There is a noisy, hissing sound in the area of the relief valve.

1. Inspect for hydraulic leaks. Refer to Power Steering Gear and Pump Leaks .
2. Inspect for air in the power steering system. Refer to Power Steering System Bleeding .

Important: Noise is evident in all power steering systems. Hissing is a common noise. The hissing noise is evident at standstill parking. A hiss is a high frequency noise.The noise is present in every valve and results from a high velocity fluid passing over the valve orifice edges. There is no relationship between the hissing noise and steering performance. A hiss may be expected when the steering wheel is at the end of travel or when it is slowly turning at a standstill. Do not replace steering gear valves unless the hiss is extremely objectionable. A replacement valve will also exhibit some slight noise and is not always a cure for the objection.