Oil leak??

[woodchuck2]

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I know my mini-ex is tired iron with over 6k hours but it just started leaking hyd. oil from the swing bearng area. I just found the grease fitting fo it about 3 weeks ago so i greased it and now the lump is starting to leak oil. I dont have any kind of service manual nor can i find one. A buddy of mine has an 08 Kuboto mini and he said he is suppose to grease the swing bearings every 200 hours, his manual states to grease it with 28-30 pumps for every 90deg. Thats alot of grease IMO!!! Now, my question is have any of you fella's had any kind of a leak like this and did greasing the crap out of it slow the leak or even stop it. I talked to a couple equipment mechanics in the past and they say if the swing bearings start leaking then get rid of the machine. Believe me, i would love to trade it in on a new Kubota but my finances wont allow at this time.
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[finaldrive]

If you are leaking hydraulic oil, it may not be that bad.
The only place for hydraulic oil to be introduced into the swing area is from the swing motor.
More than likely your swing motor shaft seal is leaking into the swing gearbox. The hyrdraulic oil will fill the gearbox and blow the swing gearbox shaft seal.
The hydraulic oil will then do the same to the grease bath for the swing bearing. It will fill the grease bath and leak out the seal for the swing bearing.
When you pump grease into the bearing, the hydraulic oil has to go somewhere and it goes out the swing bearing.

Pull the entire swing motor assembly with gearbox. Reseal the motor and gearbox, possibly install a new seal on the swing bearing and try it out.
Good luck.

 

[woodchuck2]

Well i cleaned it up the best i could, i filled up the hyd tank and added 1 gallon of Lucas oil treatment. I ran it about an hour last night at full throttle and worked the hell out of it. I can still smell oil intermittenly but no visual leaks as of yet. The machine seems to have a little more power now too. The temps were also about 15-20 deg colder last night too so i am sure that had something to do with it. I will be digging in a brook tonight that got washed out several days ago from the 4"+ of rainfall we got. I am hoping the leak has stopped, i really dont want to be sitting in a brook for hours with any kind of an oil leak.
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Thanks for the info, the swing motor looks fairly easy to pull if this leak does continue. As far as the swing bearing seal i beleive i have to split the machine to replace that, i am sure the machining is wore causing the leak so that i may pass on that and trade the machine when my finances allow. For now i am keeping my fingers crossed.
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[strott]

As far as greasing the swing bearing goes - I grease the swing bearing every 200 hours as stated in the Kubota manual but use 5 pumps of the grease gun per 90 degress of rotation.

I grease the swing cog/gear every 50 hours the same way.

 

[woodchuck2]

Well, it has gotten worse. I ran it for about 7 hours and it went through 2 gallons of oil . I just might send it down the road here pretty quick. I have around $15k in it and i know i made at least $7k with it last year. Who knows how much money, time, and back ache it has saved me around the house here and my other home. I am thinking of putting it in the local want-ad for $10k OBO to see if i can be rid of it. This will be the last grey market machine i ever buy, too hard to get parts for and shipping can kill yah. I have a line on a 2006 Bobcat 311 with 1500 hours. It is a rental at a friends local hardware store and i was told i can get it for $16k, he may also help me out with the financing too if i cant swing the whole cost. Time will tell, thanks for the info guys.

 

[finaldrive]

you went through two gallons of hydraulic oil?

Have you had any other problems with the machine? If not then I still say that it's not too bad off. All depends on you of course. I take it this is the machine you have referenced in your sig? The Sumitomo Mini?
Do you have the exact model and serial number of your machine?

 

[woodchuck2]

Yeah its the one in my sig. Its a Sumitomo mini SH-38 UJ, i dont have the serial# right off. Its been a decent machine for the hours that are on it. It has some typical loose pins/bushings, the glow plug module doesnt work properly in the warmer weather and the fuel shut down solenoid burnt up so i modified it to a manual. I have a new shut down solenoid for it but the harness is totally fried and am not sure how it was wired. This is the first major leak that it has had. I had a small leak develope this winter on the dipper but it comes and goes and it only seeps so i have left it alone. This leak i have now isnt too bad until you start working the drive motors, it may be a minor repair but finding the correct seals and then doing the initial repair is just something i dont have time for right now. I dont mind running the machine with a leak for the most part but alot of my work lately is around brooks, streams and my next bigger job will be on a lake. The last thing i need is ENCON showing up with a book of fines for leaking oil into the lake surrounded by tree huggers.

 

[finaldrive]

I hear ya...now that you've expanded a little more about the leak and the fact that it acts up when you use the drive motors it sounds like it's your center swivel, aka rotary manifold. Another pretty easy fix, but I understand with regards to the seals and availability. Best of luck to you.

 

[woodchuck2]

Thanks, i should have explained more from the get go but end up writing these long stories as it is when posting/replying. If the parts were easier to get and i had more time i would tackle this repair but i guess it is time to move on to something newer with fewer hours. This would make a great machine for someone who putters and has the time to repair it.

 

[willie59]

Thanks, i should have explained more from the get go but end up writing these long stories as it is when posting/replying. If the parts were easier to get and i had more time i would tackle this repair but i guess it is time to move on to something newer with fewer hours. This would make a great machine for someone who putters and has the time to repair it.

I feel ya', and don't blame you a bit for wanting to get something more "parts friendly". But consider this; that hyd swivel is going to have an effect on how much you get out of the machine when you go to sell it. The cost of the parts to repair a swivel, if you can find them, is relatively low, compared to how much it knocks off the value of the machine for something that slobbers oil. I haven't read the entire thread and I don't know who you have tried to get parts from, and I'll admit, I haven't tried to get parts for Sumitomo, but I'd really think about repairing that swivel and clean the machine up before I try to sell it. The market is full of used machines right now, and one that slobbers oil is not a hot item. I'm just thinking about your wallet here.