I have a 2006 HD2500 Duramax with only 48,000 miles. Lately when I start out while the truck is cold, the steering wheel feels like it's locking up or without any power assist (and this can come and go several times a minute) when I have to turn the wheel to get out of my driveway parking space. When I checked the fluid and turned the knob the fluid burped out and the pump looked full and this was stone cold! I don't remember ever checking the power steering since I got it. What order of testing or checking - where can I start to find what is causing this problem? I have this problem only when the truck has been sitting and cold, sometimes the steering will get better while cold if I give it some throttle.
