3 pt. won't stay up

[Bird]

Re: 3 pt. won\'t stay up

Well, that's another new one to me, but it ain't the first thing I ever learned on this forum./w3tcompact/icons/smile.gif

Bird

 

[Von]

Re: 3 pt. won\'t stay up

Chris, Could it be that the there are two seperate systems, one for the trans and one for the hydro. to run the 3 pt. I had a old Oliver that was that way. It had two dip sticks, one for the trans. and one for the 3 pt. and they used different types of fluid. This tractor was a bit older (1959) but could have been the same type of set up. Just a thought.

Von

 

[MChalkley]

Re: 3 pt. won\'t stay up

Chris, have there been any further developments on your problem?

If the oil is foamy, then it's been contaminated with something, most likely water, and has emulsified. It has to be drained and discarded, and the cause of the contamination found and fixed.

That could also be the cause of your hitch not staying up. Foamy oil won't hold pressure.

Mark

 

[Rch]

Re: 3 pt. won\'t stay up

Gear oil vs hydraulic fluid; in the 1980s a hydraulic system was considered an add-on and the tractor manual was for a bare bones tractor, thus the recomendation for 80/90 gear oil. I have a 1986 Iseki and the manuel reccomends 80/90 gear oil. Its has a FEL with attendent factory installed hydraulic pump an reccomends hydraulic fluid in the FEL manuel

RCH

 

[Chris]

Re: 3 pt. won\'t stay up

RCH: after reading your post, I remembered that my manual did have a section on installing the 3 pt. hitch. I was hoping that when I read it, it would tell me to replace the gear oil in the tranny with UDT after adding the 3 pt., but no such luck. It looks like the hydraulic system came with the tractor, and the instructions were for adding the 3 pt. lift arms, chains, etc., not adding the hydraulic system. You say your add-on loader uses hydraulic fluid? Mine calls for Type "F" automatic transmission fluid. Thanks for the response.

Chris

 

[Chris]

Re: 3 pt. won\'t stay up

Mark: I have been out of town all week (was posting from the hotel room), and just got home this evening. I plan to do a little more investigating this weekend. Does Steve Carver still post here? I haven't seen anything from him in a while. I think he may have been a Kubota dealer when this machine was new, so I'd be interested in hearing his thoughts.

Chris

 

[Chris]

Re: 3 pt. won\'t stay up

wen: I still have the stuff I originally drained out (haven't been to the local recycling center to see if they will take it). I just got 3 cups and poured some fresh gear oil in 1, the old fluid in 1, and some UDT I happened to have (for my hydrostatic garden tractor) in the 3rd one. After comparing their characteristics, I believe the tractor had UDT in it to begin with. I think this weekend I will drain it again, and fill it up with UDT and see what happens. Then, as you suggested earlier, I'll change it again after 4 or 5 hours of use. I may also thake this opportunity to try and replace the seal that I believe is leaking that causes the thing to leak down when cold. Thanks for all your help.

Chris

 

[W5FL]

Re: 3 pt. won\'t stay up

You are welcome Chris,

Let us all know how you make out.

Once, early in my career, I had the opportunity to design a hydraulic rotary actuator. I got to run it for all the original testing in a hydraulics lab. I just could not visualize using 90W gear oil in a 3000 psi pump or actuator?

There has always been a problem with getting a fluid that performs well under high pressure, provides lubrication to the metal parts, does not foam, picks up easily for the pump, and does not turn to carbon under the high heat present. There is a reason why there are so many different hydraulic fluids in automatic transmissions, although the industry has about come up with a universal fluid now. Tractor manufacturers came up with a universal fluid (called UDT by Kubota) that primarily only differs now in whether it is formulated for wet disc brakes to operate in the fluid.

 

[Chris]

Re: 3 pt. won\'t stay up

This afternoon I drained the gear oil and replaced it with UDT. After a little use, the 3 pt. stayed up like it did before I changed the fluid. I also went to the closest Kubota dealer to buy the "o" rings to replace in my control valve. The dealer did not stock any of the "o" rings or gaskets I need. He ordered them, and I will have to go by next week and get them. I plan to use the tractor this weekend, then change the fluid again next weekend to be sure I got all the gear oil out. While it is empty I will remove the control valve and replace the "o" rings. With a little luck, after next week it will stay up ALL the time, not just after it warms up. I am glad to have the mystery solved, and to be back to the status quo. Thanks again for all the insight and ideas from everyone.

Chris

 

[W5FL]

Re: 3 pt. won\'t stay up

Glad you got it going again. You were just pumping lots of air and that made the oil very foamy. It was too thick to displace the air and you never got any real uplift pressure. Glad they are getting you the o rings - hope that fixes the rest of your problem. /w3tcompact/icons/smile.gif