I have a JD 950 tractor with a after market bucket. A while back the bucket stated to move very slow. There is no paper filter for the hydraulics on this trator, only a fine screen at the sump. The screen was dirty. I changed the oil and cleaned the screen. The bucket worked fine for only a short time. Again the screen was dirty. I figured the oil change only changed a portion of the oil, so I changed the oil again and cleaned the screen. The bucket worked good for only a short time. I am sure the screen is dirty again. Where is this "fuzz" coming from that clogging the scrren?