Noise from the power steering . How do I check and replace the fluids?

Either your power steering fluid level is low, your power steering fluid needs to be replaced, or your power steering pump is failing.

Have you checked the level of the power steering fluid if it is low it can cause a noise similar to what you described. The power steering pump could be starting to fail and making the noise. I would suggest checking the power steering fluid level and if low, they make some fluid that has power steering fluid conditioner, supposed to help extend the life of the power steering pump, if it is low you need to follow the lines from the pump and see if you can find a leak anywhere. also I would take notice of the color of the power steering fluid, if not too much trouble maybe take a picture of the fluid and upload it here, the fluid can break down and need to be replaced.

please check your ball joint ,bearing or zed link and replace the spoil t ones and then see

Check your fluid level first. If the fluid is low it will cause the power steering pump to make noise. Moore noticeable when in parking lots and driving in the city where you are making a lot of turns. Look for leaks. If you fill the power steering resivor to the proper level and the fluid leaks and you can not see the leak it may be your steering rack. The fluid leaks into the boots and sometimes goes un -detected. You can poke a small hole in the bottom of the boots and see if fluid leaks out. If so the steering rack is leaking and should be replaced

hi Eva.
As you turn your steering wheel it is this fluid pressure that aids in turning the wheels of your car. ... If the pump impeller is trying to move power steering fluid and starts catching air bubbles it can cause whining noises and vibrations to occur.
Maybe you've heard it at a stop light. Maybe you've heard it as you pass a car on the freeway. Or maybe you've heard it in the parking lot at work when someone is leaving. The unmistakable whine of a power steering pump can make even the most confident mechanic wonder when that car will breakdown.
Power steering pump noise is a unique noise that your car may make and once you've heard it you always know what it is. The noise is a mix of a whirring and a whining and will always vary with the speed of your engine whether your car is driving or in park. This whining noise can be subtle or extremely loud and may be worse in colder weather, or right when you first start your car.
Power steering pumps are most often vain style centrifugal pumps that are tasked with pressurizing the power steering fluid and pushing it down to your power steering gear or rack. As you turn your steering wheel it is this fluid pressure that aids in turning the wheels of your car.
There are a few reasons why you are hearing power steering pump noise from your car. First, it may simply be due to the design of the pump. Sometimes, noisy power steering pumps can continue to work flawlessly for years after they start making noise. This may simply be due to the manufacture's design or a tight tolerance in that particular pump. In this case, you would hear the noise but not see any other adverse effect like a loss in power steering, leaking fluid or a wobbly pulley. In this case, you may be able to help reduce your power steering pump noise by choosing a different type of power steering fluid, like a synthetic fluid.
Your power steering pump may also be making noises due to air trapped in the system. If the pump impeller is trying to move power steering fluid and starts catching air bubbles it can cause whining noises and vibrations to occur. Even tiny air bubbles you cannot see that are trapping in the power steering fluid may be causing the whining you are hearing. In this case, the best thing to do is flush your power steering system to try and remove the air from the system. Having air trapped in your power steering system can be difficult to diagnose so you may need to simply try a power steering flush to see if it solves your problem.
Power Steering pump noise may also be due to a failing power steering pump. As the bearings on the impeller go bad it will start to make noise as the pump is turning. If you have a bad power steering pump you usually will also experience leaks from around the pulley, a wobbly pulley, or difficulty turning the steering wheel when you are stopped. If you have multiple of these symptoms together, it is probably time to replace your power steering pump.
Lastly, and most usually, a whining power steering pump is an indication of a low fluid level. Your power steering fluid is probably something you have rarely if ever checked, so it often comes as a surprise if the level is low. Your power steering fluid reservoir is also relatively small so even a slow leak will cause a low fluid level relatively quickly. To confirm this is your problem it is as simple as checking your power steering fluid level. Some power steering reservoirs are clear so you can see through them to check how full they are. You may have to wipe away some dirt and grime to find the "full" line, but it should be easy to check. If you have an opaque power steering fluid reservoir there should be a small dipstick under the cap that will help you measure the fluid level. If it is low, then you have a leak somewhere and topping off the fluid should quite down your power steering pump.
If you discover a power steering leak, rather than simply continuing to add fluid every time it gets low, you should fix the problem permanently so you don't have to continue to check your power steering fluid level. Replacing lines or seals can be a surprisingly difficult task due to the location of your power steering pump and steering gear or rack. The easiest way to seal your leak is to do it from the inside out!

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Check for leaks, probably need to replace that p/s pump.
you typically here "noise" when the fluid is low.

if gets low definitely a leak foam is pump mixing fluid with air roar is pump cavitation check lines or pump for leak keep fluid at recommended level air bound unit can cause steering difficulty and or failure if need have trained mech look into problem

Might have low fluid, check that first, next if fluid is not a problem, its prolly the unit itself that needs replacing, if you are loosing fluid, check to see if its the lines or the housing. Lines are easy to replace and cheap

Change the power steering fluid. Use the Mercon V tranny fluid (also used in the power steering system).