I have a 753G with a 1000 hrs on it. I have a squeal at high RPM that started around 950 hrs. I did a complete pm; changed the hydraulic oil, filter and case drain filters. The squeal is still there. Could it be bad pressure relief valves?
My 763 was making the same kind of noise, sounded like hydraulics bypassing. But it was just the beltsame being loose. Tightened it up little and works like a charm.
