Well I'm not sure about changing filter / or filter elements but I have heard that sometimes it takes awhile for things inside the engine to clean up. About the hoses, you are correct, there is not much pressure going to this filter. It's a press-on type fitting on the ends of the lines. I have to say that the hardward and everything involved w/ this oilguard unit is top-notch. It's all heavy-duty USA made stuff. I think at regular highway-speed engine RPMS about 1 quart per minute goes through the filter, so every 15 mins or so all your oil will get cleaned under normal circumstances. I saw no change at all in my oil pressure but did notice that my temperature was down about a half-needle width. Probably the heat getting blown off this filter while I'm driving and cooling the oil down.