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Central New York | I'm having these symptoms on my 3588 after running it on a chisel plow we borrowed for a few hours. The next day I started the tractor and after about 15 minutes the hydraulic pressure warning light started to flicker and then eventually came on solid. I checked the transmission oil and found it low (bottom of the stick) so I filled it but the light stayed on. I then tested in the driveway and found that while the TA would shift between low and high, if it was in high and I lightly pressed the brake it would drop to low, the shift to high as soon as I took the brake off.
The next day after talking with my local dealer I replaced the hydraulic filters and added an extra 5 gallons of oil. Started the tractor and the light went out after the system primed and charged. Same thing occurred - after about 15 minutes of running (not under load - just down the road to get hooked up) the light came on and the TA acted the same way. I ran the tractor on the disk for a couple of hours in low TA with no problem, but the light stayed on and I noticed that the tractor would freewheel to some degree going downhill on the road.
So my question is: are these all symptoms of the TA needing to be replaced, or is the TA behaving this way because of another problem related to low hydraulic pressure on that circuit? We've had the tractor for around 10 years using it for moldboard plowing and disking. It's not turned up.
One other thing - when the light comes on it stays solid in low or high, but goes out when the lever is in between low and high.
The tractor probably has close to 10,000 hours on it. We've never changed the TA and I don't know if it was changed in the past.
I don't want to replace the TA only to find that the issue is pressure related and have it not be resolved.
Thanks in advance.
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owego ny | There is a flow divider in the multiple control valve that is possibly stuck its up above the small plug on the back side facing rear of tractor |
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Central New York | Is that something I can take out and clean? Or does it need to be replaced? |
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owego ny | Yes pull out plug believe the head is one inch spring comes out reach in with a pick to pull spool may have to leave plug out and start tractor and have hyds push it out if it's stuck. Also take out the small plug underneath it there is a orfice in there it unscrews make sure it's clean. |
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NC IA | I'm a novice (not an expert) on 2+2s.
How dirty were you filters when you changed them? If I remember right, they have half-size hydraulic filters for the goofy extra pump for the steering. (I do believe the pump in the trans brake housing is separate for steering.) So I assume you have no steering issues with loss of TA pressure.
That is not good for the TA running it with the light on. That means no lube pressure for the TA. It will (should) pull itself in low side with no oil pressure (still not good, no lube), but if you try running it in the high side with low or no lockup pressure you will (if you allready haven't) smoke the high-side clutch pack.
Maybe try changing filters & filter o-ring one more time?
I'd bet you need a mcv pump/mcv body overhaul/TA job.
Does the hitch pump seem to work fine? |
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Central New York | Thanks I will give that a try when I get home tonight. I'm going to check other sites online to make sure I'm working on the right thing.
We've always treated the TA carefully and from what I understand when they fail they tend to stop working in the low range first. My neighbors has been running his in high for the past couple of years because of this. |
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Central New York | They did not seem overly dirty; the screens were very clean with only a few particles on them. The tractor has two filter elements with metal screens behind the pump intake elbow that is located ahead of the right axle housing. It also has one spin on filter ahead and above of this intake that according to the dealer is for the 'priority hydraulic system' or something like that.
No loss of of service on brakes, steering, 3point hitch, or auxiliary valves. The tractor does not have a trans brake.
The two dealers I talked to said that they didn't think any damage would happen from running it in low - in effect whatever damage was done was already done and that I wouldn't damage anything else besides the TA if I did this. I'm in a bit of a bind as this is the only tractor I have with enough traction to pull the disk and packer.
There were no o-rings on the filters, even though some came with the new ones. They just went onto holders with the only o-ring being on the intake elbow where it bolted back on.
Agreed about running it in high - I'm leaving the lever in low until I can get this resolved.
It seems to me that if the MCV pump was weak I would be seeing it in the steering or brakes not working well, wouldn't I?
Edited by cact34r 5/25/2017 13:13
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Grand Island, Nebraska | From what you describe my thoughts indicate a TA that has a hydraulic leak and is in need of replacement. When you put the TA lever in mid position you are blocking oil flow to both low and high circuits in the TA. You need to have a thorough hydraulic pressure and flow test done before proceeding further.
