mY 4200 STANDARD has a hydraulic problem. Loader steering & 3pth does not work. Pumps squeels the return hose wants to collapse. I changed the oil, filter rinsed the system with disiel fuel Hydraulics worked fine with disiel fuel but when I put hydraulic oil in the loader started to work fine and in about five minutes it stopped responding. Can any one help with what or where is the problem. Thanks in advance rfewasko