Vickers CM11-N02R20D-21 control valve

[ETD66SS]

I bought a Pettibone 88 this past summer. It's needs some work. One of the first issues I am tackling is the control valve for the front axle leveling. It's basically just 2 HYD cylinders that pivot the front axle so when lifting a load up high, you can level the load.

The issue is when I start the machine, the leveling tips to one side and stays there, deadheading and bogging down the engine. You can still move the machine but it ofc lacks power and stalls out easily because of the deadheading.

The tilt doesn't actuate at all no matter where you move the control lever, just stays to one side.

I removed the control valve and bought a seal kit for it so I could rebuilt it this winter.

I just got it apart, and I think the spool might be too warn to rebuild.

Here are some pictures:

Imgur: The most awesome images on the Internet
Imgur: The most awesome images on the Internet
Imgur: The most awesome images on the Internet

It looks like in some spots on the spool, the chrome is warn all the way through.

First off, is the spool shot? Secondly, if it is, would this cause the deadheading issue I was experiencing?

 

[Stonehaller]

First, I do not know anything about the Pettibone. However, unless the valve scoring is causing the spool to get stuck I do not think the worn spool would be the source of your problem. The worn spool would allow leak down of the cylinder, not cause the pump to be dead headed. It is a spring centered valve so look for something that is not allowing it to return to center. Problem with the linkage or whatever actuates the valve? What is feeding pressure to this valve pair? If it comes from the power beyond of another set of valves, the dead head could be occurring in that valve bank.

 

[oldnslo]

Were the spools tight in the valve bore? From the pictures it looks like the spools are corroded Vs worn. Is there a chance this machine sat for awhile and moisture seeped into these valves? Are they mounted in manner that would allow rain or snow to collect around the end of the spools?

Agree with stonehaller that a worn spool would not cause the cylinder to shift hard one way and stay there.

 

[ETD66SS]

When I took apart the valves, there was no corrosion inside. One of the valves is not used, so it was not even supplied with a lever. That spool looks great and is not worn, however I cannot swap spools because they are match ground to each individual vale body.

The only rust I found was in the o-ring groove on the check valve plugs, I still have to clean them up fully.

You can see after pictures here:

Imgur: The most awesome images on the Internet
Imgur: The most awesome images on the Internet
Imgur: The most awesome images on the Internet
Imgur: The most awesome images on the Internet

The spool that is worn, is definitely not loose in the bore, it's still ten thousandth's of an inch clearance. However, when compared to the fit of the unused spool, it is looser. I can wiggle the worn spool in the bore ever so slightly, I imagine if I put a dial indicator on it, it move maybe .0001" at most. The other spool that didn't get any use has no play at all.

I'm all ready to finish cleaning the parts an reassemble, but I'm not confident this will fix the issue.

As far as the spools getting stuck, no, when running the machine they went back to center just fine.

As far as the way they are mounted, they are mounted horizontally, and water cannot get into the end of the spools. (see this pic for how they are mounted Imgur: The most awesome images on the Internet)

As far as what is feeding these valves, I have not really looked into that yet. I'm not sure if pressure comes from another valve bank, or tee'd off from the main pump pressure.

Here is a picture album of the machine in question: Pettibone - Album on Imgur

 

[bigdeano]

Are all the hose connections on the valve the same size? Maybe someone worked on it and hooked the hoses up wrong. It sounds like the valve port which is supposed to go to the tank is hooked to one end of the cylinder. I don't know how it could deadhead like that on its own.

 

[ETD66SS]

Are all the hose connections on the valve the same size? Maybe someone worked on it and hooked the hoses up wrong. It sounds like the valve port which is supposed to go to the tank is hooked to one end of the cylinder. I don't know how it could deadhead like that on its own.

I initially thought the same thing, but, they are all bent steel hard lines, they only go on one way, you can't mix them up really...

When I put the valves back on, I will definitely trace each line to see where it goes.

Here's a pic of the fittings: Imgur: The most awesome images on the Internet

The larger ones are for the supply/tank, and smaller ones for the cylinders.

The only other thing I can think of is the power steering is supplied by this valve bank from this top port here: Imgur: The most awesome images on the Internet

The power steering does make a **** of a lot of whining.

