How to Check Power Steering Fluid
When the engine compartment is cool, wipe the lid and top of the reservoir clean. Then unscrew the cap and wipe the dipstick with a clean cloth. Screw the cap back on tightly. Then remove the cap again and check the level on the dipstick.
The level should be at the FULL COLD mark. If necessary, add fluids to the correct level.
What to use
GM Part N1052884 or N1050017.