Update:

Well it's been close to a year now, that I cleaned & flushed the P/S systems & added Magnefine filters to the power steering system return lines on my 99 Ranger & 94 Taurus & both are doing well.

The shudders seem to have taken a hike so far & the P/S pump on the Taurus is even quieter than it got after I flushed the system with Seafoam Trans Tune.

It's so quiet now that you have to stand right by the passenger side front fender & listen closely to hear it's slight whine.
Before cleaning & adding the filter, you could hear it 50 feet away!!!!

So it seems, at least for my P/S systems, even though they were getting regular fluid flushes every 25-30K miles when I flushed the transmissions, that maybe the "shudders" while turning, or momentary loss of P/S boost & the noisy Taurus pump, were caused by deposits & or particles circulating in the system & maybe the Seafoam Trans Tune cleaned the deposits & the Magnefine filter has/is taking any remaining sludge, or particles out of the re-circulating fluid.

Anyway, if any of you are suffering noisy P/S pumps, or intermittent acting out/shuddering/loosing boost on your P/S system, maybe consider giving the system a good internal cleaning, by running a half can dose of Seafoam Trans Tune in the fluid until things straighten up, or quiet down, then thoroughly flush the system with the remainder of your TransTune & a couple of qts of new tranny fluid, then add a Magnefine filter to the P/S return line to keep the P/S fluid clean, as I have.

It's easy to do if you'll raise the front wheels so they can be turned lock to lock, remove the P/S return line at the cooler to drain the pump reservoir, then plug the hose to the pump reservoir & add a piece of scrap hose to the P/S cooler, the other end in your catch container.

Top off the pump reservoir with the remainder of your TransTune & new fluid, then disable the fuel pump so the engine won't run, by thumping/tripping the in cabin inertia switch, or pull it's electrical connector, or pull the fuel pumps under hood power relay, or the fuse to it.

Then have an assistant crank the engine & slowly turn the steering wheel lock to lock while you keep the P/S pump reservoir topped up with new fluid, so as not to get air bubbles in the system.

After the flush, add the Magnfine filter in the disconnected P/S pump return line at the cooler & reconnect the return line to the cooler, top off the pump reservoir, replace the P/S pump fluid cap, re-enable the fuel pump & start the engine & have the helper turn the steering wheel lock to lock about 10-15 times to bleed any air out of the system.

Stop the engine & recheck the P/S fluid level & top off if necessary.

DON'T leave the P/S pump fluid cap off, during the deairing cycles, because if you did let the fluid get low during the flush cycle & have gotten air in the system, those air bubbles are under high pressure, so when it gets back to the low pressure side of the pump reservoir, it'll POP/Burp/Spit up & you'll get a facial along with P/S fluid all over the engine & the under side of the hood!!!!
Don't ask how I know this!!!! lol
BUT I had my safety glasses on, so wear yours too, Anytime your working on a pressurized system!!!!

Anyway if you have a noisy, or acting out P/S system, before throwing parts at it, maybe consider giving it a good internal cleaning & flush with new fluid & for preventative maintenance maybe consider adding a Magnefine, or a like filter to the system to keep it clean & see how it goes for you.

Kinda a long winded post, but maybe it'll prove positive & encourage someone having problems like mine, to take action!!!!

EDIT: To answer Rockledges question about the Magnefine filters, Yes the P/S & Transmission filters are the same. You can get Magnefine's with different sized molded on hose barb fittings for different sized fluid lines, so their P/N will be diferent that way.

The Magnefine filter comes with two stainless hose clamps, so all we have to do is section the low pressure fluid line by the length of the Magnefine filters ribbed body, to fit it in.