John Deere Hydraulics

Hillman

New User
I need to know if the John Deere 4230 is closed or open hydraulics. I want to add a three spool joystick via a power beyond manifold to control the 148 loader hydraulic cylinders and hay grapple and need to know if it should be an open center or closed center joystick. I am replacing all hydraulic hoses. Will these new lines need to be bled and is there a method for bleeding. Any help would be appreciated.
 
That is a closed center system. For bleed out air just keep cycling the loader up and down and dump it will work the air out. Keep an eye on the fluid level.
 

Closed centre and no need to relieve air. If there is a relief valve in the loader controls , set it to at least 2400psi.
What is the supply and return locations for the oil to supply the loader valves ?
 
Supply and return connections will be at the hydraulic manifold installed on remote at rear of tractor. This is true for a open center but not sure about closed center return connection.
 
(quoted from post at 05:35:22 08/12/17) Supply and return connections will be at the hydraulic manifold installed on remote at rear of tractor. This is true for a open center but not sure about closed center return connection.

Auxiliary hyd block(pby) block mounted between rockshaft housing & scv is the correct place to attach a closed center valve BUT there is no good location to attach an open center hyd valve on a JD 4230.
 
Hard to nail down exactly where and how the supply and return connections should be. Supply is connected in top of hydraulic manifold. I assumed the return would be in the lower side of the manifold. I understand it will be made for a closed center and opinions seems to be vary on the return connection.
 

Elbow fitting(key 6) is pressure port & fitting (key 9) is return port.

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Thanks, that is what I understand. A tech support rep at Surplus center recommended adding a tee for some reason when using the closed center plug.
 
That is what confused me! He seemed to be concerned about a closed center valve. I did not understand his concern.
 

A tee isn't required for a closed center valve for pressure or return ports. Maybe salesman was thinking about return & pby ports on an open center valve.
 
(quoted from post at 06:35:22 08/12/17) Supply and return connections will be at the hydraulic manifold installed on remote at rear of tractor. This is true for a open center but not sure about closed center return connection.

Doing it right with the manifold on the SCV .
 
Just did mine with the manifold on the scv. Works very well. Bought an aftermarket kit on ebay from a machine shop that makes them. Perfect workmanship and the kit had all of the parts - even extenders to rework the scv control rods to make them longer to reach the levers after the pyb was installed. Kit was around $170 which is much cheaper than the OEM part. USA made part.

John
 

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