I have a 2002 Chevy Silverado with a power steering pump whining noise. I checked the fluid and it's OK. Also, at an idle when I turn the steering wheel it's like there is no power steering until I give it a little gas and bring up the rpm. Is it the power steering pump? If so, how hard is it to change?
A whining noise and a lack of power assist certainly indicate a power steering pump gone bad. But I'm gonna recommend a more accurate confirmation of the failure before investing in any parts.
As a matter of fact, in 2006 General Motors completed an analysis of power steering pumps returned under warranty repair to discover a high number of "no trouble found" results. Common causes of conditions similar to what you're experiencing include contaminated (or incorrect) power steering fluid, a malfunctioning pressure relief valve, obstructed power steering hose/line, pulley improperly installed or a defective steering gear.
Every General Motors service department should have a Power Steering System Analyzer (J 44721). This is a mandatory special tool introduced in 2001 to assist in accurately diagnosing both power steering pumps and gears.
As far as pump replacement is concerned, cash labor time comes in at about 2.0 hours. If you're mechanically capable and have the special tools to remove and install the pump pulley, it shouldn't be too big of a deal. Again, have it pressure tested first.