I replaced mine not too long ago and did some searches on the subject. I think I even posted a thread in the 911 section maybe.
It is common for the hoses to swell up inside and restrict the flow and fluid and this kills pumps quickly.
My pump is soso right now, but I have a fitting that won't stop leaking. I have a new pump showing up just because this leaking fitting has caused the pump to run low a few times and I don't trust it without a new one sitting in the bed box waiting to replace it.
My replacement pump on the truck right now came from a dodge dealer, all new and with a resevoir on it.
My replacement if it shows up tomorrow, they sent me a starter today, is from napa and a rebuilt.
Some people seem to have no problems with the power steering pumps and others seem to have all sorts of fun with the pumps.
Anyway, I agree with flushing the system and while I did not put a filter on mine I thought about it. But my problem was the front seal going out and just leaking fluid and not loss of power steering assist which can mean something inside got munched a bit.
Some searches will get you some interesting reading. A few of the folks I read about having problem hoses did not replace the hoses with the first pump. Once they kept having problems they pulled the hoses and checked them and they sucked even though the outside looked great.