (DesRon 23) and later Chief of Naval Operations, commended Kankakee as the "most efficient tanker we have met."

Kankakee departed the West Coast on 24 August; she arrived at Kossol Roads, Palaus, on 10 October to serve as station tanker until 1 November when she shifted her base to Ulithi, Western Carolines.

After renewing her cargo at Ulithi, she sailed on 13 March to supply carriers, including Franklin (CV-13) and Langley (CVL-27) as they were conducting air strikes on Kyūshū, the Inland Sea, and the Ryukyus.

Completing her Ryukyus duty on 14 June, she resumed support on 3 July for the 3rd Fleet as Task Force 38 conducted devastating aerial and naval bombardments on the "home islands" from Hokkaidō to the Inland Sea.

Kankakee steamed southeast of Japan as offensive operations ceased on 15 August; but she maintained logistic support until her return to Ulithi on 5 September.

Assigned to the Naval Overseas Transportation Service (NOTS) on 28 February 1946, Kankakee departed San Pedro on 13 March to serve as station tanker in Japan and China.

Completing this important duty on 21 November, she transported aviation gasoline from St. Rose, Louisiana, to the West Coast, arriving at Wilmington on 20 December.

From her departure at Beaumont, Texas, on 12 September to her arrival at New York on 31 May 1955 she conducted two, seven-month deployments to the Mediterranean in support of 6th Fleet operations.

Reassigned to MSTS, she departed Philadelphia on 26 December for eight months of Atlantic fuel-shuttle duty that carried her from the eastern seaboard and Venezuela to Newfoundland, Labrador, and the coast of western Europe.

On 24 October, two days after President Kennedy imposed a naval quarantine against the shipment of Russian offensive missiles into Cuba, Kankakee departed Newport to furnish logistic support for the fleet swiftly assembled there.

During August she supported the Fleet's Cyprus patrol as the United States continued its role of keeping the peace in the Middle East.