Power steering cavitation until I rack the wheel
 

Power steering cavitation until I rack the wheel side to side.

It faintly whines a little after it's been sitting for a day or two. When I rack the wheel side to side just once it goes away. I have not had any change in fluid level and it's not foamy. There no leaks that I could find at a glance but air is getting in there some how. All of my Hose clamps are new and tight I replace the fluid about a year ago with G4000. I'll have to climb under it this weekend and see what I can find.

Anyone experience this?

Rack???

I have on an A6, it turned out to be the pump. However there can be a pin hole leak in the suction line from the tank to the pump which can also cause this problem. I would double and triple check for any moisture around the power steering lines, if you can't find any fluid, replace the pump.