John Deere 2040 with Open Center valve on FEL

[Jimmy_G]

So, I’m kind of a newbie here. I recently purchased an older John Deere 2040 with what I’m being told is closed center hydraulics on it. The tractor has a “newer“ John Deere 521 front end loader on it that has a valve for open center hydraulics on it. According to the guy that has looked at it for me, this means that for my three point lift to work, I have to mess with the controls for the front end loader which will allow pressure to get back to the three-point lift.

my question is this, am I destined to need to grow a third arm to be able to operate my tractor or is there a better solution out there? Google tells me that there are some certain valves that can be converted from open to closed center hydraulics, but I’m not sure about the valve on this particular front and loader. I should be picking the tractor up tomorrow from having some additional servicing done and getting this much checked out on it and can post pictures then.

Last thing, they also removed the rear hydraulic remote that was mounted on the tractor, not sure that I would ever need it, but wanted to get opinions. I only have about 8 acres to keep up and really will only need to do some light grading and brush hogging once I get it where I want it to be.

 

[npalen]

2040 with open-center hyds ceased at SN 266,749
The above quote came from this thread:

2040, Closed or Open center hydraulics?

www.greentractortalk.com

So I guess you could check your serial number to verify closed or open hydraulic system. I don't understand, if your tractor is closed center, why it would have an open center valve on the loader.
Also don't understand why they would remove the rear remote.

Some open center valves can be converted to closed center with a plug. That plug would go into the port that is normally used for a power beyond plug/fitting in an open center system.

 

[CADplans]

I have the competitive twin to your tractor, in red paint, same horsepower, same weight,, etc,,

I have had the tractor 30 years, and have never plugged anything in the rear remotes.

Using an open center valve on a closed center hydraulic system wastes fuel,
and puts excess wear on a VERY expensive hydraulic pump.

Even if you have to buy a valve, get a closed center valve,,,
or,,
grow a third arm, and prepare the checkbook for a couple thousand dollar hit for that pump.

 

[Tx Jim]

I agree with npalen in that knowing serial of JD 2040 with 3 cylinder engine is very important when it comes to hyd system. 3 cyl 2040's up to serial # 266,749 had OPEN-CENTER hyd's & after 266,750 had CLOSED-CENTER hyd's. Only reason I can think of for dealer to remove SCV is to sell the scv kit for more $$$$$. Post your tractors serial # & I'll help you diagnose/repair your tractors hyd problem. I would tell dealership to reinstall SCV or give it to you so you could sell the $750-$1000 kit if you don't want kit on tractor.

 

[Zebrafive]

I would tell the seller to put the correct loader valve on the tractor before I would buy. I would also want the rear SCV. Many uses for 1, 2, 3, even 4 rear SCVs.

 

[npalen]

So I'm trying to visualize what the "third arm" is doing with the loader valve in order to send pressure to let the 3PH operate. Seems that, for example, completely retracting the bucket cylinders and holding the valve in that position would do the trick? Also seems that bandaid would work with a closed center system with a misapplied open center valve or an open center system with and open center valve with no power beyond to the 3PH?

 

[LD1]

Get ahold of your deere dealer. First find out if your tractor IS indeed closed center. If it is see if the valve you have on that loader can simply be converted with a CC plug. If it cant (sometimes they use a different valve all together), then you need to look for a CC valve.

 

[Tx Jim]

Also seems that bandaid would work with a closed center system with a misapplied open center valve or an open center system with and open center valve with no power beyond to the 3PH?

Open center valve utilized on a closed-center hyd system is a big no-no because that has a very similar affect as an internal leak which causes high pressure CC pump to be depleted of oil & cavitate IE stop having oil available for pump to pump. The reason CC pump will pump when open center control valve lever is moved to a fully engaged position is the flow though OC valve is blocked allowing CC pump to have oil available to create pressure. Closed center valve on open center valve would cause hyd system relief valve to be unseated 100% of the time engine was operating or possibly damage pump

 

[npalen]

Open center valve utilized on a closed-center hyd system is a big no-no because that has a very similar affect as an internal leak which causes high pressure CC pump to be depleted of oil & cavitate IE stop having oil available for pump to pump. The reason CC pump will pump when open center control valve lever is moved to a fully engaged position is the flow though OC valve is blocked allowing CC pump to have oil available to create pressure. Closed center valve on open center valve would cause hyd system relief valve to be unseated 100% of the time engine was operating or possibly damage pump

Open center valve utilized on a closed-center hyd system is a big no-no because that has a very similar affect as an internal leak which causes high pressure CC pump to be depleted of oil & cavitate IE stop having oil available for pump to pump.

I'm not understanding this as it sounds like you're describing a leak in the suction line not allowing sufficient fluid into the pump causing cavitation. That would be true with either type of valve, no? (I may be misinterpreting.)

