Leaking Hydraulic Coupler

[Grit]

I noticed a drop of oil coming out the front of one of the hydraulic couplers. It is the bigger one on the bottom. When I first got the machine, I had noticed build up around the end of the hydraulic arm that attaches to the bucket. I assumed the seal around it was leaking, but after discovering the hydro oil leaking out of the coupler, I figure it is dripping down onto the hose (shown in pic) and ending up around the front face of the hydraulic arm (also shown in pic). You'll have to forgive me for not know what these parts are called. I am still learning. I have provided pics for reference.

My question is, can I replace the coupler without much trouble? And if so, how do I depressurize the system in order to get this done? I don't want to lose tons of fluid trying to do this. It looks like there's just a lock nut on the back side and it just unscrews?

Thanks for any and all help.

Hopefully these pics will show up. I am still learning how to do that as well.

Ha, it worked!

 

[durallymax]

Leaking auxillary couplers are common when operators don't clean them before inserting hoses or beat them with a hammer because they didn't release the pressure.

If the machine has been sitting off there wont be much pressure on it, you can wiggle the aux control back and forth to relieve some of it.

The "lock" nut is actually the Jam nut for the bulkhead style fitting that NH uses. First loosen the hard steel line and unthread completely from coupler. It will be a JIC 37* flare so it should turn nice by hand but make sure you do not tighten it too hard when you reinstall it and do not put anything on the threads. Either of these practices will damage the flare and it will leak.

Then remove the jam nut and the coupler will come out of its mounting hole, repeat for installation.

Here's a link to the coupler you should need . Remove your old on first, if you see an o-ring in the face versus a flare then you need an ORFS fitting and not a JIC.

http://www.zorotools.com/g/00130244/k-G4701855?utm_source=google_shopping&utm_medium=cpc&utm_campaign=Google_Shopping_Feed&kw={keyword**&gclid=CIXh0YKQk70CFe87MgodWVYAmQ

 

[Grit]

Man, I don't know what I would do without your help. You are always coming to the rescue. By the time I get this machine back in tip top shape and all fluids and filters changed out, I will owe you big time. Your help is greatly appreciated!

Question: If so happen I did need to release the pressure on the hydro system, how would I do that?

You explained the uninstall and install very well. Thanks for that.

The link you provided seems to not be working. I tried a copy and paste and didn't get anything either.

Thanks for the help!

 

[durallymax]

You can always just crack the line and it will let off the excess pressure. Keep hands away and wear glasses obviously.

Copy and paste worked for me, just search for Parker PN: FEM-501-10BMF-NL thats what you are really after, I have no specific site you should but it from. Your NH dealer may have one too.

 

[Grit]

Ok, thanks. Crack the line? You mean pull back on the coupler as if you were going to hook in an implement? Or do you mean loosening the steel line on the coupler? Sorry, just trying to understand what you meant by cracking the line.

I was thinking maybe that red button under the seat released pressure on the system as well? I don't know.

 

[CRAFT]

Ok, thanks. Crack the line? You mean pull back on the coupler as if you were going to hook in an implement? Or do you mean loosening the steel line on the coupler? Sorry, just trying to understand what you meant by cracking the line.

I was thinking maybe that red button under the seat released pressure on the system as well? I don't know.

Grit: the terminology "crack the line" refers to many things in the big world around machinery ……. cracking the line means like crack the retaining nut or what ever a little loose SLOWLY to relieve the pressure or if it were an under pressure injector line you would crack it loose to bleed air out …….. ALL Lines that are under pressure can be very dangerous if not dealt with in a diligent manner …… these types of lines under extreme pressure can blow a hole right thru your hand or blow your finger off ! …. in this case maybe not BUT you should be more aware of the repercussions of what COULD HAPPEN IF ???

Maybe before you start digging too deep in some of these things start checking out some safety videos on you-tube or i'm sure there are WorkSafe vids at your regional depts …….. Just a thought !

 

[durallymax]

http://www.fluidpowersafety.com/

 

[KSSS]

That machine should be just like the CASE machine in the sense that you should not have to "crack the line". Sit in the seat, turn the key to on but don't start it, release the park brake, and actuate the aux. hyd button back and forth. That will drop the pressure without having to turn a wrench and make a mess.

Being it its a NH you may have to buckle yourself in and then release the park brake.

 

[durallymax]

That machine should be just like the CASE machine in the sense that you should not have to "crack the line". Sit in the seat, turn the key to on but don't start it, release the park brake, and actuate the aux. hyd button back and forth. That will drop the pressure without having to turn a wrench and make a mess.

Being it its a NH you may have to buckle yourself in and then release the park brake.

This would be the correct method. Thanks for explaining it.

 

[Grit]

KSSS, thanks, that is what I was looking for. So the switch is on the left pilot control handle? What exactly is that control for? I have read about it, but it doesn't make any sense to me.

Thanks for the help, guys, and thanks for that link, durally.

 

[Grit]

Well, I don't have that function on my pilot control handle. So I don't know where it would be.

 

[Grit]

Oh, just a little additional information on that leak. I cleaned up down below where it was leaking all over the smaller lower hose and fitting going into the cylinder. I didn't want it leaking on it again until I could get it fix, so I put a small plastic bag over the end; One, to catch any more leaks until it is fixed and, two, because I wanted to see if it was going to leak after wiping it clean. It hasn't leaked since I covered it. That tells me it is probably only leaking under pressure or when the machine is running. Would it still be a good idea to replace it?

