Over the years, on both my 94 3.8L Taurus & 99 4.0L Ranger, even with 25-30K P/S system fluid flushes with the specified Motorcraft fluids, I've had intermittent P/S system off center "shudder".
These shudders have always responded favorably to a dose of Seafoam Trans Tune, but I've wondered over the years, if particulate contamination of the fluid may also be part of the puzzle & not until now, have I been able to find a product that would meet all my vehicles space & system needs.
I researched, located, ordered from Advance Auto & instaled a "Magnefine" filter in each vehicles P/S return line this weekend.
This filter seems to have been well thought through & executed & it's quality seems good, but it's kinda pricey at $19 ea, although I've seen them on the net for $15.
It's small enough to fit in restricted space, has a folded 25u filter media, with a built in bypass valve, in case it cloggs, boost won't be restricted or lost, or the filter won't expode, lol
It'll just go into bypass like a normal oil filter, relieving system back pressure, so the pump doesn't get tired &
it's built in magnet, will still continue pulling out any ferrous debris, which there shouldn't be much of in a P/S system, but there is in a tranny, which this filter is also designed to fit in it's return line.
The tranny replace time is one year, but in a P/S system, that makes far less debris, I should think we could easily get WAY more service life out of it, especially if our P/S system is clean to begin with.
Anyway I'm going to try them & see if filtering the P/S fluid will have any positive affect on the "shudders" returning over time.
Check them out to see if you think they're for you.
Edit Link 10/27/17 http://www.magnefinefilters.com/main.sc
Note that Magnefine filters are now in a Metal container & now made in the USA!