I have a JD331G. I was mulching and somehow the top Hydraulic line got caught in the mulcher and rippled off the machine. It also damaged the quick disconnect on machine. I replaced everything all with new parts from John Deere. Now it seems when using my grapple that it leaks closed as soon as you release the switch. Less then 3 hrs on new grapple and it wont bleed down when disconnected from machine. Looking for some insight. ‘Thanks Chuck
Machine serial number? With nothing attached to your quick couplers, disconnect the small line from the rearward side of the left boom arm. Cap the hose leaving the tube from the boom open. Have someone operate the auxiliaries over relief, first in one direction, then the other over. Does any oil come out of the small tube?
Fixed it. Had a blown Oring on backside of quick coupler on machine side. Thanks Chuck
So glad I found this....been having the same problem. Was thinking something was wrong with valve but this makes so much more sense.
My coupler had some nicks in it so I just replaced it. Was only $100, so will get a new flat O‘Ring and I’ll have a spare.
I’m having the same problem can you be a little bit more descriptive or do you have any photos you can share? My grapple on my 331 when opened it leaks closed and when I’m trying to carry a load, it has no pressure and will let the load fall out. I hope the grapple to a bobcat and it worked great. I’m just stumped on what it could be on the machine side please help
That bottom groove where the O ring missing. Sorry for delay I was traveling
This thread was very helpful. I had the same problem with hydraulic pressure bleeding off when using a grapple or tree puller. When clamping down, it would just release. This O ring on the male quick coupler was shot. Actually totally gone. My machine was still under warranty that covered the hydraulic system as well. JD provide a new coupler that I simply screwed back in place of the hold one. The real problem for in the future is that JD does not just sell the $.50 o-ring. YOu have to buy the $125.00 coupler. If anyone knows the size of the O-ring that will replace this old one I would appreciate knowing that. AS I said my oring was completely gone so I can't match it up. Also, JD requires the old one to be turned in as part of the warranty coverage.