 

[bigdeano]

I initially thought the same thing, but, they are all bent steel hard lines, they only go on one way, you can't mix them up really...

When I put the valves back on, I will definitely trace each line to see where it goes.

Here's a pic of the fittings: Imgur: The most awesome images on the Internet

The larger ones are for the supply/tank, and smaller ones for the cylinders.

The only other thing I can think of is the power steering is supplied by this valve bank from this top port here: Imgur: The most awesome images on the Internet

The power steering does make a **** of a lot of whining.

I have the same valve on my tractor. On mine that bottom port is hooked to the tank. The power beyond port is on the other end. Yours may not have one, I've seen them without.

I think you've found the problem, the power steering is doing something to deadhead the flow and the high pressure is leaking into one end of the tilt cylinder because of the worn spool. Pics of mine are attached.

 

[ETD66SS]

Hmm, ok, so the port on yours that goes to the tank, goes to the power steering on mine. I don't have that side port like you have.

Yeah, the power steering whines constantly, but ofc gets much louder when I turn the wheels.

thx for the pics. What is all that for, wing mowers or something?

 

[bigdeano]

What is all that for, wing mowers or something?

I just have a loader, 3PH and rear remotes. Takes 4 spools.

 

[oldnslo]

Not sure if these will help but here is some information that I have on the CM11 valves. One is parts breakdown and the other is data sheet showing dimensions, model code, etc.

 

[ETD66SS]

Not sure if these will help but here is some information that I have on the CM11 valves. One is parts breakdown and the other is data sheet showing dimensions, model code, etc.

Thanks, yeah I downloaded a bunch of stuff from Eaton but I'll check those out.

I just went at removed the steering control unit:

Imgur: The most awesome images on the Internet
Imgur: The most awesome images on the Internet

I don't want to pull the steering control unit apart just yet.

I guess, what I need to know is, what happens when these things wear out? Does it put pressure back into the supply which might be causing my tilt cylinders to deadhead?

The steering control unit in the machine is a Char-Lynn RE25.291 I believe Eaton bought out Char-Lynn, and an Eaton series 10 SCU is an equivalent to this unit.

 

[oldnslo]

Yes Eaton owns Char-Lynn. Typically steering units are a real challenge to dismantle and reassemble properly. I will look later to see if I have any information on these.

For safety reasons Steering should always be the first item in your system or fed by a priority flow valve. Failing steering should not cause your machine to tilt.

 

[ETD66SS]

Yes Eaton owns Char-Lynn. Typically steering units are a real challenge to dismantle and reassemble properly. I will look later to see if I have any information on these.

For safety reasons Steering should always be the first item in your system or fed by a priority flow valve. Failing steering should not cause your machine to tilt.

Well, this machine was built in 1971, maybe they didn't have all the safety regulations they have today. The original parts manual I have for the machine has a schematic, and it shows the control valves being supplied directly by the PTO pump, and the steering control unit is after.

I rebuilt the HST unit on my Ford 1620 162-Reassembly-212 - Album on Imgur , so I am pretty sure I can handle this SCU. However, there is really nothing to rebuild, just seals. Seems to me, similarly to the spool valve, these things just wear out and you have to replace...

 

[oldnslo]

ETD,
Your CM11 is configured to provide 7 GPM bypass flow to functions down stream. On every system I have worked on the steering always was a priority so that if a function stopped flow upstream you still had steering and also brakes if hydraulic brakes. Agree didn't have the safety restrictions in the 70's they do today but still pretty sure pettibone covered there *** to make sure this machine always turned and stopped.

I looked and couldn't find any info on the steering unit based on the numbers provided. I do have info on 20 series but couldn't find a series 10. Typically Eaton Char-Lynn numbers are 3 digits a - and four digits possibly another - three more digits. Example: 261-1001-001

Can you post a picture of the schematic. It might help provide some answers or raise more questions.

 

[ETD66SS]

ETD,
Your CM11 is configured to provide 7 GPM bypass flow to functions down stream. On every system I have worked on the steering always was a priority so that if a function stopped flow upstream you still had steering and also brakes if hydraulic brakes. Agree didn't have the safety restrictions in the 70's they do today but still pretty sure pettibone covered there *** to make sure this machine always turned and stopped.

