JD650 Rockshaft control valve leaking

   / JD650 Rockshaft control valve leaking #1  

BCinMI650

Bronze Member
Joined
Feb 2, 2019
Messages
70
Location
SE Michigan
Tractor
John Deere 650
Hello experts!

I’ve got a fresh problem and thought I would come back to this honey hole of knowledge.

The rockshaft control valve on my John Deere 650 is leaking at the feedback rod. This had happened before just before my hydraulic pump twisted its shaft off. So I repaired the hydraulic pump, ordered a new rockshaft control valve (the original didn’t seem to be operating correctly, as it really only gave me 3 positions to choose from, all the way up, all the way down and somewhere vaguely in the middle) and buttoned it all back up. It seemed to be fine for a while, but while clearing some land at the edge of the swamp tonight I noticed my rockshaft housing was soaked in hydraulic oil and the seal that the feedback rod passes through was pushed out again (same symptoms from when the hydraulic pump imploded before). There is also a faint sound that sounds like a relief valve opening or strained but is not nearly as loud as when it actually opens from me trying to lift something I can’t with my front loader. Any ideas on what could be causing this? Am I building up pressure in the rockshaft control valve and that’s the path of least resistance out?

Any ideas would be greatly appreciated.

Thanks!
BC
 
   / JD650 Rockshaft control valve leaking #2  
Does the relief open slightly when you pull the sector handle all the way back or just in general lifting the 3 pt?
 
   / JD650 Rockshaft control valve leaking
  • Thread Starter
#3  
Anytime it is even the slightest bit lifted with weight on it but not nearly like it used to before I replaced the control valve and adjusted the handle (it used to truly scream, as the previous owner had been trying to maximize how high he could lift the 3 pt).
 
   / JD650 Rockshaft control valve leaking
  • Thread Starter
#4  
I cracked in the inlet to the rockshaft control valve today and that didnt seem to make a difference in the straining noise. I then rotated the rate of drop level back and forth, and I THOUGHT the pitch of the straining noise changed as I did it. System is an open center hydrualic system if that helps.
 
 
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