Please Diagnose: Power Steering Problem

[Travis_R]

Something is going on with the steering on my 1998 Massey Ferguson 231 tractor. It has hard spots that wanna stop the wheel from turning mainly when you turn to the right. It will do it to the left also but not near as bad.
At idle it seems to steer fine but when the RPMs are up it struggles to steer.

Do you have an idea of what's going on? The tractor has 1,315 hours. I can send pics if needed.
Thank You

 

[flyerdan]

Can you get the wheels off the ground and see if it behaves the same way? It doesn't appear that you have a loader so it won't be quite as easy.
If it's still rough, I'd suspect that the steering box has some debris in the ball bearing track, probably from a bearing disintegrating. That doesn't explain the easy steering at idle though...

 

[2458n]

I have power steering issues with my Frontier truck and diesel 4x4 dually. Tractor is fine. Wish you a simple solution.

 

[boggen]

AGCO Parts Books -> guests -> massy ferguson from drop down menu -> 231 -> search = online part listings.

--gotta ask the obvious. are you actually moving? vs standing still and in neutral?
--are you low on fluid? looks like you need to check a small tank, just above "steering pump" itself. or check steering pump itself for fluid level (a tad hard to tell from diagrams)
--can you turn steering wheel and takes a little more turning for wheels to actually turn? (as in air in the hydraulics, or hydraulic oil leaking around valves or cylinders)
--is there any play in steering wheel itself? as in physically turning it back and forth then finally you hit something and tires finally begin turning.
--looks like you have 2 hydraulic cylinders (1 per front wheel) if i am looking at part diagrams correctly. are they bent?
--looks like a very generic simple "steering valve" modify "spool valve" that a FEL or rear remotes use in a sense. i see some 0-rings. that might of gotten torn up?
--looks like there is some bearings between the actual steering wheel itself, and then the steering column that goes down to the steering valve.

 

[Travis_R]

Sorry for the late response...

The tractor has difficulty steering while moving, not sitting still, but no problem at idle.

It does not have a loader on it.

Didn't think about jacking up front end to check for resistance.

There is a significant amount of play in the steering from left to right when engine is killed.

I noticed with the fill plug out, engine running, and pump filled to full mark it didn't look like much oil was circulating like it used to do.

How could I tell if fluid is bypassing internally in the pump or the right side cylinder?

Left side cylinder was rebuilt last year by a Massey Ferguson dealer. I shipped the cylinder to them. It was leaking bad externally.

What kind of fluid should go in the power steering pump?

Got a new power steering filter today, will install tomorrow.

 

[spokane 1]

I don't know furggeys but Ive seen this problem before in steering units in general there is a decider(feeler valve) that is bad. when you turn the wheel the feeler then jets hydro fluid to the right cylinder and at the same time releases fluid from the opposite cylinder. thus you can steer.
but when the valve goes bad it refuses to release fluid from the opposite cylinder from the way you want to steer. and you have dead spots or a locked steering wheel while your turning in tiny don't want to budge moments.

its either a bad valve or dirt in a valve.

 

[Travis_R]

Is this the same as a control valve or selector valve?

 

[spokane 1]

I assume not knowing your machine that this device is inside the steering box , on some tractors its all just right up by the steering wheel. Its a nice small box with one hose in 3 hoses out. 2 pressure lines to each left right wheel cylinder and one return hose to the main pump in the trans axle.

if your steering rams are tilted there could be air in one...but usually they are mounted level. the way to bleed them is jack the rig and fire up turn one complete cycle full left then right....and its all done.

 

[Travis_R]

Does the power steering pump share the same fluid as the steering gearbox?

 

[spokane 1]

Does the power steering pump share the same fluid as the steering gearbox?

all the tractors Ive worked on all came from one transaxle pump,, they usually have a constant thru shaft drive...pump drive that also runs the pto..when the tractor is stopped clutch in the pto still runs until its disengaged. the pressure is piped along the case back up to the steering box just under the plastic shields at the steering wheel.