Power Steering

WARNING: This page is about a different car, the 2005 Mercury Montego, 2005 Ford Freestyle, and 2005 Ford Five Hundred. However, it is still accessible from the selected car via links, so may be relevant.

The power steering system uses a CIII power steering vane-type pump to pump the fluid from the reservoir to the rack-and-pinion steering gear. The power steering pump is mounted to the engine and driven by the engine accessory drive belt. Power steering fluid is pulled into the pump from the reservoir by vacuum. The minimum vacuum required is 68--84 kPa (20--25 in/Hg). The power steering fluid is then trapped and squeezed into a smaller area inside the pump. This action pressurizes the fluid at the output, as it flows to the rest of the system. A pressure relief/flow valve is built into the pump to control the maximum pressure. The relief pressure is between 9,997--10,894 kPa (1,450--1,580 psi). This action prevents damage to the system during different engine speeds. While under pressure, the power steering fluid flows through the high pressure power steering line to the rack-and-pinion steering gear.