150416_Training documents

ProSteering ® Relief valve Some gears are equipped with a relief valve to limit the maximum supply pressure from the power steering pump. Knowing whether or not a gear is equipped with a relief valve is useful information in the process of identifying the gear part number. For all gear types the relief valve is typically on the outboard surface of the valve housing casting. The Sheppard type relief valve is a 1 ½” hex with a raised ‘hood’ in the center of the relief valve. The TRW type relief valve is a 7/8” hex head. The TRW type relief valve does look similar to the steel plugs used in a 4 line gear without an auxiliary assist gear. These auxiliary port plugs are a 5/8” hex head.

150416_TECHNICAL GUIDE 17