The power steering pumps are constant flow rate and displacement, vane type pumps. The pump shaft has a pressed-on pulley that is belt driven by the crankshaft pulley.
Trailer tow option vehicles are equipped with a power steering pump oil cooler. The oil cooler is mounted to the radiator support on 2.5L. On 3.9L and 5.9L the oil cooler is mounted to the engine block.
On the 3.9L and 4.7L the oil cooler is mounted to the power steering pump.