2040 hydraulic problems

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Big Tomm

New member
After the hydraulic oil on my JD2040 gets hot I start having hydraulic control problems. I was told I have a valve problem. Is this a check valve? Do I have to separate the tractor to repair . Could It be something else? Should a novice try this kind of repair? Thanks

Big Tomm
 
What do you mean by hydraulic control problem? Is the three point hitch not working properly? The rear outlets? Loader? Steering? All of the above? Does it quit working when hot or is it slow? Jerky?
 
JD110, its the 3 point hook up. The response is a combination of very slow to none at all. No problems when I first start the tractor.
 
Have you replaced the hydraulic filter and cleaned the sump screen? If not, then do that first. 2040's could have two different hydraulic systems depending on serial number. Do you know what your serial number is? Does the tractor have independent pto or a hi-lo shifter on the left side of steering wheel? Your problem could be a clogged filter, bad transmission pump, a bad filter relief valve, blown orings in three point valves, or steering valve. If you have independent pto or hi-lo, you could have a leak in one of those components causing the problem. How long do hydraulics work properly on a cold start? Are you using any other hydraulic attachments like a log splitter? Lots of possibilities, some simple to fix, others are more difficult. Give us as much info as you can and we will try to narrow it down. Do you have any hydraulic test gauges?
 
JD110, the serial # is 204sa392620L. The filters are ok. I believe the tractor has an independent pto as you have described. After about 30 minuted I start having 3 point hook up trouble. The steering and brakes work fine. I have not hooked any hydraulic implement to the tractor. The tractor was manufactured in 1980. The lift will start responding slowly or not at all. I will sometimes put the tractor in neutral and increase the rpms on the engine and get a response from the 3 point lift. I hope this helps. Thanks in advance for the advice.

Big Tom
 
That serial number definitely has closed center hydraulics. There are still several possibilities. First, try starting the tractor and leave it run at 1200 to 1500 rpm for maybe 10 - 15 minutes without touching steering wheel or any hydraulic functions. Then feel the steering valve/column, three point hitch housing and rear scv valve housing for heat. The three point housing would heat up on right front corner, under your right leg as you sit in the seat. Any item that is warm or hot to the touch has an internal high pressure leak that is robbing the hydraulic system of oil. If nothing heats up, then you have a problem on the low pressure side of the system - transmission pump worn, filter relief valve stuck open, broken or cracked internal oil lines, or leak in pto clutch or brake. On these tractors, the transmission pump supplies lube oil to transmission, pressure oil to pto clutch and hi-lo if equipped, and all the left over oil supplies main hydraulic pump with oil for steering, three point and scv operation.
 
Not intimately familiar with this particular tractor. Does it have a flow control valve for the 3 point hitch?
 
Flow controller

Doc, I do not know if it has a flow controller or not. What I do know is that I referred to a manual and it said you should be able to lift from ground to max lift in a certain amount of time. (2-3 seconds I can remember). I tested my tractor and it was right on. The problem comes in after the tractor heats up.


Big Tom
 
Which was better? I forgot, I know I have the better kind, my cousin has the other kind, Closed center or open center? Where is the sump screen?
 
I know it's been awhile since anyone posted on this subject.
I also have a JD 2040 that has blown out the 3/4 hydraulic reservoir hose 3 times. John Deere says the replacement is a 3/4 inch auto heater hose. Each time I was operating the hydraulic remote system with either a haybine or a V-rake.
Mine is a closed system. Is the heat that is generated in a close system enough to blow out this return line that attached to the top of the hydraulic reservoir tank?
Thanks, Mark
 
A 3/4" automotive heater hose will NOT last for this purpose. The heater hose is not designed to withstand oil or pressures that can exceed 150 psi. Your dealer should have some hose under part number TY22329 that he can cut a piece to length for you. It is similar in appearance to heater hose, but it is stronger and is made of a different material to withstand oil.
 
jd110,
Thanks for the info!
I called the local dealer and they do have that P/N in stock. I wonder why they didn't offer that P/N before?
Mark
 
