When I got tractor several years ago previous owner said it didn't have a hydraulic filter. It did but really gunked up so cleaned it up and got new filter and the screen that fits between filter and outer plate. It has the pressure sensor on it so oil only goes through screen when filter is plugged, I think. Since then I have changed oil 3 times and have changed filters 5 or 6 times. Usually PS quits and when I pull filter cover off screen is plugged, so I assume filter must be also.Last time I changed oil and filter, drained all 3 places on transmission, but after about 12 hours run time screen was plugged. Are there a difference in filters? I have used NAPA ones and other brands. IH deal;er 80 miles away.