Combines Neighbor having trouble with l head raising

Check the belt that drives the hydraulic pump..this could be the cause.

Cheap and relatively easy insurance is to put new kit in hydraulic pump especially if never been done.Thought my F2 was doing okay till shaft seal blew in pump.New pump kit made new combine.

had same trouble with k2, belt was loose, fixed problem when tightend belt as strawwalker mentioned.

losing flow threw internal leakage in pump or relief valve assembly in port plate behind header lift valve. If power steering still works perfectly fine I would remove and rebuild relief valve first. Good luck