Power Steering Fluid Fill-Up

Today I noticed some serious whirring coming from the engine bay when I turned the wheel. Hoping the power steering fluid was low, I swung by Advanced Auto in Colchester and picked up some fluid, and some Bosch platinum +4 spark plugs. After filling the pump (over-filling it, actually), the noise went away immediately. I waited on the plugs, and after doing some research on the net today, I've decided on returning the plugs, and doing a little more homework before altering the ignition system.