1. What tractor do you have?
2. Can we assume you have air in the hydraulic lines, or what is it you are taling about?
3. To get air out of loader hyd system, just move them up & down fully several times.
4. I do not understand 'air in the pto'.
5. If nothing is working hydraulicly, you might have a hyd leak, or your pump lost it's prime. we could be more helpful on what to do if we know what tractor model it is. Either prime the pump, or find & fix the suction leak.
Hope we can help.
--->Paul