Grand L4740 hydraulic fluid leak. Ideas?

[lynrob]

I have a 2008 Grand L4740 with just over 600 hours. Recently I've noticed hydraulic fluid dripping from the toggle drain at the bottom of the clutch housing when put my tractor away after working it hard. It's not a lot of volume but a pretty steady drip for a while then it stops. I've checked the level and if anything it seems to be a little above the mark. I'm wondering if it is slightly overfilled and leaks out when the oil gets thoroughly warmed up and expands. I haven't noticed the leak when using the tractor for small jobs only when I use it for several hours at a time.

Do any of you know how hydraulic fluid might get into the clutch housing? I've never split this tractor and don't really know what the possible paths for a leak are. Other than the leaks everything seem to work fine.. I haven't noticed any issues at all.

Thanks!

 

[dstig1]

You SURE it's hydraulic fluid and not water? If we are talking about the same thing, it is meant to remove water/condensation....

 

[David_Kb7uns]

You did not say what type of transmission you have, FST, GST or HST. if it is a HST then from looking at the L3130-L5030 service book (think it should be similar for the 40 series) there is a HST charge pump on the input shaft before it goes into the HST pump/motor section and then into the gear section, whatever it is the sources of hydraulic fluid are few and need to be looked at.

Where are you at? out here by Foster Lake

David Kb7uns

 

[Leejohn]

It's the input shaft seal. I had mine leak and fixed under warranty, that didn't last long. I split the tractor and found the housing wasn't tighten down right also the seal seemed to fit loose. I got a new seal and housing, the seal I got was a different color and seem to fit better but had the same part #. So after a new seal, gasket and housing has been fine for about 2 or 3 years now. Make sure you tighten the housing nice and even. The housing should of had one more place for a bolt and you well see why when you get there.

 

[lynrob]

You SURE it's hydraulic fluid and not water? If we are talking about the same thing, it is meant to remove water/condensation....

yeah,unfortunately it's hydraulic fluid, but you are right normally I wouldn't expect anything but water out of that fitting.

 

[lynrob]

You did not say what type of transmission you have, FST, GST or HST. if it is a HST then from looking at the L3130-L5030 service book (think it should be similar for the 40 series) there is a HST charge pump on the input shaft before it goes into the HST pump/motor section and then into the gear section, whatever it is the sources of hydraulic fluid are few and need to be looked at. Where are you at? out here by Foster Lake David Kb7uns

Sorry, I should have said, it's an HST model.
I'm south of Corvallis near the airport.

 

[lynrob]

It's the input shaft seal. I had mine leak and fixed under warranty, that didn't last long. I split the tractor and found the housing wasn't tighten down right also the seal seemed to fit loose. I got a new seal and housing, the seal I got was a different color and seem to fit better but had the same part #. So after a new seal, gasket and housing has been fine for about 2 or 3 years now. Make sure you tighten the housing nice and even. The housing should of had one more place for a bolt and you well see why when you get there.

You have confirmed my worst fears... How bad is it to split this tractor. I'm fairly handy but I've never split one.. Should I attempt it or take it to a dealer?

 

[RedNeckGeek]

I had the same problem with my L3240 when I got it, used. The tractor was long out of warranty, and it would have been several thousand dollars for the repair at the dealer. I was able to talk to the mechanic there, who walked me through the repair and showed me the special frame/fixture they use to keep the two halves of the tractor lined up while they are apart. He was quick to point out that the same thing could be achieved by using a rolling floor jack to support the back of the front half and just rolling it forward until enough space is created to get in there and replace the seal. If I recall correctly, there is a paper gasket between the front and back half castings, and the seal on the transmission itself. All were special order parts at my dealership (pretty much any Kubota part is special order there), so I also ordered one of anything else I thought could be leaking so I'd have it on hand when I got everything apart. Most of the work came from just getting all the parts above the actual tractor frame off, like the deck and such. All that was pretty clearly spelled out in the Kubota shop manual (mine came from kellerkubota.com). I'm not a professional mechanic, but I do have a willingness to read and follow directions, a lot of hand and power tools, and I'm retired so I have more time than money. I used a come a long hanging from an eye bolt in the ceiling of the garage to pull the deck. It wasn't heavy but it was awkward, and more than I could handle by myself. If you have a cab on your tractor that could be an issue. I didn't need any special tools and I only ran into one problem. The Kubota manual doesn't mention it, but there's a steel hydraulic line that runs through a hole in the side of the cases, and that line needs to come off before you try to split the tractor. If you don't know that, you can still split it with a porta-power, but then you'll end up replacing that line. DAMHIKT. That may be the case for your tractor, or it may not, but just keep an eye out if the two halves seem stuck after you think you have all the bolts out.

If this turns out to be a known issue with your tractor (check the forum here) you could ask the dealer for "good will" toward some of the cost of repair. I used that strategy when the FEL mounts broke repeatedly on my tractor after finding that newer versions of the same mounts had been redesigned. It was like pulling teeth, but if you are firm but polite, you might save a lot of money.

However it turns out, good luck!

 

[TripleR]

Same thing happened to my L5740 at 150 hours and it was replaced under warranty. The WSM calls for removing the cab, but the mechanics were able to replace it without doing that.

 

[lynrob]

Thanks, Scot! I think I'll stop by the dealer and find out if they are willing to work with me. If not, I may embark on a new adventure! Thanks for the info!