L5030 GST Steering Problem

BenH · Oct 5, 2013

I have a problem with the power steering on my L5030. Unless I constantly turn the steering wheel, the wheels drift back to straight ahead, or almost straight. The steering shaft does turn from the column all the way into the steering box by the front axle. Is this most likely a hydraulic problem with the steering pump, or could there be a keyway in the steering box that has failed? The lack of steering is both to the left and right. I can turn but have to keep spinning the steering wheel to do so.

David_Kb7uns · Oct 5, 2013

I would say check the center seal in the steering cylinder, can you jack tractor up and move wheels? The steering wheel controls the orbital valve and it routes fluid to either side of cylinder when pump is running and becomes a pump when engine is off. There is also a regulating valve that supplies fluid to steering circuit and GST from one of the sections of the hydraulic pump.

David Kb7uns

BenH · Oct 5, 2013

Thanks for the reply David Kb7uns,
Do you mean that I should jack the tractor up and try moving the wheels with the steering wheel with engine off, or moving the wheels themselves by pushing and pulling from side to side? Sorry, I am not familiar with how the orbital valve functions. All hydraulics function except for the steering. That is the only problem I have had with the tractor and it is one I need to correct.

Thanks,
Ben

David_Kb7uns · Oct 5, 2013

The orbital valve puts out fluid to one side of cylinder or the other as it is turned in each direction, if you say you keep turning and the steering is going back to center while moving forward then either control valve has a problem or the cylinder has an internal leak . You could lift tractor up and with engine off try to move wheels left and right and see what happens or with engine running turn each direction until you get to the stop and see how much the steering wheel turns when against the stop, a little movement is normal but if you can keep turning the wheel with a lot of movement then I would really look at the cylinder before the valve.

Hope this is not too confusing to you.

David Kb7uns

BenH · Oct 5, 2013

David, I will try lifting the front tomorrow, turn the wheels with the engine running and with it off and see what happens. When I use the tractor now, I can turn the steering wheel forever and never reach a stopping point and with almost no resistance.

Thanks again,
Ben

ibnxe · Oct 6, 2013

From the description of your symptoms, I would agree with David. Sure sounds like you have lost the center seal in the steering cylinder.

Tx Jim · Oct 6, 2013

ibnxe said:
From the description of your symptoms, I would agree with David. Sure sounds like you have lost the center seal in the steering cylinder.

I disagree with center seal on frt cylinder being the problem. If center seal was blown I would think the frt wheels would not turn either direction because the oil would bypass. I think problem will be in steering controller.

BenH · Oct 6, 2013

I much appreciate the assistance from you all. I will be trying the suggestions David made, hopefully in a little while. Is there a way to determine if the controller is the culprit?

Thanks,
Ben

BenH · Oct 6, 2013

I raised the front wheels off the ground and with the engine off I could turn the steering wheel until wheels went as far as possible left and right. There was never a positive stop. The steering wheel would turn forever without any increase in resistance. If I turned the steering wheel a little faster than normal there was some slippage or bypass evident. The steering wheel turned much faster than the wheels responded and there was a chattering sound which I could not locate. I will get someone to listen while I turn the steering wheel and try to locate where the noise is coming from.

I tried turning the wheels both with the engine running and with it stopped and both ways resulted in no stopped turning position. The steering wheel just kept turning. I could also turn the wheels left and right by pushing and pulling the tires each direction.

Do these results indicate where the problem might be located?

Thanks,
Ben

David_Kb7uns · Oct 7, 2013

Well the valve is routing the fluid to the cylinder in the proper way and with no stoppage or increased resistance makes me believe it is the internal seal on the cylinder, driving my L3130 GST tractor today I went to the stops and with normal force on the wheel it came to a stop at each lock.

David Kb7uns

BenH · Oct 7, 2013

Thanks David. I don't think I mentioned before, but when driving the tractor I have to start spinning the steering wheel and keep spinning it just to get the turn started. Turning does not begin with a normal rotation of the steering wheel.

Ben

Tx Jim · Oct 7, 2013

If seal is actually blown on steering cyl piston with wheels turned full right one should be able to remove hyd hose(LH turn hose) from steering cyl and continue turning steering wheel to right and if seal is blown oil should come out cyl fitting where hose was attached.

BenH · Oct 7, 2013

Thanks Jim. I will try this test as well. I need to pinpoint where the problem lies since much effort is involved in either pulling the steering cylinder to replace seals or the very expensive replacement of the controller. I do not want to attack the problem from the wrong direction and I don't possess knowledge enough regarding the steering system to locate the faulty part, so suggested procedures like this are a great help in pinpointing the problem.

David_Kb7uns · Oct 8, 2013

Other then pressure/flow gauge or taking cylinder to shop for testing not much else you can do.

David Kb7uns

BenH · Oct 8, 2013

David, I hope to be able to pinpoint the problem without resorting to testing with a flow gauge or pulling the cylinder and taking it in for testing. I did not have a chance today to pull a cylinder hose and test for bypass as Tx Jim suggested trying. I hope to do that tomorrow and after researching prices, I hope it is the cylinder seal that is bad. The controller is very expensive.

Ben

BenH · Oct 9, 2013

Okay, I tried turning wheels all the way to the right, disconnecting the hose from the left side of the cylinder and continued turning steering wheel to the right. Fluid came out of the left side hose, but not the cylinder fitting. What does this indicate? To be clear, there was so much fluid coming out of the hose that I could not be sure none at all was coming out of the cylinder fitting. I don't think there was, but I didn't have someone with me to observe the fitting up close. Should the fluid be coming out of the hose at all?

Thanks,
Ben

Tx Jim · Oct 9, 2013

BenH said:
Should the fluid be coming out of the hose at all?Thanks,
Ben

No fluid should be coming out of hose. I think your tractor has a faulty steering valve.

BenH · Oct 9, 2013

Jim, the faulty steering valve is the steering controller, correct? I found a diagram of the steering system online and it looks like, since fluid is getting to the hoses which connect to the cylinder from the controller, that something in the controller is failing to control direction of flow. If my understanding is correct, when the wheel is turned right then flow to the left side should be blocked and that is a function of the steering controller. Am I right in assuming that if the cylinder seal was bad, that fluid would have blown out the cylinder fitting and not the hose end?

Much appreciated,
Ben

Tx Jim · Oct 9, 2013

BenH said:
Am I right in assuming that if the cylinder seal was bad, that fluid would have blown out the cylinder fitting and not the hose end? Much appreciated,
Ben

Yes I think the steering cylinder is good and the control valve is faulty. Your Kubota dealer service manager may have a better way to diagnose the steering problem.