Hydraulic leak at inlet port of NX joystick valve

[Threepoint]

My 2014 NX4510HST has developed a significant hydraulic leak at the inlet port of the joystick valve, where the fluid from the primary hydraulic pump enters the valve body.

See the red arrow in the two pics I've attached. One view is from the right side of the valve, angling upward; the other is from below.

I can get a big wrench on the fitting, and it is not at all loose at the point of the leak, unfortunately. I was hoping the fix might be that easy. :no: For that matter, I don't know if the fitting has NPT threads or uses a gasket at that joint. Nor do I know what is involved in removing and re-seating or replacing it, if that is indeed the problem. Anyone know if I'd have to drain most of the HST oil from the system first? I'm guessing yes, but hopefully not, as the fluid was just changed by my dealer recently during service.

Because access is so tight, I'm inclined to just bite the bullet and have the dealer pick the tractor up so my excellent tech can take care of this. I'll talk with them about this on Monday and send them the pics. But it's a 95-mile haul each way, so in the meantime I wanted to tap the wisdom here.


Side View - see red arrow


View from below - see red arrow

 

[countrybumpkin]

There is a O-ring on that fitting, just remove the line going to the fitting, and then loosen the nut on the 90 fitting, then the fitting should unscrew with little effort. You should be able to get a o-ring at any good auto parts store, it may be a bonded o-ring, will look like a metal flat washer with a o-ring made to it.

 

[Threepoint]

Thanks, Country. Couple of questions. Will I have to drain the HST oil first, or will the pump and the valve keep the fluid from draining beyond what's in the line?

Will the hose-end fitting that connects to the right angle fitting re-attach and seal once I'm done? Will it require dope? Really appreciate the help!

 

[747driver]

When putting the new o ring on don't tighten to tight, otherwise it will distort the seal causing it to leak.

You should only get fluid thats in the line. Just put a rag in the hole until you are ready to install new one. Should be a self sealing fitting on the hose end fitting.

 

[countrybumpkin]

When putting the new o ring on don't tighten to tight, otherwise it will distort the seal causing it to leak.

You should only get fluid thats in the line. Just put a rag in the hole until you are ready to install new one. Should be a self sealing fitting on the hose end fitting.

Pretty much this.

 

[Threepoint]

Thanks, Guys!

 

[LD1]

Cannot really add much other than if it is indeed an o-ring and not a bonded seal.....I would go to a hydraulic store and NOT an auto parts store.

ORB fittings arent standard dimension o-rings. They are a category by themselves in terms of nominal sizes and cross sections. n top of that, most auto parts stores only stock 70 durometer o-rings.....and ORB fittings are typically a 90.

Napa.....if you have one.....makes hydraulic hoses and has a good selection of fittings. (at least around here). so IF an autoparts store is where you go, that would be my choice

 

[countrybumpkin]

I did say GOOD auto parts store. Guess I should have elaborated a bit more and said one that deals in hydraulics services. Thanks for pointing that out to him.

 

[Threepoint]

Update: Matched the metric O-ring at a local NAPA store, and no more leak. A 60 cent fix. Only lost two or three ounces of hydraulic oil during disassembly, all from the hose. Thanks again for everyone's help.

I've attached a closeup of the right-angle ORB fitting for anyone else who may develop the problem. The fitting threads into the inlet port of the joystick valve just until snug. The captured nut is then tightened against the flat washer to sandwich the O-ring between the washer and the boss on the valve body.

I'm a little surprised that the O-ring failed, as the tractor is only four years old. It was a bit stiff, but I'm thinking it may also have been compressed too much when the fitting was initially installed.

 

[countrybumpkin]

Glad you got it fixed.