I'm getting a persistent whine from the power steering pump. I've identified a small leak but even when it's full of fluid, it still grinds pretty loudly. Does the whole pump need replaced? I know this is a basic question but I'm going at this alone and I've never worked on my own car before.

 

yes, the relief valve bottoms out on the housing and after time it wears the housing causing it to let fluid by all the time. this will cause more heat and foul the fluid. get as much of the old ps fluid out as you can. maybe see if you can drain the ps cooler, you should have one. your seal could be failing causing the leak. check over the hose. once cleaned up with new pump, if it still leaks, follow the oil trail right away if you can. if it goes to long its hard to track.