IT IS THE THIRTH TIME I CHANGE OIL..FLUSH THE PIPES..THE OIL IS STILL WHITE-GREEN.....I CHECK OIL FILTER (IT IS ONLY A METAL FILTER WHITH VERY SMALLS HOLES)DURING THE WINTER IT COME ALL FREEZE AND THE HYDROLICS SYSTEM JAM ...I HAVE TO CLEEN IT....WHAT CAN I DO TO RESOLV THE PROBLEM....IS THERE...