A squealing or whining that occurs when you turn your car's power steering while the engine is cold is an indication of air in the system. Air bubbles in the lines reduce the system's ability to create sufficient hydraulic pressure. If the noise disappears after the engine warms up, the problem is generally the result of a bad O-ring on the inlet hose joint, allowing air to be sucked into the system. Replacement of the O-ring should rectify the problem.
Place a bucket under the power steering pump.
Loosen the bolt that holds the inlet hose joint (fitting) to the power steering pump.
Remove the hose fitting from the pump and drain the fluid into the bucket.
Remove the old O-ring from the fitting. Gently lubricate the new O-ring with clean power steering fluid, and carefully install in the fitting.
Insert the fitting into the pump, and tighten with the wrench.
Start the engine and top off the power-steering pump with clean fluid.
Bleed the system to remove any trapped air.