 

[CRAFT]

Oh, just a little additional information on that leak. I cleaned up down below where it was leaking all over the smaller lower hose and fitting going into the cylinder. I didn't want it leaking on it again until I could get it fix, so I put a small plastic bag over the end; One, to catch any more leaks until it is fixed and, two, because I wanted to see if it was going to leak after wiping it clean. It hasn't leaked since I covered it. That tells me it is probably only leaking under pressure or when the machine is running. Would it still be a good idea to replace it?

Without going back in time (past postings, or when you inquired about the purchase thread) this machine has long stroking joy (L&R) levers to steer and pedals on floor for bucket and boom function ??? right??? (it's a totally mechanical system with push rods to actuate the spools which are located between your legs behind a removable floor panel, lift the seat and lock in up position first if you need to look at how it works) ….. if so the aux lines are actuated by the tilting of the "Right side" right handle, by twisting inward & outward, there will be a locking pin on the outside of the lever (which turns out 90* pull down to unlock) to prevent movement when you are Not using aux hyd's ……

Let us know ???

 

[Grit]

No, it is full pilot controls. I guess that's what it is called. There is a right foot lever that control throttle as well.

Left pilot controls drive functions. Right controls boom a tilt functions for bucket or aux.

 

[CRAFT]

No, it is full pilot controls. I guess that's what it is called. There is a right foot lever that control throttle as well.

Left pilot controls drive functions. Right controls boom a tilt functions for bucket or aux.

K ….. Sorry can't help you ….. not familiar with your NH functions and it would be WAY different than my Bcat ……… Good-Luck !

PS ….. the way the cyl end looked to me is the seal on the cyl rod seal is weeping and NOT coming from above, unless somebody wiped the residual oil off of the top of the Barrel …….as far as the flat-face couplers goes sometimes there will be some piece of crap stuck in there and IF you had the male end to stick in there and cycle it a few times it will re-seal by releasing the foreign matter, that is also an easy way (and really safe way) to release the pressure from the line when the machine is not running push a coupler into it with a short hose on it …………… BUT, Please do read up on Safety of what was mentioned before …. it's not a matter of if you will get hurt it's WHEN if you are not aware of the dangers …. you could also Loose an eye !

 

[Grit]

Thanks, CRAFT. That's ok, I'm sure someone will come along that is familiar with it. Hopefully.

I too first thought that it was the seal and had mentioned it in an earlier post. But when I saw the coupler leaking, I just figured that was the cause. I realize that it would have to run up the cylinder to have it covered like that, but then I thought maybe what was already down there worked its way up there when the boom was at full reach? I don't know the angles, so don't know if that is possible. If the previous owner did a lot of loading, that might explain it. But, the seal could very well be leaking too, I'll just have to keep an eye on it. I have cleaned everything up so if anything else is leaking, it will show up eventually.

Thanks for your time and trying to help!

 

[KSSS]

My machine that is similar to yours is a servo machine and not pilot. However I think it clears the same way regardless of whether it is servo or pilot (but I cant be certain of that). Whatever the switch is that actuates the main hydraulics is the switch that will clear the lines. Many times especially with grapple buckets, the hyd lines will be taunt, and if you remove the lines from the machine when they are full like that you will never get them back on without cracking the line. Before removing the lines from the machine make sure you remove the pressure. If you do that you will never have to crack a line. If you don't know which switch activates the main hyd. look in the book or post a picture and I could likely tell you which it is.

also if you hook up to an attachment and the line pressure was not relieved prior to hose removal, if you can get one line on the machine and do the sequence as I outlined it will equalize the pressure and allow you to get the other line on.

 

[tmc_31]

Hey Grit,

I didn't realize that you had pilot controls on your machine. Mine has the old standard mechanically linked controls. That said, the way I relieve the pressure on my hydraulic circuit is to turn the key to ACC then activate the aux control back and forth. It may work the same on yours, worth a try.

Tim

 

[Grit]

Thanks, Tim. I have been looking for a solution to this since last night, but have not had any luck thus far. I have looked in my operators manual from front to back cover several times and have not seen anything that would answer my question. The only thing it says under the section SAFETY is, "Before disconnecting lines or fittings, be sure to release all pressure by operating the tractor control valves". That is all the book says. That just about tells me nothing, lol. It might mean something to you guys, but not me.

The only AUX I see in the cab is on the control pad, and it says aux override. It only has one button for it. There are others functions on the same pad as well. Road Lights, Work Lights, Aux Override and Park. They are also used for AIC operator setup and menu functions.

 

[KSSS]

It will likely not say aux. hyd. It is a switch that is on the control handle. If you can post a photo of both control handles and I will tell you which it is. You can also hook up a hyd attachment and use the switches on the control handle to make the attachment function. That will be the switch that you use to clear the lines. Somewhere in the manual is a diagram that shows all switches in the cab and on the control handles. There is will a corresponding section using numbers usually that will tell you what the numbered function is. I am guessing it will be a roller type switch that CNH used on the Pilot machines, but it depends on what options your machine has.