Ive been hearing this knocking sound on my 86 k5. The frequency of the tapping sound increases w/ speed. I thought it was coming from the driver front tire. I drove slow in a parking lot to see if I could hear it. The odd thing is that it seems to go away when u turn the wheel a little to the left. I jacked up that side of the truck and spun the wheel but didnt hear anything. What could this be? Edit: I did just put on a new PS pump and lines. Could this be related to it?