1984 555 with no steering

[rdwyer]

I finally got the 555 to start and will now turn my attention to its lack of steering. Previous owner put a new pump in and a new steering motor. Yet turning the wheel does nothing. No fluid loss at the cylinders. When the engine is off, turned the wheel and I can hear fluid squishing around in the motor. Any ideas on what to look for first?

 

[Harry in Ky]

I would start by questioning said "new steering motor". Steering pumps are replaced far more frequently than the steering valves.

You might consider the possibility of a totally blown steering cylinder piston seal. Mabey remove and cap the steering lines at the cylinder and see if dead engine steering produces some resistance in the circuit.

 

[rdwyer]

Manual instructs to first bleed the system of any air. If that doesn’t fix it, then I can check the pressure coming out of the pump and the pressure at the cylinders. Both should be around 1600 + or - 50 PSI.

If I have decent pressure at the pump. I can start following it downstream to see where the issue is.

I will have a hydraulic pressure test kit by tomorrow AM.

I’ll post on how this works out.

 

[rdwyer]

Hi all. I’m at the tractor now and can use some help. I hooked up a pressure guage to the steering cylinder and I’m getting over 2000 psi. The manual calls for 1650 plus/minus 50. Is it possible the new pump that was put on is putting too much pressure and it blew the seals in the cylinders? While my guage was on it I felt resistance and fluid was squirting from the piston that had the fitting removed for my gauge. I’m guessing I need two steering cylinders and I need to figure out how to lower the pressure from the pump. Does this sound correct?

 

[Harry in Ky]

It might help if you explained just how /where the gauge is hooked in. I'm assuming from your description you removed one line from one cylinder (again assuming there are two?) put the gauge onto the hose and left the cylinder port open? When you start the engine and turn the wheel you get 2000 PSI on the gauge and oil flowing from the open port as well?

 

[rdwyer]

It might help if you explained just how /where the gauge is hooked in. I'm assuming from your description you removed one line from one cylinder (again assuming there are two?) put the gauge onto the hose and left the cylinder port open? When you start the engine and turn the wheel you get 2000 PSI on the gauge and oil flowing from the open port as well?

Yes to all you wrote. I should have been a bit more descriptive. I followed the procedure in the manual which involved removing the line running to the top of the steering cylinder and put a gauge on it. Turning the wheel generated the 2000+ PSI. I spoke to a local hydraulics place and they told me those cylinders would not have an issue with PSI that high. He said the fact that I’m feeling resistance now that I had one end plugged indicates one or both of the steering cylinders is bad. The gauge dead ending one of the lines is doing what the cylinder should be doing but is instead just remaining open, letting the fluid escape by. Instead of doing further tests I just yanked both cylinders and have two new ones on order. I’ll eventually rebuild these two. They’ll be in on Sunday so I should know then if it’s resolved.

 

[rdwyer]

I received two new steering cylinders just now. They’re the same part number. I took pics of how the two existing cylinders are configured hydraulically but those cylinders are labeled as left and right….so two different part numbers that could have different internal plumbing. Should the new cylinders have the lines connected as the old ones did? I ask because if the line that provides pressure to turn the wheel on the old cylinders was on the 12 o’clock position with what I presume is the return T’d off just below it at the 3 o’clock position, doesn’t that imply that the new cylinders, being the same part number, will need to be plumbed in reverse given I’m flipping a cylinder to use on the other side?

Or am I overthinking this?

 

[rdwyer]

Lines are hooked up but I’ve got something wrong. Can anyone share a pic of how the lines, especially the two coming down from the frame to the cylinders are routed?

 

[GrandpaSmurf825]

Is this the correct diagram? If so it looks pretty straight forward. It says 755 but I wouldn't thing the steering would be different.

https://www.jensales.com/image/cache/catalog/manual-images/Ford-755B-TractorLoaderBackhoe-Manual_88070_4-500x500.jpg

 

[rdwyer]

Is this the correct diagram? If so it looks pretty straight forward. It says 755 but I wouldn't thing the steering would be different.

https://www.jensales.com/image/cache/catalog/manual-images/Ford-755B-TractorLoaderBackhoe-Manual_88070_4-500x500.jpg

I’m not sure. The detail is a bit grainy so I can discern the details of which line from the steering motor/valve under the dash hooks to which side of the cylinder. I’m beginning to think that maybe when the prev owner put the new valve in, he crossed the lines up.

 

[sd455dan]

I received two new steering cylinders just now. They’re the same part number. I took pics of how the two existing cylinders are configured hydraulically but those cylinders are labeled as left and right….so two different part numbers that could have different internal plumbing. Should the new cylinders have the lines connected as the old ones did? I ask because if the line that provides pressure to turn the wheel on the old cylinders was on the 12 o’clock position with what I presume is the return T’d off just below it at the 3 o’clock position, doesn’t that imply that the new cylinders, being the same part number, will need to be plumbed in reverse given I’m flipping a cylinder to use on the other side?

Or am I overthinking this?

Hope the previous OP didn't hook the lines up reversed on one of the cylinders if that is even possible it would just oppose the other if so. I would not worry yet about the pressure -sounds like it is relieving a bit high but certainly id making enough pressure

here is a pic from my 550-555 manual

 

[rdwyer]

It is definitely making pressure. Thanks for the diagram. My setup looks a bit different.

I guess I need to better understand how the system works. There are two lines running from the valve under the dash to the cylinders: one for the right and one for the left. Am I correct in assuming that when you turn the wheel to the right, you should get pressurized fluid running from the valve to the port on the right cylinder that would make it retract so the wheel tucks and you turn right? If so, if that line runs to the T fitting, not only would it provide pressure to close that ram but it would also provide pressure to the other cylinder forcing it to extend assuming I have I have it plumbed to the side that makes it extend. When it extends the return fluid is forced back up the line running to the valve. Does this sound correct? If so, then I’ll troubleshoot tomorrow based on this logic. I can use my compressor to help me determine which port causes each cylinder to retract and extend.

 

[rdwyer]

Let me simplify the question, when I turn the wheel left for a left hand turn, should the valve under the dash be pressurizing the line running to the left cylinder or the line running to the right? Keep in mind a retracted piston on the left hand side will cause the wheel to turn in that direction.

 

[sd455dan]

Let me simplify the question, when I turn the wheel left for a left hand turn, should the valve under the dash be pressurizing the line running to the left cylinder or the line running to the right? Keep in mind a retracted piston on the left hand side will cause the wheel to turn in that direction.

edit
I have not dug into my early 550 although it leaks a bit at both steering valve and the cylinder connections.

After looking closer I need an explanation also...

The steering motor must work differently than I thought at first glance. Tractor tech probably knows.

 

[rdwyer]

The first diagram below shows how I'm plumbed.

The second is the install instructions for the new pump.

Note on the pump instructions it indicates that if you have two cylinders you need to reverse the Left and the Right lines. I reversed them and disconnected them from the wheels. The steering wheels was then moving the cylinders in and out accordingly free of the wheels...buy its a bit of a hard wheel. Once hooked up to the wheels, it did not want to turn the wheels....very hard steering wheel. Then I switched the pump lines so left to left, right to right...very firm wheel...won't move. Thoughts? (cross posted on FB)