if it was low you have one of two things, air in the system or the pump is making the noise. you can bleed the system by filling the fluid up then starting the car and turning the wheel to full lock and they turn the car off. then after it sits for about 3-5 min do it again in the other direction maybe 4 or 5 times. always check to see if you have any bubbles and top off the fluid as needed.