Ford 1220 hydraulic issues

[Dylanss]

Hi everyone , hope someone can help me , I have a Ford 1220 HST and over the last year the problem has got worse , the tractor won’t move forwards unless you have almost max revs on , the lift is also jumpy , I’ve replaced all hydraulic filters that I know on both screw ons underneath tractor to rear , is there any way to determine weather it needs a new hydraulic pump or any other suggestions first TIA Dylan