John Deere 2040 with Open Center valve on FEL

[Tx Jim]

IIRC 2040 < sn 350,000 with 3 cyl engine wasn't offered with option of hyd hi-lo, reverser or pto

 

[Jimmy_G]

These are the pictures. I did not have time this evening to do the test that you mentioned, but hope to do that tomorrow night. Everything appears to be hooked up properly for the front and loader as all of the functions match what they are supposed to do on the control. I am also including a picture of one of the lines pulled off so you can see the state of the fluid that is in there now, even after they supposedly drained it and filled with fresh fluid. I also have pictures of the rear remote as well as the hose that I assume was the line that went back to the transfer case from the rear remote. I do not see where it was tied in, but recall seeing a line with a tee in it on the ground near where the remote was laying when I stopped to check on it the last time.

Unfortunately, I don’t know any history on this tractor that will tell me potentially how long it has been run with the fluid in that condition.

 

[Bentrim]

Closed center systems "pump up" to and hold top pressure until a valve is opened, when pressure drops the pump starts pumping until demand is met and the system pressure is atained then the pump "shuts down".
An open center must move oil they use a positive displacement pump. When a valve is opened low pressure oil fills the circuit until resistance is met then the pump generates only the pressure to overcome the load, if the of stroke is met or the circuit is overloaded pressure will rise until the relief blows.
A closed center system must use minimum flow, or it will overheat
an open center system must use maximum flow or it will overheat
A power beyond fitting is used in an open center valve to shut off the valves main return circuit and send it to another open center valve.
I couldn't find a "plain english" description of power beyond but if you think of a tlb the pump pushes oil to the loader valve then thru the power beyond fitting to the backhoe valve.

Basic Hydraulic Open Center System Schematic

Basic Hydraulic Open Center System Schematic. In this system, a control-valve spool must be open in the center to allow pump flow to pass through the valve and return to the reservoir.

www.engineersedge.com

Basic Hydraulic Closed Center System Schematic

This document illustrates a Basic Hydraulic Closed Center System Schematic. In this system, a pump can rest when the oil is not required to operate a function.

www.engineersedge.com

Learned a lot servicing MF and White tractors

 

[Tx Jim]

A closed center system must use minimum flow, or it will overheat

It's been established when Jimmy stated his tractor serial # is 317,012L that his tractor has closed-center hyd's so please lets not muddy the waters with open center hyd info.

I disagree with your statement when speaking of JD closed center hyd systems. Most models of JD tractors with closed center hyd's have an oil cooler that cools hyd oil when used in greater amounts than ""minimum flow"". Now if you're referring to operate a hyd orbit motor on JD CC hyd systems then yes that will heat the hyd flow if flow isn't turned down from normal flow

I learned a lot about JD closed-center hyd systems by having been employed by JD dealer for 21 yrs & serving as dealer service manager for over 1/2 of those yrs

 

[Tx Jim]

Jimmy_G
You should remove hose in photo below & install a 1'' pipe plug. Sometimes a hose similar to one in your photo is utilized for a hyd oil return on an implement such as a hyd post driver. A hose attached to tractor similar was utilized on older 2040's than your tractor for control valve for OC FEL control valve.

Also I recommend changing that milky looking hyd oil ASAP. Check breather in hyd filler cap behind seat to be sure it's not clogged with dirt. Milky oil indicates presence of H20 which is ""very detrimental"" to rear axle brake pads. If you park your tractor outside not under a shed I recommend covering gearshift area

 

[Jimmy_G]

I’ll grab some oil and a pipe plug this afternoon and change both.

I’m assuming I will not be able to get all of the oil out of the lines just by draining. Is there an additive or something I can use in the new oil to help finish getting the remaining moisture out?

As best I can tell, that hose went to the rear remote, so it should be unnecessary for the moment.

After I change the oil, I’ll try the test you suggested and confirm the valv

 

[Zebrafive]

IIRC 2040 < sn 350,000 with 3 cyl engine wasn't offered with option of hyd hi-lo, reverser or pto

Thanks, TxJim, good to know. At least he does not have to worry about water and clutch packs for these items. Main worry is the brake linings.

 

[Zebrafive]

I agree, the line in your last picture was for a return. Not really related to rear SCVs, but added for use as TxJim suggested, a post pounder that needs a free return to sump.
If you drain the hydraulic fluid, pull the sump screen and check for brake lining material.

Did you agree to buy the tractor without the rear remote(s)? My guess is they took it/them off since they would not work correctly with the OC loader valve.

Your pictures do not show where the pressure and return lines from the loader valve go to. But it does show 6 lines. OC would have 7 lines. I think they plugged the seventh port.

I am not sure what if anything can be used to scavenge the water out of the hydraulic system. The loader will also contain contaminated fluid. It might take several flushes to clear all the water out.

Unless you agreed to buy the tractor minus the rear remote(s), I would want them back. I would want the OC loader valve replaced with a CC valve.

If you can find out the manufacturer of the loader valve, you might be able to find out if a CC plug is offered for that valve. If so, that would solve one problem.

 

[Jimmy_G]

I agree, the line in your last picture was for a return. Not really related to rear SCVs, but added for use as TxJim suggested, a post pounder that needs a free return to sump.
If you drain the hydraulic fluid, pull the sump screen and check for brake lining material.

Did you agree to buy the tractor without the rear remote(s)? My guess is they took it/them off since they would not work correctly with the OC loader valve.

Your pictures do not show where the pressure and return lines from the loader valve go to. But it does show 6 lines. OC would have 7 lines. I think they plugged the seventh port.

I am not sure what if anything can be used to scavenge the water out of the hydraulic system. The loader will also contain contaminated fluid. It might take several flushes to clear all the water out.

Unless you agreed to buy the tractor minus the rear remote(s), I would want them back. I would want the OC loader valve replaced with a CC valve.

If you can find out the manufacturer of the loader valve, you might be able to find out if a CC plug is offered for that valve. If so, that would solve one problem.

While I’m draining the fluid, I’ll pull the lines from the valve to try to get more info on it.

I did get the rear remotes back - for now, I’ll just clean them up and store them in the barn. This is how I got them...

 

[Tx Jim]

Unless you agreed to buy the tractor minus the rear remote(s), I would want them back. I would want the OC loader valve replaced with a CC valve.

If you can find out the manufacturer of the loader valve, you might be able to find out if a CC plug is offered for that valve. If so, that would solve one problem.

I'm not convinced FEL control valve is open-center. I'll suggest again to perform the following simple test. Disconnect FEL hyd valve return hose from tractor, cap that fitting on tractor. With FEL control lever in neutral start engine, aim open hose in open hyd filler hole behind seat & no oil should escape open FEL control valve return hose. I think CC valve in photo is what you have.

That scv in photo below was designed to fit your closed center hyd tractor. It should worth several $100. Open center control valve had different appearance.

Trans oil suction screen Zebrafive referred to is item 30