Help with L3710 Leak

[tbk5]

I recently purchased a used L3710 HST to replace an L3010 that was totalled in tyransport when I moved. The 3710 had less than 800 hours it. It has a minor leak around the rear PTO area. There was a lot of load and caked dirt on the drawbar frame. I thought it might have been the PTO seal so I replaced the seal, slinger and o-ring when I did my 800 hour service. I don't think the HST filter was ever changed on this tractor. It was on tight but lost its battle with a saws all. Anyway, changing the PTO seals did not fix the leak. Now that everything is cleaned up, it looks like the oil is coming from around the area of the 3pt lower link (area of red circle in photo).

Does anyone know what I should be looking for? What seals are in this area? I can't tell if I should focus on the rear axle or the lift arm. The parts diagram show a seal for the rear axle but it is at the outer end of the housing, not near the leak. The lift arm diagram just shows o-rings. Does anyone have a suggestion?

 

[Russell King]

I recently purchased a used L3710 HST to replace an L3010 that was totalled in tyransport when I moved.

Whoa there cowboy!
That should like a story that has to be told, unless it is still too painful to discuss.

I have no idea about your leak but the o ring would be used for sealing oil in

 

[tbk5]

Whoa there cowboy!
That should like a story that has to be told, unless it is still too painful to discuss.

I have no idea about your leak but the o ring would be used for sealing oil in

i will tell the story in another thread. I have pics too. I am still angry. more than two years later.

 

[whitetiger]

Your leak may very well be your Hydraulic Oil Level Sight Gauge. If it is, drive the LH rear tire up on some blocks so the oil is away from the gauge, pop it out with a screwdriver, clean to hole with Brake Clean or rubbing alcohol. Put a light coat of RTV sealer around the rubber sleeve on the sight gauge and push it back in the hole. Let it cure for a while and drive off of the blocks.

If it is leaking from around the LH 3 point rock shaft seal, there is an o-ring seal under the lift arm. When you remove the lift arm from the rock shaft, mark the shaft and arm as they need to be timed. There is a mark on the shaft and one on the arm already but is hard to see at times. It is easier to mark them yourself.

It is not your axle shaft seal. There is a seal on the final drive drain plug, but I doubt that is your leak.

 

[tbk5]

Thank you. I think it's below the oil level sight but I'll start there. That seems easy enough to clean and reseal. I'll also start learning about lift arm surgery. Do the seat and fenders need to come off to change the o-ring on the LH lift arm? I may have to wait until after summer to tear it down if yes.

 

[tbk5]

From the parts diagram, it loks like the LH lift arm o-ring should be an easy replacement. Just one bolt holding the link control on. The o-ring is between 2 bushings. I see what you mean about adding a timing mark.

 

[tbk5]

Whitetiger-I think you are spot on with the oil level sight. I cleaned everything up yesterday with brake cleaner and a dry rag before I took the picture above. This morning, I could feel oil right below the site level. Nothing below the lift arm is wet until I pass the sight level. Obivously I never suspected that. I will pick up a new one before I take it off, just in case I munge the seal more than it may already be. Finally, something easy! Thank you again for the suggestions.

 

[tbk5]

A follow up.... I replaced the sight level and the leak is gone. I did not need any sealant. It was a nice tight fit. The old sight glass had sealant and the ring had some dings.

 

[Parkandeat]

Any tips with replacing sight glass. I am having same issue and thought I could seal around existing without removing. I wonder why from factory they use a sealant but the replacement just a pressure fit?

 

[tbk5]

I pointed the tractor downhill so that no fluid was visible in the sight glass. The old one popped out easily with a small pick. It looked like it had been out already as the edges mangled a bit. I had to scrape the old rtv sealant the previous owner had applied. (Carefully--did not want it to fall into the case. I kept the new sight glass in the fridge overnight to shrink the rubber seal a bit. It fit right it. I used a socket as big as the perimeter of the seal at tapped lightly with a rubber mallet to make sure it was seated. I let it sit for an hour to get to ambient temp just becasue. No more leak.

If I recall, the part is about $12. I just waited until I had a larger order and added it to avoid paying to ship one item (or a multi-hour round trip to a dealer.)

 

[Parkandeat]

I pointed the tractor downhill so that no fluid was visible in the sight glass. The old one popped out easily with a small pick. It looked like it had been out already as the edges mangled a bit. I had to scrape the old rtv sealant the previous owner had applied. (Carefully--did not want it to fall into the case. I kept the new sight glass in the fridge overnight to shrink the rubber seal a bit. It fit right it. I used a socket as big as the perimeter of the seal at tapped lightly with a rubber mallet to make sure it was seated. I let it sit for an hour to get to ambient temp just becasue. No more leak.

If I recall, the part is about $12. I just waited until I had a larger order and added it to avoid paying to ship one item (or a multi-hour round trip to a dealer.)

Very Helpful! Thank you, will work on it tomorrow

 

[tbk5]

Let us know how you make out

 

[tbk5]

Whoa there cowboy!
That should like a story that has to be told, unless it is still too painful to discuss.

I have no idea about your leak but the o ring would be used for sealing oil in

I finally was able to write about it. https://www.orangetractortalks.com/forums/threads/oops-lets-see-them.49464/post-472953

I am still cursing.....