Thanks for using JA.
The system has to be bled to get rid of the air.
make sure the fluid is all the way full, leave the cover off, with the engine off turn the steering wheel left to right and right to left about 20 times, check the fluid for bubbles
if bubbles remain re do the same steps till the bubbles are almost gone.
then place the cover on, start the engine and make sure there no whining sound, if it sound ok. repeat the steps with the steering wheel then check for bubbles, your goal is to get the steering to turn with ease, no noise and no bubbles. then your done.