I HAVE A 1986 843 BOBCAT THE HYRDAULIC MAKING A WHINING NOISE AT LOWER ENGINE SPEED AT FASTER SPEED NOT AS NOTICABLE, I HAVE CHANGE THE FILTER AND FLUIDS TWICE, THE HYRADULIC PUMP CRACKED ON ME, NEW PUMP INSTALLED STILL HAVE WHINING NOISE, USING ORIGINAL BOBCAT FLUID, MACHINE RUNS FINE, HYDRAULIC SOME TIMES OVERFLOWS OUT OF THE FILL CAP, I USE MACHINE MOSTLY IN SNOW, DOESNT MATTER IF MACHINE IS IN GARAGE OR OUTSIDE WHEN STARTED COLD, GARAGE IS 70 DEGRESS. I HAVE NO CLUE ABOUT THE HYRADULIC SYSTEM, IM A NISSAN MASTER TECH NOT AT BOCAT TECH LOL... ANY HELP???? WHAT SHOULD I LOOK FOR? TESTS? THANKS PAUL