A hydraulic motor circuit for driving an auger is disclosed. The circuit includes a hydraulic motor that receives oil from an oil supply via a supply line and returns oil to the oil supply via a return line. The circuit further includes a main stage pressure relief valve and a first pilot stage relief valve operable if pressure in the return line exceeds a predetermined value corresponding to an allowable inertia load acting on the motor, opening of the first pilot stage relief valve causing the main stage pressure relief valve to open, allowing flow to be diverted from the return line to the supply line and back to the motor. A control valve is configured to block flow to the first pilot stage relief valve when pressure, in the supply line is greater than pressure in the return line. If pressure in the return line exceeds pressure in the supply line, the control valve shifts open and exposes the first pilot stage relief valve to pressure in the return line.