L4760 Hydraulic Leak

[shawnkey]

Hi, Folks. I'm new to the forum, and I appreciate the opportunity. In advance, thank you for your considerations.

I purchased a 2023 L4760 HSTC with 300 hours from my local dealer a few months ago. Prior to taking delivery, I bought a grapple and opted for dealer installation of the third-function valve. I provide this information as background, although it may not be relevant.

As I began to use the grapple, I noticed hydraulic oil on the pavement. Thinking the third-function valve was leaking, I tightened all the connections. The leak eluded me.

I narrowed the leak to a connection just above and behind the transmission fluid dipstick/fill cap. The photo below shows the general area with an inset photo of the L-shaped connection. In the inset, notice the gasket to the left of the large nut in middle. I believe the leak originates at or near this gasket. I confirmed by placing a piece of cardboard just below each L-connection (there are two), and the cardboard under the left L-connection had a couple teaspoons of oil on it after an hour's use of the tractor.

I would be appreciative of any advice regarding how to repair the leak. I wouldn't be upset if you also can educate me as to the proper nomenclature of the parts.

 

[TheOldHokie]

Hi, Folks. I'm new to the forum, and I appreciate the opportunity. In advance, thank you for your considerations.

I purchased a 2023 L4760 HSTC with 300 hours from my local dealer a few months ago. Prior to taking delivery, I bought a grapple and opted for dealer installation of the third-function valve. I provide this information as background, although it may not be relevant.

As I began to use the grapple, I noticed hydraulic oil on the pavement. Thinking the third-function valve was leaking, I tightened all the connections. The leak eluded me.

I narrowed the leak to a connection just above and behind the transmission fluid dipstick/fill cap. The photo below shows the general area with an inset photo of the L-shaped connection. In the inset, notice the gasket to the left of the large nut in middle. I believe the leak originates at or near this gasket. I confirmed by placing a piece of cardboard just below each L-connection (there are two), and the cardboard under the left L-connection had a couple teaspoons of oil on it after an hour's use of the tractor.

I would be appreciative of any advice regarding how to repair the leak. I wouldn't be upset if you also can educate me as to the proper nomenclature of the parts.

The gray painted portion that goes into the casting looks like some sort of DIN tube fitting. Is it leaking at the joint with the gray hex nut and the silver elbow?

Dan

PS> great picture work!!

 

[Russell King]

I noticed that this “rubber” part seems to have a split in it. That may be there intentionally so you might look at the other side to see if there is one there also.

I assume that is sealing the tube into the case and that is where it is leaking. You may be able to see it leaking or set up a camera to monitor that when you are using the tractor?

 

[North Idaho Wolfman]

HAHAHA @TheOldHokie @Russell King
That's a pipe clamp.

 

[North Idaho Wolfman]

Hi, Folks. I'm new to the forum, and I appreciate the opportunity. In advance, thank you for your considerations.

I purchased a 2023 L4760 HSTC with 300 hours from my local dealer a few months ago. Prior to taking delivery, I bought a grapple and opted for dealer installation of the third-function valve. I provide this information as background, although it may not be relevant.

As I began to use the grapple, I noticed hydraulic oil on the pavement. Thinking the third-function valve was leaking, I tightened all the connections. The leak eluded me.

I narrowed the leak to a connection just above and behind the transmission fluid dipstick/fill cap. The photo below shows the general area with an inset photo of the L-shaped connection. In the inset, notice the gasket to the left of the large nut in middle. I believe the leak originates at or near this gasket. I confirmed by placing a piece of cardboard just below each L-connection (there are two), and the cardboard under the left L-connection had a couple teaspoons of oil on it after an hour's use of the tractor.

I would be appreciative of any advice regarding how to repair the leak. I wouldn't be upset if you also can educate me as to the proper nomenclature of the parts.

The rubber part with the split is just a clamp.
Spray some brake parts cleaner on everything, then restart to look for leaks.
It more then likely will be a fitting that is not tight.

 

[TheOldHokie]

HAHAHA @TheOldHokie @Russell King
That's a pipe clamp.

View attachment 167821

Whoops.

But thats still a tube fitting (probably DIN) and the OP has not answered my question. If thats the location of the leak common sense would say "snug it up".

Dan

 

[Russell King]

HAHAHA @TheOldHokie @Russell King
That's a pipe clamp.

View attachment 167821

Well that explains why I couldn’t locate any connections like that in the illustrated parts lists! I saw the diagram you posted but didn’t recognize it as that pipe clamp!

 

[shawnkey]

The gray painted portion that goes into the casting looks like some sort of DIN tube fitting. Is it leaking at the joint with the gray hex nut and the silver elbow?

Dan

PS> great picture work!!

Dan,

Thanks for your response and compliment regarding the photos.

I inspected the area again before responding. Each side mirrors the other; see the photo below. From the casting, I find first a rubberized seal, the DIN tube fitting you reference, the hex nut, and then the elbow. I cannot accurately answer whether the leak is at the joint.

I noticed that this “rubber” part seems to have a split in it. That may be there intentionally so you might look at the other side to see if there is one there also.

I assume that is sealing the tube into the case and that is where it is leaking. You may be able to see it leaking or set up a camera to monitor that when you are using the tractor?

View attachment 167819

The rubber part with the split is just a clamp.
Spray some brake parts cleaner on everything, then restart to look for leaks.
It more then likely will be a fitting that is not tight.

 

[shawnkey]

@TheOldHokie asked where precisely it was leaking. I prepared another photo (below). Before I posted, I wanted to go test to see if I could more particularly answer the question. I inadvertently posted a partial response.

Thanks, @North Idaho Wolfman and @Russell King, for pointing me in a direction. I will clean the area and see if I can determine if the leak springs from the fitting. I'll report back after I make the determination.

 

[shawnkey]

I removed the 20 mm nut that held the pipe clamp (see below). In turn, I was able to easily remove the rubber bushing (see below). @Russell King correctly noted that the bushing is split by design. I then unscrewed the connection at the top side of the fitting (see below) to give me some flexibility to tighten the end of the fitting joined with the large nut. This was not easy. There's not a lot of space to maneuver or gain any leverage. As I turned the nut to the right, I used a pair of vice grips to hold the fitting in place, being careful not to damage any of the threads. Ultimately, @North Idaho Wolfman identified the issue as a leaking fitting. I cleaned the area, cut a clean piece of cardboard to fit under the fitting, and used the tractor and hydraulics for better than half an hour. So far, there's no detectable leak.

Thanks for all your contributions. That pipe clamp and split rubber bushing gave me cause for pause at first. Ultimately, the fix was much more straight forward and clearcut that I anticipated.