Kubota loader becomes anemic when hot

[wsc9tt]

So I have a 2015 Kubota MX5100HST that has about 100 hours of light use. Lately, I have been doing some digging and I find the front hydraulics lose power and moves very slowly after it has been working hard for 30 minutes. I assume that is when the fluids are all hot. First I checked the radiator and did find that it was rather gunked up with grass, but after cleaning that all out the symptoms still exist and when the problem occurs I find that I can put my hands on both the radiator and the HST radiator so I don't think anything is that hot. The guage also seems fine.

Before I take it to the dealer I thought I would try to fix any obvious problems to save myself some money. At the 50 hour service, I changed the HST filter but the Hydraulic oil filter isn't scheduled to be changed until the 400-hour service. I thought about doing that now, but I don't want to buy 11 gallons of new UDT oil.

Suggestions on what could be causing this problem and what I should try?

 

[Leejohn]

Could be you are sucking air after it gets warm. Check the suction line to the hyd pump. There is a small rubber hose that hooks the steel line together, check for cracks and lose clamps.

 

[wsc9tt]

Those lines all seem new and I don't see any issues. I should probably take it to the dealer.

 

[teg]

...I changed the HST filter but the Hydraulic oil filter isn't scheduled to be changed until the 400-hour service....

Not 100% sure of your model but the hydraulic oil usually isn't changed until 400 hours but BOTH hydraulic filters should have been changed out.

PS. The return hose can "look" new when they are cracked. Squeeze them and if they are cracked, it will show up, usually on the outside bend. BUT that problem was fixed a while ago and mainly it was for the economy L's.

 

[Oldoak]

There is no way those hoses should be bad on a 2015 Kubota with only 100 +/- hours. My 19 year old Kubota still has all it's original hoses, and have been problem free. Unless Kubota has cheapened their product line...........

wsc9tt, I would call the dealer first and see if they could recommend a solution to your problem, before taking the time and expense of hauling your tractor to the dealership.

 

[oldnslo]

Does the curl function and the 3 point hitch work when warm? If yes then the problem is in the lift circuit of your FEL.

Typically slower speeds / loss of pressure when warm is do to the oil by-passing or leaking some where.

 

[wsc9tt]

The dealer suggesting trying to change the main hyd oil filter first. Just swap it quickly and I shouldn't lose too much oil.

 

[teg]

use the shop vac trick!!! stick sv hose in the inlet

 

[birddog0304]

Ditto on what teg said. Used that several times. Couldn't believe it the first time. One of the coolest tricks ever and didn't waste more than a cup of hydraulic oil

 

[oldnslo]

Does the curl function and the 3 point hitch work when warm? If yes then the problem is in the lift circuit of your FEL.

I never saw an answer to the question about the curl or 3 point.


I will be surprised if changing the filter makes a difference since warm oil flows easier than cold so it would pass through the filter much easier when warm.

 

[nybirdman]

Try lowering the three point hitch a little and see if that cures the problem.If not adjusted right it goes into relief and causes all kinds of hydraulic problems.Took three trips to the dealer and the district rep. to find mine.

 

[wsc9tt]

UPDATE:
So I swapped the filter and yesterday had another case where I needed to make heavy use of the loader. I trenched a drain tile because it was simpler than renting a trackhoe.


Well, actually the problem didn't start occurring until I got stuck in the woods and was really using the loader to try a drag myself out of that mess. ;-)


So again the loader starting operating very slowly. And to answer some previous questions, only the raise and lower functions of the loader where impacted. Curl seemed fine and the 3-pt still worked fine. I didn't have the grapple attached so I don't know about the 3rd function. After I took a break for 30min the loader was back to working fine.

Try lowering the three point hitch a little and see if that cures the problem.If not adjusted right it goes into relief and causes all kinds of hydraulic problems.Took three trips to the dealer and the district rep. to find mine.

This is very interesting. I can say that every time I hit this problem I was only using the box blade on the back for ballast and I had it at the highest position to keep it out of the way. I will try lowering it some next time. Was there a fix for your problem or just don't use the very top of the 3pt?

 

[nybirdman]

There is an adjustment( a limit switch I believe).On mine I can hear a high pitched squeal when the three point is all the way up,and it sure does make the all the hydraulics act funny.

 

[Leejohn]

If your feed back adjustment is off and with the 3pt is up you are heating the hyd oil way up. Look in your manual for the info on how to adjust it.

 

[art]

You do need some adjustments and the tractor still should be under warrantee. Try and work with him. The three point could be the adjustment that is off and it was in the books as to how to adjust.