KUBOTA M120DTC Hydraulic Question

[GrayMule]

Hey guys hope all is good.
I was hoping somebody might be able to answer a simple question about the Kubota M120DTC hydraulic system...is it an open or closed system?
Most curious about the Steering Control Valve. Thanks in advance.

 

[slowzuki]

All Kubota's I know of that size are provided with a separate steering pump that is an open centre fixed displacement pump. The steering is via an orbital valve which is usually called hydrostatic power steering.

 

[GrayMule]

Since it is a fixed displacement pump, couldn't I run that valve off my FEL pump [with a priority valve, of course]?

 

[slowzuki]

Yes I suppose, this is how older single pump tractors like the Case IH 85 series etc where plumbed. The lines might be way too small though as the main pump is 3-5 times the size o the steering pump. It also sucks. You'd lose the 3 point hitch while steering, under load. The loader would stop under steering load etc.

Are you trying to avoid fixing the pump? You could put a belt driven automotive power steering pump like many Ford/NH's had in the old days. Separate reservoir but not as much flow, can't steer as fast.

Since it is a fixed displacement pump, couldn't I run that valve off my FEL pump [with a priority valve, of course]?

 

[slowzuki]

One other thing, not sure about the Kubota, but on my large MF, the steering pump also runs a bunch of the transmission functions and the wet clutch.

 

[GrayMule]

Actually, I was thinking of using the Kubota valve on another tractor for a power steering conversion. I was thinking of plumbing it off the fel pump on a priority valve, as I mentioned.
Its still just an idea at this point, but if I knew for sure it would work with what I have to work with - l would most likely do it.
The pump I have is a Cessna, I don't remember the exact flow, but it seems like it was around 11-16 gpm..planning on checking it again. I have two 17 inch cylinders with around a 1.5 bore, 2.5 dia and 10 inch stroke.
The Kubota valve I was thinking about purchasing on a fairly good deal, which led to my post. I cant find any info on the valve.[Shoot, cant hardly find anything on the M120DTC tractor, itself].
Again, I am still up in the air about it because of the little info on the valve. It looks something like a CharrLynn/ Eaton 10 series valve, but really unsure.

 

[GrayMule]

the plan would be for the pump to only power the FEL and steering

 

[slowzuki]

I'm sure you could get a conventional orbital valve for cheap, it would have a more common fitting on it too. The Kubota is likely iso or din metric fittings that are about 20$ each to do anything with. Without knowing the cc's, its hard to know the cylinder size you need.

 

[GrayMule]

yeh, I really didnt think about the metric fittings...I know of a Sauer Danfoss unit, I could get for around the same as the one off the Kubota. I will probablly go that route. Thanks Zuki, I appreciate your post. That Danfoss unit is a ospb 100..I welcome any input.