JD 6400 blowing hydr.fluid from scv

[valsup]

My dad owns a John Deere 6400 that blows hydraulic fluid from a scv that has nothing hooked to it. It happens about every 4 to 7 hours while running it. Everything will be fine and then all of a sudden it blows and doesn't stop until there is none left. The scv has been changed by John Deere twice and still not fixed. is any one else ever had this problem?
Thanks,
Virgil

 

[J_J]

Install plugs in the work ports.

or install QD's in the work ports.

or remove the wires from the solenoid if it is a solenoid valve..

How about a picture?

 

[Zebrafive]

Did the dealer change the valve or the quick coupler?
Very strange. I assume this a cable operated valve. Does the lever have a lock that locks the lever in neutral?
I guess I would install a male quick coupler tip with a plug installed in it.

 

[J_J]

That tractor is a closed center hyd system, and there is pressure at the valve at all times.

Do you mean that the work ports are not connected and are open?

Is the SCV valve, lever controlled or solenoid controlled?



If the lever vibrates to open position, then it will pass fluid through the OUT ports until there is no more fluid.

Again, is the valve, lever controlled, or cabled controlled.

If it is solenoid controlled, the springs in the solenoid might be weak, and can not hold the spool in the off position.

 

[Tx Jim]

I agree with J_J. I suggest to check pressure with a gauge. I suppose there might be a problem with the priority valve with the pressure relief valve(parts key #6).

 

[J_J]

What port is the fluid spewing from?

Hyd valves usually operate because of operator action, so is there something you are doing on purpose of accidentally?

Even if there is something faulty, a mechanical defect, you say it does this on a regular basis.

Most valves on a closed center valve do not have a relief valve.

Can you show a close up picture of that valve?

 

[valsup]

I'm working on the pics and answers to yalls questions. Im in Tx and my dad is in Mississippi which I am heading to shortly.
Thanks for all the good comments and I will get answers asap.
virgil