Abstract: A Locomotive fuel service truck is disclosed which comprises a motor vehicle having an elongated frame, a crane arm carried on the frame, at least one fuel pump carried by the frame connectable to a fuel oil storage tank and a fuel hose having one end connected to the pump and another end adapted to fit into a railroad diesel locomotive fuel tank, and at least one removable sand hopper carried on the frame connectable to said crane arm. The crane arm is adapted to lift and position the sand hopper over a sand pot on a diesel locomotive while fuel is being dispensed from a fuel storage tank to a locomotive fuel tank. The fuel oil storage tank may be located underground or on a trailer towed by the service truck. Another embodiment of the service truck includes a fuel oil storage tank carried on the truck frame so that the service truck can completely supply all materials and fluids to replenish a diesel locomotive without having to bring additional trucks to the site of the locomotive.