Hydraulic Coupler Leaking at Case Drain when Attaching

[RockyHillRanch]

2012 Kubota SVL90 Standard Flow,

When I am attaching the hydraulics for the grapple to the machine, an excessive amount of oil flows out of the case drain port while i am connecting. Once the hose is fully seated, it doesn't leak anymore.

Is this a pressure relief mechanism? I tried manually reliving the pressure, but no change. Or is this pointing towards worn out o-rings? I lean towards a bad seal, as it is not a little amount of oil that comes out.

Ideas? Thanks

 

[Cliffy]

Case drains are usually connected directly to tank with no back pressure.
But yes, id say the couplings are worn out.
Dirt kills the internal seals. Dont wipe the face, spray with brake clean to remove dirt before connecting.

 

[RockyHillRanch]

No drain hose on the grapple. After a bit of looking, i think this is called a service port, rather than a case drain. Is that correct? This is a standard flow SVL90

Brake clean is a good idea. The leaking comes out of the third port that i never use though. Probably will have to find a seal kit for it. But again, its so much oil that i don't think only seals will fix it. It almost seems like a PRV that is failing.

Edit: Well, it is definitely a drain. So i assume the check valve is bad. If anyone knows the thread size on the coupling block that would be great to know. Other I will drive to the ranch and check this weekend.

 

[Tones]

If the case drain is never used then remove the coupler and replace it with a plug. It'll never leak again in your life time with this machine.

 

[RockyHillRanch]

If the case drain is never used then remove the coupler and replace it with a plug. It'll never leak again in your life time with this machine.

This is likely what i'll do for the time being. I should have some plugs around.