Kubota L3940 All the Sudden Won't Move and Hydraulics Won't Work

[webmonk]

I was mowing the back side of our pond dam. I back down and drive back up. I have done this many times before. After a few times today I was driving back up and all the sudden my forward movement stopped. I put my foot on the brake and tried a few times to drive up, making sure that it was in gear, but every time I let off the brake I would start rolling backwards. I tried the hydraulics (loader and PTO mower) and neither would raise up. I turned it off and started it again hoping that would reset something, but it didn't. After several attempts in different gears and settings (in case I bumped something) I gave up.

Does anyone have any idea of the likely cause and solution?

 

[Rebeldad1]

basic stuff to start. check hydraulic fluid incase something like a hose or fitting broke. check fan belts incase the pump is driven by belts.

 

[ptsg]

It sure looks like you lost all of your fluid. Definitely check your fluid, then take a look under the tractor. Pretty sure a stick or something pierced an hole of the hydraulic filter or pulled another line apart.

If it's HST, that would explaining it rolling when you release the brake as there is no fluid on the pump nor motor, it will just free spin. A very dangerous aspect of the HST that's is often overlooked. Specially if working on the steep hills.

 

[Rebeldad1]

OP... where are you at with this?

 

[webmonk]

I noticed a large area (somewhere else) where some fluid had leaked where I had it parked. It wasn't a drip because it was a wide area, maybe like 3' x 3'. That was a bit disturbing.

At the advice of someone I tried adding more hydraulic fluid. I have no way of knowing what level it's at because it is still stuck on the hill and the dip stick and fill hole are both on the downhill side. I put in maybe 2-3 quarts. I was still unable to get it to move after adding more, but I was able to move the implements (although reluctantly).

I tried to tow it up about 15' to level ground so I could better diagnose things, but was unable to with my SUV. I have someone else with a tractor coming today to tow it up. Hopefully I'll know more by tonight.

 

[ptsg]

2 to 3 quarts is nothing on a tractor that lost most of the fluid, although, being on the hill, I'm sure there is still some in it. Accordingly to TractorData, that tractor takes a total of 11.4 gallons of fluid.

 

[sea2summit]

I noticed a large area (somewhere else) where some fluid had leaked where I had it parked. It wasn't a drip because it was a wide area, maybe like 3' x 3'. That was a bit disturbing.

At the advice of someone I tried adding more hydraulic fluid. I have no way of knowing what level it's at because it is still stuck on the hill and the dip stick and fill hole are both on the downhill side. I put in maybe 2-3 quarts. I was still unable to get it to move after adding more, but I was able to move the implements (although reluctantly).

I tried to tow it up about 15' to level ground so I could better diagnose things, but was unable to with my SUV. I have someone else with a tractor coming today to tow it up. Hopefully I'll know more by tonight.

Do you see any in the sightglass or dipstick? If not I'd add until you do, if it dumped all the fluid I'm surprised it could even get pressure with only 2-3 quarts. Did you already check the plugs? Any other obvious signs of leaks?

 

[Leejohn]

After you get it on level ground or shop, on the right side at the firewall see if there is a short rubber hose on the pump inlet line, check for cracks or hole. Then check the little button under tractor at the bell housing and see if you have oil coming out. Then I would check the screen on the inlet in the trans and change filters.

 

[jonsstihl]

The grand L 40 series has no screen on the inlet pipe. the suction filter is the screen but definitely check the split pin plug on the bottom of the trans and the rubber coupling elbow on the inlet pipe to the hydraulic pump like leejohn said.

 

[ning]

I noticed a large area (somewhere else) where some fluid had leaked where I had it parked. It wasn't a drip because it was a wide area, maybe like 3' x 3'. That was a bit disturbing.

At the advice of someone I tried adding more hydraulic fluid. I have no way of knowing what level it's at because it is still stuck on the hill and the dip stick and fill hole are both on the downhill side. I put in maybe 2-3 quarts. I was still unable to get it to move after adding more, but I was able to move the implements (although reluctantly).

I tried to tow it up about 15' to level ground so I could better diagnose things, but was unable to with my SUV. I have someone else with a tractor coming today to tow it up. Hopefully I'll know more by tonight.

