Shurflo 255-313 1/2" twist-on pipe strainer
I found info about this in a FRForum 2009 thread. For those not familiar, and supposing you have one, it is a water "strainer", not exactly a "filter", and on my 2014 Forest River Forester it is just before the water pump. I check it every year and there is usually a small amout of sediment in it despite my use of double filters for city water.
As in that 2009 thread, mine is broken. I drain my water system for every winter and fill it with antifreeze. I must have missed this strainer, however, because as I was de-winterizing, water came streaming out of it and it is clearly broken. Not a big expense, ~$10 online. What I would like to hear from others is whether it should be replaced or if I can forget about it and move my winterizing valve to it - which would make it more convenient.