International 475 hydraulic problem

[Harvester]

I am working on a 475 the steering is fine but the hydraulics are very slow unless I work the spool valve. Tried new filter

 

[agrimax]

Probably need the seat out and the panel below it to get at the unloader valve on the hydraulic top cover..Likely to be a blocked orifice in the unloader piston or a broken spring...

 

[Harvester]

Probably need the seat out and the panel below it to get at the unloader valve on the hydraulic top cover..Likely to be a blocked orifice in the unloader piston or a broken spring...

Thank you