After replacing a leaky pressure hose on power steering pump & refilling fluid pump still whines as if fluid level is low. What could the problem?

If the hose itself is leaking (not the connection/end) , replace the hose. If the hose is more than 5 years old, I'd probably just replace it. If it's the low pressure hose (return) and it's leaking at the junction, you can probably replace the clamp. If it's the high pressure hose (with the machine-formed hose ends) then replace the hose - a clamp is unlikely to withstand the pressure and you don't want to take the chance of it blowing off when you're turning.

You obviously have a leak. It should be very easy to find, first, crank engine & refill power steering reservoir to proper level. Then have someone turn the steering wheel slowly while you look around the pump, hoses & rack & pinion unit. Wherever the leak is you will see fluid leaking when the steering wheel is being turned. You can also turn the wheel all the way to either the left or right until the wheel binds up, (which puts the system to full pressure and at the same time keep pressure applied to the wheel) and you will definitely find the leak. It's probably going to be 1 of your pressure hoses. Be careful driving it until you get the leak fixed as you can burn your pump up by running it without/low on fluid. Hope this helps.

Is it full of power steering fluid ? How are the hose's high pressure and low pressure ? Did you bleed the air out after changing the pump ? There is no filter .
Verify power steering fluid level per operating specification. Refer to Checking and Adding Power Steering Fluid.
Start the engine. Rotate steering wheel from left to right. Check for sign of cavitation or fluid aeration (pump noise/whining).
Verify the fluid level. Repeat the bleed procedure, if necessary.

Whining should be low power sterring fluid.
Check the power steering dipstick and keep it in the range.
If you have no power steering fluid, automatic transmission fluid ( Dexron) works fine.
Leaks best found with a flashlight, you should not need the engine running, but you will need to get under the car, and you may need to push or bend some of the plastic sheilds out of the way to look.
Most often it is a hose, high or low pressure hose to the power steering pump that leaks.
High pressure hose has fittings, low pressure hose may have a hose clamp.

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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Power steering whining sqreeching Google Search

Add power steering fluid

You must bleed the system of air when refilled with the wheels off the ground turn the wheels from side to side but don't go all the way to the stops just a half a turn from center each way the fluid level might be low and you don't know it but if it's all the way full and still whining check for hose kinks if none the pump might be an old one and the loss of fluid may have damaged it and it needs replacement

To find out witch it is,pump or rack and pinion,break loose the presure line on the power steering pump with a wench.Start the car and turn the steering wheel back and forth,you may need to loosen the nut on the power steering hose two or three turns to get the fluid to shoot out.It should come out pretty forceful.If it doesn`t,then replace the pump.If it does come out really powerful,replace the rack and pinion.

Check your wheel bearing. Make sure all is tight and ok