At idle all i hear is engine noise. With the engine rpm @ 1500 the hydraulics are loud/whining at rest or during operation, at max rpm hydraulics quiet down significantly. Bucket controls seem to jump at any rpm while all other controls are smooth. Replaced hydraulic filter with no change, pump coupler seems good with no play. Any ideas? Backhoe was used very little for the last 20 years until I purchased it from a cemetery. Thanks for your assistance.