So I have an 763 Bobcat skid steer. I was using my backhoe attachment the other day and blew a hydraulic hose. Repaired and went to the garage and grabbed a half used 5 gal. can of Bobcat all season Hydraulic/Hydrostatic Fluid. This can has always been keep in the garage and capped. I use a filtered funnel and started to top off the hydraulic fluid and the screen in the funnel caught some black jelly like slime. I poured the rest into a clear plastic container and found more. Anyone know what this might be? What compatible fluid can I use? I’ll lay up some pictures for examination. Is this normal for stored Bobcat oil?