Work vehicle with hydraulic assist for power off steering

A work vehicle, comprising:

• a chassis;
• a plurality of ground engaging members carried by the chassis;
• a hydraulic steering system connected with at least one of the ground engaging members, the hydraulic steering system including a steering hand pump;
• a hydraulic main supply line fluidly coupled between a pressure source and the steering hand pump, the main supply line including a check valve;
• a hydraulic sub-system including a pressurized access point;
• and
• a normally open, two position valve including an inlet fluidly coupled with the pressurized access point, an outlet fluidly coupled with the main supply line on a downstream side of the check valve, and a pilot port fluidly coupled with the main supply line on an upstream side of the check valve, the valve being operable in the closed position based on pressure in the main supply line when the main supply line is pressurized from the pressure source, the valve being operable in the open position and interconnecting the pressurized access point with the main supply line through the outlet when the main supply line is not pressurized from the pressure source.