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| If your red light is on, I would not run it. That means you have no lube for anything else in the transmission |
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Central New York | scottpf - that's what I thought too, but the technician I talked to at the dealer (who has always been very good) told said that the light isn't a true hydraulic pressure light, that's its only for the TA which I don't understand but was hoping it to be true. The owners manual says to see your dealer if it comes on, but does not say 'do not operate while on'. When I see red lights I typically stop. |
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Central New York | I think that's the way I was leaning as well, but I don't know how they work and wasn't sure if that was a typical failure mode. |
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Central New York | Would it be wrong to think that running with the TA lever in between the two positions would be better than running it in low with the warning light on? If the TA is leaking and dropping the pressure in the trans lube pressure circuit, would shutting off both high and low let me operate the tractor and still provide lube to the rear? Realizing this is not doing the TA any favors.
Or does that shut the oil off for everything when it's in between high and low? |
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Upstate Ny | My experience is if you have changed the filter and pressure is fine when cool, and not so good when hot it's a sign the pump is getting out of tolerance. |
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NC IA | DO NOT run with the TA lever in the mid position.
Another thing is to check the dump valve linkage to make sure its not stuck open, its on the back side of the MCV behind the left battery.
I "think" the steering is ran of a separate pump on a 2+2, not from the mcv pump as on a 2wd. You would still have brakes if the mcv is weak, because brakes have priority, it will give pressure to power brakes first, this why your TA is "downshifting" when you step on the brakes (indicating a big internal leak as mentioned above, or a weak mcv pump.)
What do you mean by it "does not have a transmission brake?"
If your mcv pump is totally crapped out, you will not be getting lube to your ring & pinion.
If you are dire emergency must run this tractor, make sure it is AT LEAST 5 gal over-full on hydraulic oil.
"run at your own risk!" |
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Central New York | Ok I was just wondering - I won't run with the lever in between high and low.
regarding the transmission brake - I thought that was the brake that stopped the gears from spinning when you pushed the clutch in so that you could shift sooner than waiting for them to spin down. I thought the 6xxx series had that but not the 3xxx series. if there is another type of transmission brake I don't know what it is.
I understand what you are saying about the other. I'll check now that I'm home from my other job. |
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NC IA | cact34r - 5/25/2017 16:57
Ok I was just wondering - I won't run with the lever in between high and low.
regarding the transmission brake - I thought that was the brake that stopped the gears from spinning when you pushed the clutch in so that you could shift sooner than waiting for them to spin down. I thought the 6xxx series had that but not the 3xxx series. if there is another type of transmission brake I don't know what it is.
I understand what you are saying about the other. I'll check now that I'm home from my other job.
ALL large frame, gear drive (non-hydro) tractors 706 through 1586, and the 33-35-3788 2+2s had mechanical linkage transmission brake. (Bottom cover of speed transmission/TA housing.) 30-32-3688 and 63-65-6788s had same transmission brake, only hydraulic actuated. Your steering pump is mounted to this bottom cover that I speak of, and I believe that is a 2+2 only thing (the separate steering pump.)
If you said the hyd oil was on the "add" mark, that is 5 gal low. So to get it 5 gal over-full, you need to be adding 10 gal from when it originally was on "add." |
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Southeastern Tipton County, Indiana | cact34r - 5/25/2017 14:11 They did not seem overly dirty; the screens were very clean with only a few particles on them. The tractor has two filter elements with metal screens behind the pump intake elbow that is located ahead of the right axle housing. It also has one spin on filter ahead and above of this intake that according to the dealer is for the 'priority hydraulic system' or something like that. No loss of of service on brakes, steering, 3point hitch, or auxiliary valves. The tractor does not have a trans brake. The two dealers I talked to said that they didn't think any damage would happen from running it in low - in effect whatever damage was done was already done and that I wouldn't damage anything else besides the TA if I did this. I'm in a bit of a bind as this is the only tractor I have with enough traction to pull the disk and packer. There were no o-rings on the filters, even though some came with the new ones. They just went onto holders with the only o-ring being on the intake elbow where it bolted back on. Agreed about running it in high - I'm leaving the lever in low until I can get this resolved. It seems to me that if the MCV pump was weak I would be seeing it in the steering or brakes not working well, wouldn't I? There is not a pump mounted to the MCV on a 2+2, oil from the steering pump is sent to the MCV and is ported through a block that mounts where a pump would be on a regular large frame Farmall.
