Mustang sallye

Hi, hope I do this right, I'm new & a little confused ! I have a '99 Mustang that started giving power steering trouble a few weeks ago. Being a dumb female I thought it may just be p.s. fluid. That helped a little for a few weeks, then the same thing again. Took it to a mechanic & he replaced the pump he got from O'Reill'ys. He told me it was a bad one (remanufactured) and returned it for another one, also bad. Same thing with the 3rd one ! Then went to another mechanic thinking possibly the problem was the rack & pinion but was told that was ok, the pump was not pumping fluid. I called the first mechanic who assured me it was ? I'm not sure what to believe now - I'm out close to $800+ and the steering is still really bad and this car whines like crazy. I've been told 20 times remanufactured pumps is all that's available now. Please advise.

08'MustangDude

If your brakes are unaffected, then it's not the pump, and they should know that!
Those cars use Hydro-boost, which uses the power steering circuit for power
brakes.

This is the Hydro-boost circuit.

So, if a return line collapsed, or there is a blockage at the hydro-boost, then fluid is not getting
back to the pump. Then, fluid will blow out the fill cap, and can whine because no fluid
is returning from the rack.

Mustang sallye

Dear 08' Mustang Dude, Thank you so much for your reply. I've been through three mechanics so far that can't seem to figure out the problem. The brakes are fine, only the steering and that annoying whine is driving me nuts. I'll mention this to the "next" mechanic who supposed to be the best in town Monday when I take my car to him. My car is old & but I love him ! (Yes, it's name is Justin, lol) I have never had any trouble with it until now. Again, thanks !!