kubota bh77 dipperstick cylinder problem

[Smokeydog]

Frustrating problem. The mechanical interference with the handles is obvious.
I have had temporary lost control of two circuits, boom and left swing, on the BT1200 backhoe a few times. The cause is debated and no clear answers. Hard to pin point the cause when it goes away.

I suspect air being pulled in from the quick disconnects or fittings and then interfering with the relief valves somehow. Had a slight leak at tractor side nipple to QD on the tractor side backhoe supply side. Since fixing that leak, haven’t had problem again. Too early to tell if that is a permanent fix. Doesn’t explain the swing side since it has its own supply and common return.

Interested in your resolution.

 

[rScotty]

Frustrating problem. The mechanical interference with the handles is obvious.
I have had temporary lost control of two circuits, boom and left swing, on the BT1200 backhoe a few times. The cause is debated and no clear answers. Hard to pin point the cause when it goes away.

I suspect air being pulled in from the quick disconnects or fittings and then interfering with the relief valves somehow. Had a slight leak at tractor side nipple to QD on the tractor side backhoe supply side. Since fixing that leak, haven稚 had problem again. Too early to tell if that is a permanent fix. Doesn稚 explain the swing side since it has its own supply and common return.

Interested in your resolution.

Someday we are going to figure out what makes these larger size Kubota backhoes go into "limp mode" for no reason.... and why they then spontaneously recover.
I've forgotten - or maybe never knew - but have you had similar problems with the B26?

How did you get smart enough to end up with both a B26 AND an M59? Which one gets the most hours?
rScotty

 

[Smokeydog]

Someday we are going to figure out what makes these larger size Kubota backhoes go into "limp mode" for no reason.... and why they then spontaneously recover.
I've forgotten - or maybe never knew - but have you had similar problems with the B26?

How did you get smart enough to end up with both a B26 AND an M59? Which one gets the most hours?
rScotty

No problems with the B26 backhoe. Each tractor gets ~100hrs use per year in our caretaker/landscaper mode. Don’t do much farming anymore and treat our place more like a park. Both spend approximately 80% in 3pt mode. Both were bought used, 50hours on the B26, 1,100 on the M59. My wife puts more hours on the B26 than I. Decades of trial and errors of other machines makes that choice a safe option. Having both tractors that operate vary similarly helps helps me particularly in our Golden years. We want to do as much as we can while we can.

 

[DB Pilot]

I do not think the levers hit the frame anywhere. I will try to check that out for sure on Thursday. One symptom the Mechanic showed me was the dipper stick moves an inch or so and then springs back. And of course its not supposed to do that at all after extending. :thumbdown: nbryan thanks for the pictures. They give me specific things to look for.

 

[fried1765]

No problems with the B26 backhoe. Each tractor gets ~100hrs use per year in our caretaker/landscaper mode. Don稚 do much farming anymore and treat our place more like a park. Both spend approximately 80% in 3pt mode. Both were bought used, 50hours on the B26, 1,100 on the M59. My wife puts more hours on the B26 than I. Decades of trial and errors of other machines makes that choice a safe option. Having both tractors that operate vary similarly helps helps me particularly in our Golden years. We want to do as much as we can while we can.

I use my L48 TLB, and my Ford 1920 the same way.
Just for play!
I am already too old to do any real work, but I do still love to play!
I use them WAY fewer hours than you do.

 

[ProjectKing]

I do not think the levers hit the frame anywhere. I will try to check that out for sure on Thursday. One symptom the Mechanic showed me was the dipper stick moves an inch or so and then springs back. And of course its not supposed to do that at all after extending. :thumbdown: nbryan thanks for the pictures. They give me specific things to look for.

It kinda sounds like it may have a pinched hydro hose or collapsed hose. Strange problem

 

[rScotty]

I do not think the levers hit the frame anywhere. I will try to check that out for sure on Thursday. One symptom the Mechanic showed me was the dipper stick moves an inch or so and then springs back. And of course its not supposed to do that at all after extending. :thumbdown: nbryan thanks for the pictures. They give me specific things to look for.

Reading back through this entire thread, I don't see anywhere that the cylinder was taken apart to have a look. If not, that's the obvious place to start.... and not very difficult to do.
An alternative is just to disconnect the offending cylinder and attach the hoses to a spare cylinder of any type and see if that one moves properly in response to the control valve.
rScotty

 

[DB Pilot]

I went down to the shop to look at the controls and nothing is touching anything. :thumbsup: talked to the Mechanic and he is convinced it is in the "lower relief valve" for that control. Kubota parts have been ordered. Please don't quote me on what I was EXACTLY told as hydraulics are not my strong point. As to the cylinder, it was tested with air not hydraulic fluid and worked back and forth easily. No pinched hoses have been noticed.

 

[rScotty]

I went down to the shop to look at the controls and nothing is touching anything. :thumbsup: talked to the Mechanic and he is convinced it is in the "lower relief valve" for that control. Kubota parts have been ordered. Please don't quote me on what I was EXACTLY told as hydraulics are not my strong point. As to the cylinder, it was tested with air not hydraulic fluid and worked back and forth easily. No pinched hoses have been noticed.

Well, that relief valve is certainly a possibility. I suspected the same thing back ten years ago when our M59 - along with several others - began to show the "on again/off again" behaviour of the swing cylinders that is still an M59 mystery.

So I sure can't fault the mechanic for his guessing the relief valve... especially since I not only did the same thing, but was so sure of my guessing diagnosis that I ordered not one, but both relief valves. And both brand new valves are both still sitting on the shelf in their Kubota parts box. Before they arrived, that "on again/off again" mysterious swing valve problem fixed itself.

Bottom line is I was a little too lazy to take the relief valve apart and look... plus a LOT too lazy to take the cylinder apart and look.... and A WHOLE LOT reluctant to go buy or make a flow meter which would have answered all those questions and more in about half an hour. I got lucky and it fixed itself. Doesn't sound like yours is going to do that.

But like I said, I don't fault him; I did the same thing & maybe he will be right this time. Hope so.
rScotty

 

[Smokeydog]

Be sure to keep your old parts and ask if they can show you the malfunction.

Like many others have mysterious ghost in the machine that comes and goes. Like a stuck relief. Air? Friction or back pressure from trapped air?

Hope that permanently fixes your problem and have some answers.