Edited by Jim Naden 5/25/2017 20:59
 (2+2 MCV.jpg)
 (2+2 TA hyd circuit.jpg)
Attachments
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 2+2 MCV.jpg (78KB - 135 downloads)
2+2 TA hyd circuit.jpg (89KB - 151 downloads)
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Central New York | Update for tonight - thank you for all the information provided so far. I'll try to answer the questions above.
First - I went over after work and started the tractor to move it near the shop and pressure washer. 1st I verify that the dump valve rod is connected and working properly. Then, cold start and I have no warning light and the TA works normally. In 3rd low with the TA in high I can step on the brake to the point the tractor almost stalls and it does not drop to low. Shifting high to low works normally. Would this be possible if the TA was failed? It seems that if it was leaking oil internally from a seal it would do it regardless of temperature.
After the wash by the time I move it near the shop the light is starting to flicker in high. Attach a pressure gauge to the sensor port and restart the tractor and see 10psi in high and low. Stepping on the brake drops the pressure to a hard 0. Putting the handle in between does not measurably raise or lower the pressure.
Next I pull the flow divider spool per gd856. The spool is not stuck but is a little sticky and not smooth. The spring is on the inside (farthest away from the plug that holds it in). The spool shows some light scoring and I can't tell if the hole in the end of the spool has oil in it or a piece of debris. I haven't found the small plug underneath it yet. I will finish that and test after I put the spool back in; should it be lightly sanded with 400 to smooth it up?
I will also check the pressure in the morning when everything is cold again, but it did not take much warming to bring the light on and shut down the TA.
jalopy - thanks for the information about the transmission brake and the MCV pump. Maybe I can adjust it to help with shifting out of neutral - I did see an arm in that MCV pump area and wondered what it did. Also - the oil level was at the bottom of the stick, not the bottom of the add line (my fault). It took about 7 gallons to bring it up to the full mark, and I've added 5 additional gallons over that. I won't run it unless I have to, but I've got nothing planted yet due to weather.
Jim Naden - I'm a little confused by what you wrote. If the steering pump on my tractor was weak and it supplies oil to the MCV would I also notice steering and/or brake weakness? I understand there isn't a pump mounted to the MCV and see the steering pump under the tractor. Thank you for the diagram and the other page - I've ordered a service manual but it's not here yet. Since my steering, brakes, and seat are working normally that would lead me to think the pump is ok?
I've attached pictures of the pressure at idle and 1800rpm and also a picture of the spool valve.
 (IMG_5794.JPG)
 (IMG_5793.JPG)
 (IMG_5797 2.JPG)
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IMG_5794.JPG (116KB - 107 downloads)
IMG_5793.JPG (136KB - 107 downloads)
IMG_5797 2.JPG (81KB - 97 downloads)
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NC IA | Jim Naden - 5/25/2017 19:34
There is not a pump mounted to the MCV on a 2+2, oil from the steering pump is sent to the MCV and is ported through a block that mounts where a pump would be on a regular large frame Farmall.
Okay this proves I'm a novice and not an expert in 2+2s like I said. I learn something everyday. I've done several rear-end jobs in a 35 & 37 years ago, but honestly never have done a TA or MCV job on a 2+2. I just knew they had an external pump under the speed trans, but I thought it was dedicated to steering. Thanks for correcting my assumptions with facts! |
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Central New York | looking at the pictures I uploaded I think I need to get a different gauge - I think that's reading 20psi, not 10. when it's warm and the TA is not working. |
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Southeastern Tipton County, Indiana | cact34r - 5/25/2017 22:34 Update for tonight - thank you for all the information provided so far. I'll try to answer the questions above. Jim Naden - I'm a little confused by what you wrote. If the steering pump on my tractor was weak and it supplies oil to the MCV would I also notice steering and/or brake weakness? I understand there isn't a pump mounted to the MCV and see the steering pump under the tractor. Thank you for the diagram and the other page - I've ordered a service manual but it's not here yet. Since my steering, brakes, and seat are working normally that would lead me to think the pump is ok? I've attached pictures of the pressure at idle and 1800rpm and also a picture of the spool valve. The spool you had out is the pressure regulator, located at the top of the MCV. You need to remove the flow divider, item 8 in the attached illustration. Behind the 1" hex plug. If it is stuck it can cause the exact symptom you describe. The one advantage of a 2+2 with the large external steering pump is there was rarely TA problems caused by low pump flow. IIRC the lube warning switch closes when the pressure drops to 8 psi.
