Add ATF+3 (or its superceding type) automatic transmission fluid.
See Figures 1, 2, 3 and 4
Park the vehicle on a flat, level surface and leave the engine running. Turn the steering wheel several times to the left and right to raise the fluid to normal operating temperature. With the engine running, remove the cap from the power steering fluid reservoir. This unit is separate from the pump but connected to it by hoses. There are MAX and MIN marks on the dipstick connected to the cap. Add fluid if needed.
At this time, you should inspect the hoses for signs of leakage or cracking. If either condition is noted, the defective hose or hoses should be replaced.