How to float my hydraulics - JD 4520

[WANNAFARM2]

Hello all.

I have a John Deere 4520 with one set of rear hydraulics that are controlled via the push button on the loader joystick. Anyone know how to make my hydraulics float so I can run my log splitter on the back? Thanks.

 

[Tx Jim]

Float position WILL NOT power a log splitter or any other type hyd apparatus.

 

[J_J]

Your hyd appear to be closed center, so your log splitter valve has to be closed center.

Just parrallel your closed center with your other valves. Add a tee at the input to your remote valve and add a QD.

The OUT from the log splitter can go to any return hose or to tank.

John Deere 4520

Hydraulics:
Type: closed center
Pressure: 2250 psi [155.1 bar]
Valves: 1 to 3

 

[jenkinsph]

Your hyd appear to be closed center, so your log splitter valve has to be closed center.

Just parrallel your closed center with your other valves. Add a tee at the input to your remote valve and add a QD.

The OUT from the log splitter can go to any return hose or to tank.

John Deere 4520

Hydraulics:
Type: closed center
Pressure: 2250 psi [155.1 bar]
Valves: 1 to 3

The early model larger 4520 uses a closed center system, the present 4520 compact tractors are open center.
I agree that float is not going to run the hydraulic log splitter.

 

[kennyd]

As mentioned, float will not help you. But what others have not written is why: Float is the absence of pressure or flow in a circuit, when active the ports in the valve are open to the tank so fluid can flow freely through the valve allowing the cylinder to move in and out, it's most often used on a loaders lift/lower circuit to allow the bucket to follow the contour of the ground. So, what you need is a way to keep the electric/hydraulic valve (EHV) energized since you only have momentary switches, but JD did not intend the EHV's to be energized for extended periods of time, that's what they sell the Power Beyond kit for-it provides a constant flow of hydraulic fluid to a implement with its own valve like your log splitter (or a backhoe). You could tap into the wires for the EHV and add in a on/off switch, but I'm not sure of the long term repercussions of that would be.

And just to clear up any confusions, your 4520 has an Open Center hydraulic system.

 

[RedHawkRidge]

Sorry if my comments take the subject off in another direction, but --
my problem with the I hydraulics off the back end (not optional but a feature that JD puts on the 4520 whether you want it or not) isn't that it won't release pressure, but rather that it continuously operates at full pressure -- no modulation. When I touch the controls on the FEL joystick, it causes my rear blade to move at warp speed. Makes adjusting the angle of the attachment rather difficult (an understatement...).
I have tried to slow down the movement by inserting a plug in the line behind one line connector with a orifice that is 1/3 the size of the line. It had effectively no effect. The only way I can reduce the movement of the implement (a rear blade) is to throttle back the engine to idle speed. That isn't an efficient method while working with the rear blade.
I decided on the plug approach after considering inserting a needle valve on the line to control the hydraulic flow, which would require high cost and result in a long extension of adaptors etc sticking off the back end of the tractor. But if the simple flow reduction of the drilled out plug didn't have a desired result, then a variable control (needle valve) wouldn't help either. Or am I missing something in addressing this issue?
jim

 

[kennyd]

Sorry if my comments take the subject off in another direction, but --
my problem with the I hydraulics off the back end (not optional but a feature that JD puts on the 4520 whether you want it or not) isn't that it won't release pressure, but rather that it continuously operates at full pressure -- no modulation. When I touch the controls on the FEL joystick, it causes my rear blade to move at warp speed. Makes adjusting the angle of the attachment rather difficult (an understatement...).
I have tried to slow down the movement by inserting a plug in the line behind one line connector with a orifice that is 1/3 the size of the line. It had effectively no effect. The only way I can reduce the movement of the implement (a rear blade) is to throttle back the engine to idle speed. That isn't an efficient method while working with the rear blade.
I decided on the plug approach after considering inserting a needle valve on the line to control the hydraulic flow, which would require high cost and result in a long extension of adaptors etc sticking off the back end of the tractor. But if the simple flow reduction of the drilled out plug didn't have a desired result, then a variable control (needle valve) wouldn't help either. Or am I missing something in addressing this issue?
jim

That is a problem with EHV's-you cant feather them. Generally a fixed flow restrictor has a .031" hole in it to slow the fluid down, not "1/3 the size of the line". You can contact Brian at Fiterite Hydraulics for some, he is an advertiser here on the forum. And yes, this is off the main topic of this post...

 

[J_J]

Since we now know the pump is an open center hyd system, the fluid will flow through all valves to tank.

If you were to put any reduction orifice in the path, it will slow down the flow.

If you install a needle valve in the remote valve work port flow path, and turn it in, it will slow the fluid all the way to stop, whereby the pump fluid will pass through a relief valve.

So the answer is, it will slow down the GPM's to the cyl, and therefore less speed.

 

[MorningViewStables]

Hello all.

I have a John Deere 4520 with one set of rear hydraulics that are controlled via the push button on the loader joystick. Anyone know how to make my hydraulics float so I can run my log splitter on the back? Thanks.

That feature is referred to by John Deere as PowerBeyond. You need to check with JD to see if there is a kit for your 4520 to add the feature.