Big hydraulic fluid leak under right rear axle

[dgarvin57]

Just replaced the hydraulic fluid (Kubota UDT-2 at $100 for five gallons--ouch) and filters. The operator's manual said it took 4 gallons but fluid overflowed at 3.5 gallons. I later looked at the WSM and it said 3.5 gallons, which makes sense from my experience. I didn't unscrew the two drain plugs under the two axle housings (too lazy) and so maybe that was the extra fluid? But I did replace the filters. I might have made a booboo but I started the tractor and ran it a bit, thinking it would move fluid into the filters and lower the level. There was a small leak near the right rear axle before I changed the fluid.

Then worked the tractor for a couple hours and the leak got a lot worse until there was a swimming pool of fluid under my tractor. It was running down the inboard surface BH subframe from the right rear axle. Looked above and couldn't see any leaks from hoses, etc.

I suspect axle seal. Do you agree? Did I cause it or make it worse by overfilling? (BTW, I cannot read the fluid level on the dip stick. It always looked like it was too full. Very hard to make out actual level.) I've read that a plugged vent could cause this on some tractors. Where is the hydraulic vent on this tractor?

Finally, if it is the rear seal, I'll replace it. Wondering if I should also replace the bearings and would like any opinion or guidance from you kubota heros. Thanks.

 

[RCW]

What tractor are you working on? The B2920 in your profile?
You changed fluid without removing drain plugs, just pulled filter?
Guessing you’re greatly overfilled. I would drain it by removing the plugs into a clean container and start over. Re-use the fluid if possible.
At the very least drain enough to reach proper fluid level.
I honestly would not run it anymore as it is, to be on the safe side.
Many times they will not take all of they stated capacity.
Set your dipstick on a paper towel. You will see how much of the stick is wet.

 

[thebicman]

If you didn't remove the drain plugs then how would you expect to get all the fluid out. Especially any crud that is laying on the bottom. If your not going to do it correctly then why bother. You need to check the level and yes it's difficult to see but not impossible.

 

[dgarvin57]

Yes, this is the B2920HSD. I did remove the center drain plug (by the mid PTO) and drained many gallons. Just did not remove the two smaller drain plugs on the bottom of the axle housings.

Thanks for the reply RCW and thebicman, noted.

Now to fixing it. Any thoughts/encouragement on the diagnosis? Axle seal? Thanks.

 

[dgarvin57]

Also, Kubota recommends using Three Bond 12060 or equivalent for gasket sealer around the axle housing. I can't seem to find that exact product. I can find Three Bond, but they have many different products. Can anyone point me to the right stuff.

Also, any help in finding the hydraulic vent? Thanks again.

 

[RCW]

Oh, gotcha....so you likely got most but not all out.
Not familiar with B’s but often the vent looks like a question mark in the area under the seat somewhere.

 

[Russell King]

Yes you may have caused a seal problem by over filling it.

Get the level to the proper level and see if it changes anything.

I imagine you may think it is leaking just sitting (and it might be) but it may have leaked when running and is just dripping down now.

I think you should try to clean the outside of the tractor so you can see what is going on. If you can get to the seal easily it may have been pushed out of place. You may be able to get it back into place but you should probably replace it at that point.

The three bond products may be available at your dealer and there are also substitute products. Search through this forum for those discussions or just search the websites of similar adhesive manufacturers.

 

[whitetiger]

Three Bond 12060 or equivalent for gasket sealer
[/Q
Must be a miss print, it should read Three Bond 1260D. Permatex 82194 Ultra Grey Rigid High-Torque RTV is also a good choice.
Your vent should be to the left of the hydraulic oil fill plug.

 

[dgarvin57]

Thanks all. Great info. Russel King, unfortunately, the backhoe is installed on the tractor and with the backhoe subframe, it's not possible to even access the seal. I'll have to disconnect the backhoe by hand now (no hydraulics) and then remove the backhoe subframe. It was pretty well pouring out down the inside of the backhoe subframe after I hobbled into the shop.

whitetiger, thanks for the attachment. Really helpful. I have a download of the WSM but the pictures are really bad quality. I think I got ripped off on the download. Where did you get your good copy with color pictures? I don't mind paying the official price for it as long as it is a pdf with real color readable photos, like yours.

Yes, I now see the Three Bond 1260D, not 12060. My mistake.

I'll look for the hydraulic vent. I can see it now on the parts diagram on Messicks site. Thanks.

So what about changing the bearings while I'm in changing the seals? Is that recommended? Any special tools or gotcha's I should be aware of? Thanks again to all.

 

[dgarvin57]

Update. I see the vent right next to the fill hole. Not plugged. I've jacked the tractor up and removed the wheels and backhoe subframe and cleaned things up. I can see the axle seal coming out. So it definitely blew the seal. I'll proceed with replacing seals and bearings in both left and right rear axles. I can also see a bit of fluid leaking from the loader valve on the right side. Since I have to disconnect the lines coming in so I can detach the valve body (it's bolted to one of the axle bolts), I'll replace the o-rings just to be safe.

I called Messicks and they sold me a pdf of the actual WSM, which they emailed to me: About $68, or half the price of the print manual. Pictures are great. Many color photos.