Open Center vs Closed Center

[Oiltech]

How do I determine what design hydraulic system is on my tractor? It's a Kubota M7060 HDC12.

 

[Peter 315]

open center........

 

[RickB]

It is indeed open center.

 

[Tx Jim]

X3 open center. Majority of tractors have open center hyd's because open center hyd system is less expensive to build & less complex to diagnose if problems arise.

 

[Tinhack]

Ditto on that. Closed center systems require all manner of gismos and whatnots. If the pump is pumping, the oil has to go somewhere. :laughing:

 

[Zebrafive]

Tractordata.com will tell you. All replies are same too :thumbsup:

 

[Tx Jim]

Ditto on that. Closed center systems require all manner of gismos and whatnots. If the pump is pumping, the oil has to go somewhere. :laughing:

If JD closed center hyd system is operating correctly when stand-by pressure is attained with no internal/external leaks hyd pump shaft continues to rotate but pistons are forced away from shaft by pump crankcase pressure therefore causing hyd pump to stop pumping oil

 

[Tinhack]

Yeah, that type of pump falls into the "gizmo" category.

 

[RickB]

Yeah, that type of pump falls into the "gizmo" category.

That type of pump set John Deere apart from the rest of the Ag Equipment industry and was a major factor of the company's meteoric rise to the position of North American leader which it has maintained for about 6 decades.

 

[Tx Jim]

Yeah, that type of pump falls into the "gizmo" category.

Tinhack
Just because the CC pump has a stroke control valve & inlet/outlet valves doesn't classify it as "gizmo" category to me. But I understand how a closed center hyd system was designed to function. My JD 4255 which has a similar CC hyd pump that I've owned since Feb. '93 has over 11,500 hrs on original(untouched) hyd pump that I could purchase a ""new hyd pump"" for a little over $500. Can you purchase a new hyd pump for either one of the tractors for $500? I'll bet it can't happen.
Jim