JD110,
Now I see why! I picked up the hose you told me to. Regular old heater hose is only good to 50 psi.
John Deere P/N TY22329 has 300 psi printed on it.
Thanks again, Mark
 
Hello Gang...I have a hyd problem with my 2040.While running my bush hog I hit a stump and sheered a pin.I raised the hog and went to the house and lowered the hog..replaced the pin but when I tryed the lift it would not raise and the power steering was also not working.I have replaced filter,cleaned screen,removed all check valves on the outside of the tractor per the maint. manual.All look good with no metal or damage.The hyd fluid looked a little milky but was clean.Have not run a pressure or flow check...Thats next....No unusual noise anywhere.Questions are ...where to look next...how do you get to the trans. pump...Where would you look 1st for a cracked or broken line inside the tractor.......Thanks.........
 
This is directed to jd110, if still active, I do have a 2040 w/closed center hyd sys, in following your test of running for 10-15 minutes, the only warm part that I have is at the base of the steering cyclinder, it gets 20 degrees warmer than the mounting point. Lower part of engine block at 90 F and base of steering cyl at 107 F. Is this a serious issue? Just finished replacing all seals and gaskets in the steering cylinder. Thanks
 
I would say it's probably not a serious problem unless you now are experiencing OTHER hydraulic issues as well. What brought you to the conclusion you needed these seals replaced to begin with, and what, if any, other symptoms were present in the hydraulic system? You stated "replacing all seals and gaskets". Does that include the control valve seals or just the piston/cylinder? Also a bit confused about the term "lower part of engine block" and how that relates to the steering column.
 
Hello Feduup, I was having extreme hydraulic oil heating problems, steering cylinder getting to hot to touch. When I disassembled the cylinder the steering valve o-rings were abraided. The temperature of steering cylinder was 195 F while ambient temp was 94 F while running a hay mower. Then all hydraulics got slow and unresponsive. " lower part of engine block" is where the steering cylinder attaches to tractor. The transmission pump was replaced prior to this by my local JD dealer, then I replaced the front Hyd. pump about two weeks later. Regards
 
I guess my question is do you think you still have issues somewhere in the system?

I can understand the pumps being replaced, okay, but was the heating (or any other symptoms) in the steering valve considered in the decision to replace the pumps or was that only discovered later? It wouldn't be the first time pumps were replaced when the cause of the problem is actually elsewhere.

If you have doubts about the steering valve and possible internal leakage , I would think if you remove the cover on the right side that exposes the pin at the bottom end of the steering cylinder rod you should be able to see oil from the valve above leaking down with the engine running and the steering valve in neutral. You should be familiar with all that if you just had the valve all apart. The absence of fluid there would be a good indication that what you did on the valve was done correctly.
 
This was the first run up since I rebuilt the steering cylinder, prior to rebuilding the temperature rise was much higner. In the process or the rebuild I found the O-ring at the bottom of the gland for the piston rod was missing. This unit was replaced five years earlier, it was a rebuild unit from an aftermarket supplier. That was the beginning of all the rest of the hydraulic issues, Had to replace seals and O-rings in the 3-pt rockshaft it had fluid running out of the cylinder in a stream. I think that many on the prior problems have not been resolved. I will get another side cover gasket and perform your suggested inspection for a leak. The steering wheel stays centered now at engine speed and does not creep to the right like it did before rebuilding the steering cylinder. Thank you for answering with a good suggestion. By the way I am getting ready to overhaul the rear service control valve next due to creep when in use. I have the JD Technical Manual which goes into great detail on that part. Regards.
 
I'm not suggesting you pull the side cover just for a look/see, only that it might be something to consider if you still have problems elsewhere that don't make sense. I've never paid much attention to temperature differentials except when search out problems, so I won't say that a few degrees of difference is a major concern at this point. If it all seems to be working, then run it.

Just an aside here, but how did you make out installing the six O rings in the column that seal the control valve spool sections?
 
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