Improvement with 2-3 quarts is promising.
I'd add gallons. Worst case is that it overflows out the fill neck; best case is it moves and then overflows.
Just how steep was that bank you're parked on?

 

[crazyal]

Get it up to level ground and get yourself at least 10 gallons of hydro oil. Follow the directions in the manual to check the level and fill it. After the first gallon stop and look for any leaks. If none are seen add a few more gallons and look again. Also start checking the level with the dip stick. If no leaks are found then start the tractor up once the level looks good (or you have all 10 gallons in there). Look for leaks with it running. If none are found start moving the loader and 3pt hitch while looking for leaks. Once a leak is found shut off the engine and repair it. I might try to drive it back to the shop but only if the leak is very small. If the level drops far enough so the tractor will not move you are risking expensive damage to your HST system.

 

[webmonk]

Okay. Neighbor pulled it up to level ground. I tried to start it but it wouldn't start. I checked the hydraulic oil level and it didn't even register on the dip stick. I can buy more and top it off, but I looked under the tractor to see what might have caused the large oil residue where I had it parked in the grass the day before. Oil was dripping from the split pin. See the URL below to view the precise location (green circle). Let me know if I'm incorrectly identifying this.

https://drive.google.com/uc?export=view&id=18lRynyxXECKrPLpYGk3cz9z6Zj7EkWip

After a bit the dripping slowed to nearly nothing. I've seen dripping from here a lot, sometimes more and sometimes less. I don't know the rhyme or reason as to what causes it to leak more.

I've read the horror stories about this possibly signifying a seal that will cost a significant amount to have replaced. Before I head down that undesirable road, are there other possible causes that I could easily check to make sure it isn't something simple?

 

[nybirdman]

Going through the same right now on my L4240,lucky I saw it leaking from the pin before any damage.At the dealers right now.
No easy or cheap fix,have to split the tractor$.

 

[Midniteoyl]

Okay. Neighbor pulled it up to level ground. I tried to start it but it wouldn't start. I checked the hydraulic oil level and it didn't even register on the dip stick. I can buy more and top it off, but I looked under the tractor to see what might have caused the large oil residue where I had it parked in the grass the day before. Oil was dripping from the split pin. See the URL below to view the precise location (green circle). Let me know if I'm incorrectly identifying this.

https://drive.google.com/uc?export=view&id=18lRynyxXECKrPLpYGk3cz9z6Zj7EkWip

After a bit the dripping slowed to nearly nothing. I've seen dripping from here a lot, sometimes more and sometimes less. I don't know the rhyme or reason as to what causes it to leak more.

I've read the horror stories about this possibly signifying a seal that will cost a significant amount to have replaced. Before I head down that undesirable road, are there other possible causes that I could easily check to make sure it isn't something simple?

Forbidden access to link. You need to share it.

 

[webmonk]

Forbidden access to link. You need to share it.

Sorry. Fixed. You can see it now

Going through the same right now on my L4240,lucky I saw it leaking from the pin before any damage.At the dealers right now.
No easy or cheap fix,have to split the tractor$.

 

[buckeyefarmer]

Link didn’t work for me after you said it was fixed.
I have L3940 so I’m paying attention.

 

[ning]

I managed to get it (app - long press on link - drive open) so:

 

[5030]

That hex bolt with the pin accesses the bellhousing and it it's leaking from there and it's low on tranny oil, a split is in order as your input seal has failed.

 

[Leejohn]

Going through the same right now on my L4240,lucky I saw it leaking from the pin before any damage.At the dealers right now.
No easy or cheap fix,have to split the tractor$.

Make sure they replace the 4wd shaft seal while they are in there and the sleeve that it rides on.

 

[CoyPatton]

I managed to get it (app - long press on link - drive open) so:View attachment 701120

The pin in that nut is to keep debris and such out of the weep hole in the nut. If you found a 3’x3’ oil spot in grass, you have a significant leak.
Splitting a tractor apart is a fairly serious labor endeavor, if you do not have a good means to support both parts of the tractor during separation and while apart and when reassembled, have it done. Both parts are heavy even on small subcompacts. The bigger the tractor the heavier the parts.
Due to the labor involved, relatively inexpensive seals, will result in an costly repair.
However the expense of constant filling of hydro fluid will offset the expense quickly if you do not do the repair. Not to mention the potential damage to other parts of the hydro system.