Power sterring fluid comes out of pump when you shut off car

What is year--make--model?
Usually with new pump, I rotate the old fluid out while putting new fluid in, that goes with the power steering pump change.
I take the return line loose from pump that should be low pressure line, usually held on with hose clamp. The high pressure line should have threaded fitting.
Aim the return line into container, turn pulley with my fingers, the old fluid should come out return line. At the same time, you have to add new fluid to the pump reservoir. When the fluid from the return line runs clear/new fluid, your done.
If no circulation, maybe a faulty or clogged power steering line?

The most common problem with noisy power steering (whining noise) is that the power steering pump is defective. If you replace the pump make sure you flush the system with clean PS fluid or it can ruin the new pump.

power assist come from power sterrig pump
brake master cylinder produces brake pressure
if no pwer assist check power sterring fluides and lines
assuming the pump is good do to steering o.k.(not mention)
if no pedal pressure check fluide level top up and depressed sevral time then check for leakage if nothing found may be flowing back to powersterring reservoir check to see if level whent up

it sounds like power sterring, check level of fluid, inspect around pulley, if it is wet or oily looking, the seal is going bad, you can put some power sterring stop leak in it, it will buy you some time until you can change the pump

Check the power steering fluid level.
If the fluid level is low, you obviously have a leak somewhere and it should be repaired. If the level is up, watch the power steering pump while the engine is running; is the pulley turning freely?
Power steering systems are hydraulic devices. The pump provides the pressure and the steering gear or rack and pinion assembly (depending on the vehicle type) applies pressure in the direction that you are turning the wheel to assist with the steering. When the hydraulics fail or when the internal components fail, your strength is the only thing turning the steering.
But start with the fluid.

THE FLUID IS PUT INSIDE THE BONUT JUST OPEN IT AND SEE TERE IS A SPACE TO PUT FLUID FOR STERRING()AND PLS VOTE ME

This can be VERY expensive I would first contact GM customer assitance the phone number should be in your owners manual.Maybe depending on your milage they will split the cost with you.I worked 20 plus years for GM and they helped alot my customers.

You need to replace the rack and pinion.

first, check steering fluid level, then check fan belts. if thats not it, your power steering pump is probably bad.

If you have checked the belt (it still has one that is) the grinding noise will be the pump but the loss of fluid could also be the steering rack at fault, try to find out where its leaking from