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

 

[Hay Dude]

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

Nope. I did a pump and it was waaaaayyyy more than $500

 

[LD1]

People use the term gizmo when they really have no clue how something works....:laughing:

 

[Peter 315]

People use the term gizmo when they really have no clue how something works....:laughing:

Don't feed them after midnight......

 

[Tinhack]

They also use the term whatnots. An occasional whodeedo and whatchamacallit may be thrown in. But we are so blessed. There's always a few knowitalls in the crowd to help us out if we forget the name of sumthin'. :thumbsup:

 

[Tx Jim]

They also use the term whatnots. An occasional whodeedo and whatchamacallit may be thrown in. But we are so blessed. There's always a few knowitalls in the crowd to help us out if we forget the name of sumthin'. :thumbsup:

Tinhack
I served 13 yrs('74-'87) as a JD dealer service manager so I had a lot of exposure to the JD closed center hyd system so therefore I'm probably more knowledgeable on that system than the average person. If that makes me a "knowitall" so be it. I hope you have a Happy New Year.
Jim

 

[Peter 315]

Tinhack
I served 13 yrs('74-'87) as a JD dealer service manager so I had a lot of exposure to the JD closed center hyd system so therefore I'm probably more knowledgeable on that system than the average person. If that makes me a "knowitall" so be it. I hope you have a Happy New Year.
Jim

SORRY,you need 14 years to be a knowitall......:laughing:

 

[Hay Dude]

SORRY,you need 14 years to be a knowitall......:laughing:

Or 4,000+ posts :laughing:

 

[Tinhack]

Or 4,000+ posts :laughing:

 

[LD1]

They also use the term whatnots. An occasional whodeedo and whatchamacallit may be thrown in. But we are so blessed. There's always a few knowitalls in the crowd to help us out if we forget the name of sumthin'. :thumbsup:

Your post had nothing to do with forgetting names.or terminology.

You act like a variable displacement pump and closed center systems operate off some kind of magic fairy dust and unicorn farts.

Your lack of understanding how they work doesn't make those that do "know-it-alls"

I don't understand how computer software and programming works. Doesn't mean is am gonna troll the people that do, make unfounded statements, then call them "know-it-alls" when they respond trying to help one understand.