Edited by Jim Naden 5/26/2017 04:59
 (MCV TA Spool Identification .jpg)
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MCV TA Spool Identification .jpg (31KB - 163 downloads)
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Central New York | Thanks for that - I see that now too. I will pull the flow divider tonight after I test when cold using a lower scale gauge.
Do MCV's wear out and require replacing as a unit? The marks on the spool for the regulator are deep enough to catch on a fingernail. Is it probably safe to say that the bore is marked too?
I appreciate the info on the trip pressure for the switch. What should the pressure be?
Appreciate the diagram - that is even more detailed than the other one above. |
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Southeastern Tipton County, Indiana | cact34r - 5/26/2017 10:10
Thanks for that - I see that now too. I will pull the flow divider tonight after I test when cold using a lower scale gauge.
Do MCV's wear out and require replacing as a unit? The marks on the spool for the regulator are deep enough to catch on a fingernail. Is it probably safe to say that the bore is marked too?
I appreciate the info on the trip pressure for the switch. What should the pressure be?
Appreciate the diagram - that is even more detailed than the other one above.
I have never replaced an MCV in 41 years as a dealership technician. There can be some problems with bore wear that could necessitate replacement.
I wouldn't worry too much about those marks but I would lightly smooth it with 400 paper. Be careful to not round over the corners of the lands on the spool.
Lube pressure should be in the 18-22 psi range. |
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Central New York | Tonight was simply an exercise in frustration. Before I could test with the lower scale gauge I had to reinstall the pressure regulator spool. After fighting it for an hour and a half with various types of tools I've come to realize that I'm going to have to remove the battery box and cab steps to be able to get that back in there against the spring without cross threading it. I will post back when I get it in and tested, and also after I check the flow divider. Jim thanks again that's very helpful information. |
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Central New York | Update - over the past 2 days I reinstalled the pressure regulator after pulling off the battery and step to get the right leverage. Then removed the flow divider spool which did require cranking the tractor to push it out. Everything looked good in there. Also removed the plug over the orifice but didn't see what was supposed to checked in there. The plug had a little thing in the middle of it, but inside the MCV there wasn't anything I could see. I've put a picture of the plug - is this normal? It was hard to get it in focus but there was a little piece of metal in the hole, almost like a ball but it didn't move.
After I put it back together I started it with the TA in high and ran it at a fast idle without touching anything else. Using a lower scaled gauge it started out at 17 psi when everything was cold and gradually over the next 20 minutes dropped to 5 psi. At this point touching the brake pedal or the differential lock foot switch would drop it to zero and it would recover back slowly to 5 psi after it was released. Moving the TA lever to low would drop the pressure to 3 psi.
I then moved the handle to in between low and high and the pressure went immediately to 22 psi. Would that indicate the TA has a failure in it?
 (IMG_5827.JPG)
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IMG_5827.JPG (86KB - 118 downloads)
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Central New York | Update - I sent the tractor to the dealer for repair for what appears to be the TA. Will post back with final results. |
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Central New York | Here's an update - was just reminded that I never left one. Dealer picked up the tractor and called a few days later to say the TA needed to be replaced. I had it done with a HyCapacity unit and had the clutch done at the same time. I asked if it wore out or if I harmed it running it low on oil and the service manager said probably both - in his experience they tend to last around 5-6,000 hours. I got the tractor back about a month later and missed it during spring tillage; the Case 2394 had plenty of power but nowhere near enough traction. Have been using it for the past 3 seasons and working great. If it happens again I hope I can do it myself - the bill was over 10k. |
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IH 3588 hydraulic warning light, TA issues help (details)
