Jd 1530 hydraulic problem

[jrraff]

My tractor has a strange hydraulic problem at idle speed I have 2200# oil pressure. when I go to increase engine speed the pressure drops to 1600#.
the pressure control valve is activating at this point to maintain power steering.
I have checked all of the spring loaded valves, none had a broken spring. I also inspected the hyd pump, no broken spring , some wear but nothing excessive, nothing was binding and the pistons showed no signs of scoring.
Any one have a thought to my problem?

 

[J_J]

From what you said, the steering valve assembly may only require 1600 psi, and dumps the rest. Where are you reading the pressure. Is the gage just after the pump, before any valve? There are valves that can split the flow, say 70/20 % and the relief valve for the steering assembly may be set to 1600 psi. I would think that steering systems would not use real high pressure.