My son has a 2002 oldsmobile alero, v6 that has 84,000 miles on it. The power steering pump was whining pretty bad and the high pressure power steering hose had a leak so both were replaced along with the serpentine belt. Fluid was added to the new pump and the car started but even the new pump is whining but worse than the old one. The car was left to sit for several hours and then tried again but it is still whining terribly. Do you know what the problem could be?
It's possible you got a faulty pump. Take it back where you got the work done. If it was done at a shop it'll be under warranty. If it still does it when the next one is replaced, then I would be looking into the rack and pinion. Sometimes, there can be a seal or o-ring that won't leak fluid but yet suck air into the system which in turn will cause the whining you're hearing. Hopefully and more than likely it's just a defective pump.