Tractor Repair: IH 856 Steering, power steering pump, relief valve

Question
QUESTION: I have an issue with the steering in my IH tractor.  I am able to steer the tractor but it turns slowly and it takes quite a bit of effort.  It is hard to steer if it is moving or stopped and my TA, clutch and brakes all seem fine.  In trying to figure it out I found that if I turn the tractor off I am not able to move steer it at all with the steering wheel (hand pump).  The sterring will will spin freely for a few turns and then slowly start to build pressure, but never enough to move the wheels.  Thanks for any help.

ANSWER: did this happen all of a sudden or slowly over a bit of time
it sounds like the relief valve for the steering is blocked or else your orbital unit is worn
they can be reconditioned.if you can locate the relief valve you could remove it inspect it clean it if necisary.i would not advice dismantling the orbital valve itself as the parts inside are timed and if put back together wrong you could turn the steering wheel into a hydraulic motor which ain't good.The best thing is to remove it and get a dann foss hydraulic dealer to recondition it


---------- FOLLOW-UP ----------

QUESTION: I don't know if it happened slowly or not because the tractor is new to me.  I will check the relief valve.  Is the orbital valve the same as the steering pump?  Thanks for the information.

Answer
The orbital valve is the valve at the bottom of the steering (underneath the steering wheel) i don't know this model of tractor so my reason for thinking the problem is here is because you should not be able to turn the wheel freely with the engine off.The power steering pump is the same pump that supplies pressure to the ta and brakes so this shouldn't be your problem but there is a priority valve a relief valve and a check valve the priority valve makes sure the steering gets oil before anything else.if the steering is stiff with the engine running and free with it off i would expect the problem to be either with the relief valve or orbital unit sorry i don't know exactly where the relief valve is for the steering but i would expect it to be on the orbital valve i hope im not giving you bad info it would be worth asking arnie jossie as he knows these tractors better than i would let me know if this info was any help