Kubota M5700 hydraulic pump

[Kubman37]

I recently bought my first Kubota M5700 4wd Rops from an individual. I have noticed when working the 3pt hitch there’s a lot of travel and small movement that actually controls the lift. What I’m really concerned about is when I pick bush hog all the way up they hydraulic pump wont cut off unless you move the position control lever down about a inch or so then you can hear the pump cut off. Is that normal or is there some kind of adjustment to make the pump cut off when it’s lifted all the way up? Thanks for the help.

 

[RCW]

I’m guessing when you bring the 3PH right up to the top stop the pressure relief may be activated. Won’t stop until hitch lowered a little.

Another real possibility is that the hitch needs the feedback rod adjusted that controls travel for top end limit…something to consult a Workshop Manual for

 

[Kubman37]

Correct if I lower it a little it will stop and have tried adjusting the feedback rod both directions and doesn’t stop the pump from running when picked all the way up unless I’m not adjusting in the right direction enough.

 

[Dave_eng]

Adjust feedback rod.

The feedback linkage should limit how high the upper lift arm can go so as to not keep the relief valve working.
Dave

 

[Russell King]

The linkage to adjust is the feedback rod between the short upper arm and a tab going into the tractor case. You need to lengthen it to get the squeal to stop.

steps to follow (paraphrasing from manual)
Raise arms all the way.
Loosen the two nuts.
Lengthen arm until squeal stops. (Turn the nut behind the tab and push the tab)
Then make it just start squealing.
lengthen the rod one full turn of the nut.

 

[Kubman37]

So my next question is do I extend the feedback rod or retract the rod to keep the relief valve from working?

 

[Kubman37]

Thanks for all the help will look into tweaking the feedback rod some more tomorrow evening and see if that will solve it.

 

[North Idaho Wolfman]

So my next question is do I extend the feedback rod or retract the rod to keep the relief valve from working?

You're not adjusting the relief valve you're adjusting the three point control valve.
You're adjusting the feed back rod so that the three point control knows the hitch is up and shuts off.

 

[TheOldHokie]

I recently bought my first Kubota M5700 4wd Rops from an individual. I have noticed when working the 3pt hitch there’s a lot of travel and small movement that actually controls the lift. What I’m really concerned about is when I pick bush hog all the way up they hydraulic pump wont cut off unless you move the position control lever down about a inch or so then you can hear the pump cut off. Is that normal or is there some kind of adjustment to make the pump cut off when it’s lifted all the way up? Thanks for the help.

To be clear the pump is driven directly off the engine. It runs continuously pumping oil in a loop and never shuts off.

What actually happens is moving the 3pr lever operates the control vakve to divert that constantly circulating oil to the lift cylinder which raises the lift arms. When the arms reach the top of travel a mechanical linkage (feedback rod) is supposed to automagically bump the control valve back to neutral position where the oil is allowed to circulate freely. If that does not happen the diverted oil flow is deadheaded into the lift cylinder and the relief valve is actuated to prevent over pressurizing the pump.

Dan

 

[Kubman37]

Ok adjusted the feedback rod as much as I could and it’s still not bumping the control valve back to neutral so the relief valve still runs. Any other suggestions on what else I could look at?

 

[TheOldHokie]

Ok adjusted the feedback rod as much as I could and it’s still not bumping the control valve back to neutral so the relief valve still runs. Any other suggestions on what else I could look at?so high tje feedback linkage

Adjusting the feedback should do it.

Is the lever guide plate in place? As I accidentally discovered on my L3901 when its removed the position control lever can be raised beyond the range of the feedback linkage.

Dan

 

[Russell King]

There have been reports and comments that the smaller upper arms have been removed from the shaft and installed in an different position.

I don’t know how you could verify the position but there may be some markings on the end of the shaft ends and sides of the arm that are aligned when assembled correctly.

I think you can manually push the tab (that the feed back rod is supposed to move ) and see if it would return the valve to neutral. Use a tool not a finger for safety.

is the feedback rod bent or damaged somehow?

 

[North Idaho Wolfman]

Ok there are a few points to operation that are getting mis-stated.
Adjusting the feed back lever does not cause the lever to " bump the control valve back to neutral", the control lever will not move.
Inside the case the three point control valve has an input on one side from the position control lever and on the other side from the feed back lever.
These two inputs teeter totter on the valve where as one will override the other.

Move the control lever to the 1/2 to 3/4 lift point does everything seam fine?
If not then you have other issues going on.

If it does then move the lever till it loads and does not go back to neutral.
if it's doing that then the feed back is adjusted wrong.

You need to lengthen the rod slightly, too much and it will have issues.

You can do this another way:
Remove the connection of the feed back linkage at the three point side, move the position lever to max lift then push the feed back rod forward till it stops loading.
That will give you the length the feed back rod needs to be.

 

[TheOldHokie]

Ok there are a few points to operation that are getting mis-stated.
Adjusting the "feed back lever" does not cause "the lever" to " bump the control valve back to neutral", the "control lever" will not move.

Dont you just love the English language and the ease of constructing ambiguous references? Up until now no one said the position control lever moves.

The position control lever sets the desired lift arm heght and does not move once set by the operator. Once that is set the feedback lever does move in response to changes in lift arm height and is what bumps (shifts) the control valve (spool) into and out of neutral so as to maintain that set height.

One picture might be worth a thousand ambiguous descriptions.

Dan