Single Acting Hydraulics

[Lost Farmer]

I purchased a new to me M6800. I am trying to run a new idea 5408 disc mower. The mower has a single line hydraulic cylinder. I can not get the boom to lower from the transport position.

The tractor had a self canceling detent remote and I added float detent remote thinking that was the problem. I have added a line to the other side of the remote and plumbed it back to the reservoir.

I have a 584 IH that operates the mower as it should so the problem has to be in the tractor. I have attached a disc with double acting cylinder and it works fine on that. I have Kubota scheduled for a service call next Wednesday, but thought I'd ask here to see what I could find out over the weekend.

 

[TheOldHokie]

I purchased a new to me M6800. I am trying to run a new idea 5408 disc mower. The mower has a single line hydraulic cylinder. I can not get the boom to lower from the transport position.

The tractor had a self canceling detent remote and I added float detent remote thinking that was the problem. I have added a line to the other side of the remote and plumbed it back to the reservoir.

I have a 584 IH that operates the mower as it should so the problem has to be in the tractor. I have attached a disc with double acting cylinder and it works fine on that. I have Kubota scheduled for a service call next Wednesday, but thought I'd ask here to see what I could find out over the weekend.

I assume the mower has one hydraulic hose. It should work fine if connected to one rear remote outlet on the tractor.

I think there is more to this story than you have told us.

Dan

 

[Lost Farmer]

I assume the mower has one hydraulic hose. It should work fine if connected to one rear remote outlet on the tractor.

I think there is more to this story than you have told us.

Dan

I have tried to explain it all as best I can. You're correct it does have one hose on the cylinder.

 

[TheOldHokie]

I have tried to explain it all as best I can. You're correct it does have one hose on the cylinder.

Post a picture of your hookup. My first thought is the quick couplers on the hose and tractor are incompatible or you don't have them connected.

Dan

 

[Lost Farmer]

Post a picture of your hookup. My first thought is the quick couplers on the hose and tractor are incompatible.or you don't have them connected.

Dan

I will get pics next time I'm at the farm.

I thought fittings may be a problem, so I took one off the disk I mentioned and still had same problem. I've talked to numerous people and everyone says the same thing you did, it should work.

 

[TheOldHokie]

I will get pics next time I'm at the farm.

I thought fittings may be a problem, so I took one off the disk I mentioned and still had same problem. I've talked to numerous people and everyone says the same thing you did, it should work.

Its easy to test and does not require a high dollar service call.

Dan

 

[Lost Farmer]

Its easy to test and does not require a high dollar service call.

Dan

I'll get some general pics of the setup and fittings. Anything specific you're looking for?

 

[TheOldHokie]

I'll get some general pics of the setup and fittings. Anything specific you're looking for?

Part numbers on the male coupler tip.
If you can get to it same for the female half.
Picture of the cylinder and hose.

This should be as basic as it gets.

Dan

 

[Kennyd4110]

Are you operating the control "the other way" to get it to fall? The pump will go into relief (engine lugging some) while its held there, but that should allow the oil to escape the cylinder and go back to the tank.

Did you try the other coupler and moving the handle the other direction?

 

[whitetiger]

 

[TheOldHokie]

View attachment 178393

Thats a useful feature!. But the valve will still operate the SA cylinder in DA mode and deadhead the other side- no?

Dan

 

[whitetiger]

Thats a useful feature!. But the valve will still operate the SA cylinder in DA mode and deadhead the other side- no?

Dan

I have not messed with a single-action cylinder on the older M series, but I do remember hearing that some models will not lower unless the valve is turned counterclockwise. The hose also must be in the spool-side coupler
It looks like it should lower, but due to some strange phenomenon, it won't.

 

[PoTreeBoy]

The diagram for that valve shows a separate N passage with no check valves. But the description refers to some check valves. I wonder if there's a load check in that B valve passage that the selector valve bypasses that's not shown? I haven't tried to fully correlate the valve passages drawing with the schematic.

 

[TheOldHokie]

I have not messed with a single-action cylinder on the older M series, but I do remember hearing that some models will not lower unless the valve is turned counterclockwise. The hose also must be in the spool-side coupler
It looks like it should lower, but due to some strange phenomenon, it won't.

In SA mode that selector is rerouting the neutral circuit in one of the three positions to tank so as to not deadhead the pump. Its basically a 3 way valve.with tandem center spool.

In DA mode it should operate just like a standard 4 way 3 position directional valve with tandem center spool.

I would like to read the full WSM description of that remote. J would also like to know if the OP has the valve in SA or DA mode.

A DA directional valve with a tandem center spool will operate a single acting cylinder from either work port but the pump will be deadheaded during the lower operation.

I am wondering if the problem here is the work port the OP is using???

Dan