 

[Tx Jim]

Not a leak in CC suction but similar to large leak of internal high pressure oil causing main CC hyd pump to exceed it's oil supply furnished by trans pump.

Open center valve attached to closed center allows hyd oil to flow continuously which defeats the designed operation of closed center hyd system which is to build system pressure then main hyd shaft keeps turning but pump stops pumping until a hyd function is utilized then main hyd pump begins pumping again.

Normal closed center control valve stops hyd oil travel at valve until control valve is activated. That's one of the reasons a closed center control valve can attached by Teeing into hyd system but one can't successfully tee a control valve into open center system. Open center valve must be attached to hyd system in series not parallel.

 

[Tx Jim]

We can't solve Jimmy_G's tractors hyd problem until he reveals whether his tractors serial # is below or above 266,750

 

[LD1]

Seems alot of people don't understand a CC system.

It's alot like compressed air in your shop if you have a shop plumbed and several drops.

Anywhere in the system you can hook in a tool and have pressure. Because the air cannot escape the system....pressure builds....compressor quits pumping until you start using air.

Now have an open line....representing an open center system. It will never build pressure...compressor will run 24/7 and never build pressure.

This is why the OP's 3ph don't work. If it's closed center and his valve is open center.....it will NEVER build pressure until he deadheads a loader function like curl back and keep holding.

But until the OP ever reports back with a serial #, we just don't know

 

[Tx Jim]

LD1
I think that was a very good simplified explanation for operation of closed-center hyd system. In the past I've compared CC hyd system operation to shallow water well pump/pressure tank system. Water pump builds pressure in tank then switch cuts pump off until pressure in tank drops then switch turns pump on. Large water leak causes pump to operate continuously.

I was employed by JD dealer from '66-'87 which was a large portion of the ''main hey day of CC hyd's'' & served as a dealer service manager for the last 13 yrs helping technicians solve CC hyd system problems.

IMHO the main key to solving CC hyd problems is performing very good diagnostic procedures.

 

[LD1]

IMHO the main key to solving CC hyd problems is performing very good diagnostic procedures.

That is the main key in solving any hydraulic problem whether it's open center or closed

 

[npalen]

I like both, the shop air system and well pump system, as analogies for the closed center hydraulic system. The swash plate and pistons are at the heart of the operation.

Thinking back to the late sixties/early seventies, Cessna Hydraulics in Hutchinson KS was building a piston pump developed by Algear (Oilgear?), a German company IIRC. I didn't at the time realize why all the excitement for this "new pump" but I'm now wondering if it was a forerunner to modern day hydrostats. I believe they eventually abandoned the project as they found the cost to build excessive due to the tight tolerances required. Anyone know the history?

Edit: Perhaps the hydrostatic drive was first used by the Germans in the Panzers?

https://tanks-encyclopedia.com/ww2/****-germany/panzer-iv-mit-hydrostatischem-antrieb/

 

[Tx Jim]

I like both, the shop air system and well pump system, as analogies for the closed center hydraulic system. The swash plate and pistons are at the heart of the operation.

JD closed center hyd's on tractors built from '61-'92 do not utilize a swash plate. Those systems utilize a stroke control valve to control pumping. When stand-by pressure(2250 psi) is achieved stroke control valve opens diverting pressure oil to crankcase of main hyd pump pushing pistons away from rotating shaft which causes pumping to cease. When pressure in system drops then springs push pistons down against rotating shaft then pumping commences.

 

[Tx Jim]

That is the main key in solving any hydraulic problem whether it's open center or closed

I may be prejudice but I think good diagnostics is more important diagnosing closed center hyd's because JD CC hyd's is understood by a smaller percentage of people

 

[LD1]

I may be prejudice but I think good diagnostics is more important diagnosing closed center hyd's because JD CC hyd's is understood by a smaller percentage of people

You may be correct. But it seems hydraulics in general are understood by by a very small percentage of people.

 

[LD1]

For me....closed center is easy. Being able to simply tee everything....

You either have oil pressure or you don't. Sure there are wildcard cases like this where one uses a wrong valve.

But in open center stuff.....I thing there is a very very small percent of people that truly understand PB and how it functions.

I think everyone's natural instinct is to plumb as if it was CC (or like they would shop air). Just tap a pressure like somewhere and install valve. Hard to get people to understand and grasp the concept of PB

 

[npalen]

JD closed center hyd's on tractors built from '61-'92 do not utilize a swash plate. Those systems utilize a stroke control valve to control pumping. When stand-by pressure(2250 psi) is achieved stroke control valve opens diverting pressure oil to crankcase of main hyd pump pushing pistons away from rotating shaft which causes pumping to cease. When pressure in system drops then springs push pistons down against rotating shaft then pumping commences.

That's interesting! Any online animations showing how this works?