i did not use a filter wrench. i will try tommorrow though. seems strange to me, ive never had this problem before and i never use a filter wrench to put a filter on anything. usually just for taking a tough one off. i found a picture of the filter assembly and i see where the bypass spring and valve are. is it there to relieve pressure? if so what could be causing this new rise in pressure? i also noticed in the diagram that there was some kind of pressure valve on the pump itself. is it a possible cause? could these valves be stuck and causing my problem?