IIRC, Rock auto sells inline filters for the PS system.
IDk how you want to flush it, but I hook up to the return port on the brake booster, and pump the brakes till there is noise (keep a hand on the key, so you can have it make noise for as little time as possible, as I am sure it isnt good for it) I did this once, hoping it would fix my weak brake issue, but it didnt. This method keeps from dragging tires back and forth, but you might turn lock to lock just once during the flush to get everything out of that part of the circuit, versus just the braking portion of the PS pump circuit.
I will do it again before changing it, because IMO, unless it locks up or knocks, I shouldnt be getting much for contaminants in the system, so if i flush it a few times, then change the part, the new part is entering life in a freshly flushed system, rahter than circulating some shitty fluid as you flush it at install time. so: flush it once or twice before, and once after, a little more costly, but should give longer service life IMO.
