I checked relief psi today. Only about 1900. Adjusted to around 2400. I was using my neighbors gauge that god only knows how old it was. I ordered a new gauge today and when I get that in I am going to dial it in. Now the tractor is like every other CUT I have ever drove, runs out of traction before power. I am very happy with the results. Thanks for the help.
1532 Hyrostatic problem/question.
- Thread starter jmarx82
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TSO
Elite Member
Was it the same relief valve that I detailed?
k0ua
Epic Contributor
Hmmm... My Kioti workshop manual say 4975 psi.. Our tractor sizes are similiar I would expect something over 4000 PSI. Where and what did you measure? You do know we are not talking about the implement hydraulic pump, but the Hydrostatic drive pump itself. There is usually a special port on the side of the transmission to measure this hi pressure. This is also not to be confused with the charge pump pressure, that is usually a few hundred, Mine is 255 psi. I am assuming you have a workshop manual for this machine. I would not attempt it without it. You say you notice and improvement, but I am a bit confused at the pressures you quoted. I though all hydro trannies operated in this 4000+ area, and the larger they get the higher the pressure. But I could be wrong, I have been before.
Yes, I found that that relief valve takes care of the whole system, but I did see another one on the 3 point. I had to break the paint like you explained in your thread. I took the valve out, cleaned it up and started at 0 psi. When the screw was all the way out, nothing worked.
TSO
Elite Member
Hmmm... My Kioti workshop manual say 4975 psi.. Our tractor sizes are similiar I would expect something over 4000 PSI. Where and what did you measure? You do know we are not talking about the implement hydraulic pump, but the Hydrostatic drive pump itself. There is usually a special port on the side of the transmission to measure this hi pressure. This is also not to be confused with the charge pump pressure, that is usually a few hundred, Mine is 255 psi. I am assuming you have a workshop manual for this machine. I would not attempt it without it. You say you notice and improvement, but I am a bit confused at the pressures you quoted. I though all hydro trannies operated in this 4000+ area, and the larger they get the higher the pressure. But I could be wrong, I have been before.
The overall system pressure on my Massey is supposed to be around 2500 ... I'll have to check the manual for specifics but it's definitely not 4000 !
murphy1244
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My DK is 4975 psi.
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I measured at the FEL output like TSO described in his thread about checking the psi at the loader. On the Massey, it looks to me that one pump is for the system, and one for steering. If you follow the lines, it goes from the pump, to the relief valve. Then a line runs off this to the HST. The FEL valve is piggybacked on the relief valve block(I don't know the technical term for this and I am just calling it like I see it), and I am sure there is some internal passages to get the the fluid where it needs to go.
k0ua
Epic Contributor
I just don't see how changing the relief pressure on the implement pump has anything to do with setting the relief pressure of the Hydrostatic transmission. I agree that the implement pump has two sections, one for the FEL/3pt/remotes. And one section for the power steering.. But neither has anything to do with the Hydrostatic transmission relief valve. or its pressure, which for that size tractor would be well over 4000 psi. near 5000.
radrock
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I haven't been on this post for awhile. I think you are correct on that pressure. I had loader/three point hitch issues when I first got my tractor and it was due to incorrect pressure relieve valve setting on the loader valve. I watched the guy doing it and it was between 2400-2500 when he shimmed up the valve. I'll have to try and find that link for that hydrostatic relief valve for future reference as mine seems a little sluggish but not horrible.
k0ua
Epic Contributor
We are discussing two different things.. Yes I can easily believe the 2500 for your implement hydraulic pump. I think mine on the Kioti is about 2645 or something similar. But I was talking about the Hydrostatic transmission pump relief pressure, which I believe should be just under 5000 psi. Mine is stated to be 4975 psi in the workshop manual.
TSO
Elite Member
This is from my tractor manual (not loader manual). Actually has total system pressure at 2276. My loader manual states 2500 (but I'm thinking that's just the number they list for the posted specs, and not necessarily where the pressure should be set.
There is no other PSI rating listed in the manual besides steering (1711), so it must be right.
TSO
Elite Member
k0ua
Epic Contributor
Agreed, but that has nothing to do with the relief setting on your hydrostatic transmission. You need to look in your workshop manual for these settings and port measuring locations. This will not be found in any makers owners manual.. As it is not something for owners to either measure or adjust.
TSO
Elite Member
So, just to verify, you're saying that by adjusting the relief valve that I detailed ... Which adjusted my loader lift ... Fixed the issue you were having with your HST?
IF that is the case, then it would seem appropriate to believe that this valve handles the loader AND HST system.
It's also possible that somehow there was air in the system, and opening the relief valve bled it out and fixed your HST issues. Long shot, but possible.
radrock
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tman1020
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At What rpm did you run your test at?
k0ua
Epic Contributor
There you go George, you hydrostatic transmission pressure relief is set for 3336 PSI. This has nothing to do with the pressure relief setting for the implement pump. that pump is the little pump up on the side of the engine. The hydrostatic transmission pump is one of the two main components of a hydrostatic tramsmission. One being the pump and the other being the motor. The pump is driven by the engine.
murphy1244
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James why you spose they are so different?
k0ua
Epic Contributor
The bigger the tractor the higher the pressure the hydrostatic pump has to be to move the tractor around.. Up to a point anyway.
murphy1244
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Makes sense. So TSO's tractor is up there with ours then? or more. Man 4975psi is a lot of umpa.
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