I looked and couldn't find any info on the steering unit based on the numbers provided. I do have info on 20 series but couldn't find a series 10. Typically Eaton Char-Lynn numbers are 3 digits a - and four digits possibly another - three more digits. Example: 261-1001-001

Can you post a picture of the schematic. It might help provide some answers or raise more questions.

I don't actually have a real HYD schematic, but I do have plumbing diagrams:

Imgur: The most awesome images on the Internet
Imgur: The most awesome images on the Internet
Imgur: The most awesome images on the Internet
Imgur: The most awesome images on the Internet
Imgur: The most awesome images on the Internet

In the diagram for the outrigger cylinders, I have the caps (item 7) as I don't have the outrigger option on my machine.

I threw in the parts break down for the Char-Lynn SCU. I have been googling all night, I am not able to come up with anything that old. If I take it apart and the steel parts look good, I'll just measure the O-rings and seal and build my own seal kit.

Ok, I did some more googling, and came up with an Eaton part number for my Char-Lynn SCU, supposedly it's a 211-1012-003

 

[oldnslo]

ETD,
That 211-1012 is a series 6 SCU according to my old literature. I am attaching some information that I have for it.
In looking at the plumbing diagrams there should be line from the CM11 valve that goes back to tank and a line that goes from the CM11 to the SCU pressure port. I will have to study the CM11 "R" inlet option further to see what happens if the steering circuit dead heads. I have to run out for an appointment but will try and look at this more thoroughly later this morning.

03-303 is a technical document that explains how the steering unit works.
06-316 is the parts breakdown.

 

[ETD66SS]

ETD,
That 211-1012 is a series 6 SCU according to my old literature. I am attaching some information that I have for it.
In looking at the plumbing diagrams there should be line from the CM11 valve that goes back to tank and a line that goes from the CM11 to the SCU pressure port. I will have to study the CM11 "R" inlet option further to see what happens if the steering circuit dead heads. I have to run out for an appointment but will try and look at this more thoroughly later this morning.

03-303 is a technical document that explains how the steering unit works.
06-316 is the parts breakdown.

Thanks a lot for your expertise, much appreciated. I'll look over those documents.

EDIT:

I disassembled the SCU, I see nothing wrong inside, looks brand new... Imgur: The most awesome images on the Internet

This model looks older than the Series 6 in the literature, there are no large O-rings for the case, just one o-ring for the face flange, and a lip seal.

I'm not finding the root cause of the deadheading in the controls valve or this orbital, so hmm.

 

[bigdeano]

It would be interesting to tee a pressure gauge into the line from the CM11 to the steering valve.

 

[ETD66SS]

It would be interesting to tee a pressure gauge into the line from the CM11 to the steering valve.

I could do that when I get it back together. I have a 10,000 psi gage.

Well, I found some very minor damage on the inner spool:

Imgur: The most awesome images on the Internet
Imgur: The most awesome images on the Internet
Imgur: The most awesome images on the Internet

It looks like maybe a burr was picked up on all 6 grooves in the same location when turning left. There is no significant damage on the outer spool.

I have no clue if this could cause any issues, grasping at straws. The steering worked, just very noisy, whined a lot.

Now I have to find the correct seal for this SCU before I pull that out.

 

[oldnslo]

ETD,
On the CM11 end plate section was there an internal plug under the the port that connects to the steering valve? I have studied the CM data sheet and believe you have an "E" end plate which has the option for power beyond. Unfortunately I could not find a good schematic of the "R" inlet and "E" outlet in the data sheet. I believe but can't prove, that having the steering blocked should not cause the tilt function to shift one direction and stop. Only possible answer I can arrive at is if this was plumbed in series with no line direct to tank. Then if the steering in blocked I would expect the tilt cylinder to fully extend and not retract due to the differential area and pressure being basically equal on both ends of the cylinder.

I believe you will have to trace some lines to see where they go to confirm it is plumbed according to the diagrams in your manual.

Best of luck and let us know what you find or if you have any further questions.