Troubleshooting Hydraulics on JD 955 CUT

[markhart]

I have a Deere 955 CUT that is not getting hydraulics to the steering cylinder. I have done some initial diagnostics, but am coming up short for a solution. The rockshaft (3 pt) and FEL (SCV) are responsive and working. There are no obvious leaks in the lines and fittings. I tested for pressure by adding an inline gauge at the steering cylinder. There was no pressure, so I suspected the steering valve. I tested for pressure on the lines going into the steering valve, again no pressure, and there is no pressure on the steering port coming out of the flow divider.

So, unless there is something wrong with my testing, the issue seems to be in the flow divider. I have pulled the relief valve (up to poppet) , the steering port fitting, and the proportion flow divider spool. I inspected and cleaned those and re-assembled. I did not see any issues other than the outer packing gasket on the relief valve did not seem to exist as shown in the diagram (this had never been disassembled before). It still did not send pressure to the steering port. I haven't pulled the priority valve spool yet as I could not pop it, I will.

My question is, where should I be looking to solve the problem? Has anyone done maintenance on the flow divider of the 55 CUTS?

Thanks!

Mark

 

[beenthere]

:welcome:
Do you have the tech manual (paper or CD) ?

 

[markhart]

I do have the I&T Shop Manual for the 55 series. Is there another available?

 

[beenthere]

Deere has one, and I think the 955 is on the one I have. I'll glance over it to see if anything pops up.

Is this steering valve what you are calling the flow divider spool?

Added the steering operation write-up, in case it helps. Didn't find anything called a flow divider spool.

 

[Mechanos]

Here is the hydro schematic. Maybe this will help.
View attachment Hydro schematic.pdf

 

[markhart]

Beenthere, thanks for the information from the JD manual.

Those pages both refer to the steering valve itself, the Parker unit at the bottom of the steering column, it has the steering control valve and the georotor pump. I 'think' I have ruled out that unit as the problem, because there does not appear to be hydraulic pressure on the line going TO that valve from the central hydraulics.

The flow divider, with the proportional flow divider and the priority flow divider, is part of the values that are underneath the seat on the right hand side. The flow divider is the front portion of that unit, in front of the selective control valve (SCV) that controls the front end loader.

If you look at the system schematic that Mechanos sent (thanks!!) the flow divider is #16, and consists of subelements 17, 18 & 19. Interesting that #17 the priority flow divider is only found on the 755 & 855 - I wonder if that is why I could not get the hex head on that port to turn on my 955.

If you find the relevant pages in the JD material for those parts, I would be grateful to see them. Is that available on CD? Where is it available?

Honestly, although I understand how the flow divider works conceptually, I do not understand how it works mechanically, and what I should be looking for to get it working correctly.

 

[beenthere]

yes, markhart, I see where that flow divider is thanks to the .pdf Mechanos posted. That same schematic is further down in the JD CD on the 955. (available through Deere or can find on eBay too).
I'll see if I can hit on what you need, but may toss up things that don't help you.

 

[macklong]

I have a 955 and it did not come with a front loader. I have added a new loader but it doesn't seem to have enough hydraulic pressure to operate the loader.

 

[beenthere]

Pls show the pressures that you measure at the loader connections. Pics of those fittings may also be helpful.