Yanmar 240 Loader Hydraulic issue

[jb92563]

I was using the loader on my Yanmar 240 and a had just raised the bucket and dumped the load and suddenly the bucket controls ceased working with the bucket in a raised position.

I can not raise or lower the bucket or move the wrist, not even under its own weight to lower.

I checked the hydraulic oil reservior and it may have gone below the hydraulic pumps pickup.

I added oil and still nothing is working.

Is it possible to loose hydraulic oil prime in the pump?

There is an oil filter at the controls that I will check.

I am not familiar with the Hydraulics so I am not sure where to check.

Perhaps there is something in the controls that needs cleaning.

Its odd that the failure was so sudden and complete, which leads me to believe that perhaps something is stuck in the controls, even though I am able to operate the levers without any noticeable change.

The aux hydraulic loader pump that operates off the front of the engine seems to be turning fine so its not the engine coupling.

How should I go about debugging this?

 

[Soundguy]

bottom line, even if you had removed the hyd pump.. the loader should LOWER under gravity pressure when you open the dump port.

thus it has to be a valving failure or oil stoppage, or mechanical hangup.

if you have any quick disconnects, and one of them came loose, that COULD be the issue.

next, make sure the loader control linkage really is moving the spool in the hyd valve.

lastly.. look for something mechanical that could be hanging the loader up.

my bet is option 1 or 2 vs 3

 

[jb92563]

I'm thinking the valving/blockage too as normally the bucket will lower on its own in a day or two and so far it has not budged an inch after 2 days.

Thanks for the suggestion. Not being familiar with tractor Hydraulics yet I was not sure where to start.

 

[284 International]

There is a key on the shaft of the pump. This can wear or fall out, and will let the chain coupling spin normally but not power the pump. There is a hex drive set screw that is supposed to remove all the slack and locate the shaft, but that can loosen too.

I would look there first, because the "suddenly quit working" portion is a clue that something immediately changed, rather than the typical gradual weakening/slowing of a clog.

If you look very closely you will be able to see the actual shaft of the pump. Make sure that is turning when under power; as an aside be very careful crawling around or just generally being near or especially under the elevated bucket. Entropy suggests it will, eventually, fall...at whatever rate. Watch out for kids/pets/careless people doing the same.

 

[winston1]

It should lower whether the pump is working or not. Any change in sound when moving the lift lever or curl lever with engine running?

 

[clemsonfor]

Yea if no fluid or working pump it would lower when the valve was opened.

And unless you lost all your fluid you cant go below the pickup..its basically the bottom of the sump.

I think you have a stuck valve in the control. i would remove it and take it apart, looking for trash to clog passeges or seize the control.

 

[Leejohn]

You should block that loader somehow or bleed it down.

 

[jb92563]

Yea if no fluid or working pump it would lower when the valve was opened.

And unless you lost all your fluid you cant go below the pickup..its basically the bottom of the sump.

I think you have a stuck valve in the control. i would remove it and take it apart, looking for trash to clog passeges or seize the control.

I can move the control levers as normal so when you say stuck valve, isn't the valve directly connected to the lever, and hence you can "feel" if it was stuck?

Also, I lost both functions at once which seems logical if they are in series and something got plugged upstream.

The not leaking down as normal is perplexing and I wonder if that indicates anything.

 

[jb92563]

It should lower whether the pump is working or not. Any change in sound when moving the lift lever or curl lever with engine running?

No change in sound when operating the levers so it seems its not getting fluid movement at all.

 

[jb92563]

There is a key on the shaft of the pump. This can wear or fall out, and will let the chain coupling spin normally but not power the pump. There is a hex drive set screw that is supposed to remove all the slack and locate the shaft, but that can loosen too.

I would look there first, because the "suddenly quit working" portion is a clue that something immediately changed, rather than the typical gradual weakening/slowing of a clog.

If you look very closely you will be able to see the actual shaft of the pump. Make sure that is turning when under power; as an aside be very careful crawling around or just generally being near or especially under the elevated bucket. Entropy suggests it will, eventually, fall...at whatever rate. Watch out for kids/pets/careless people doing the same.

I was looking at the chain coupling that was turning but could not see if the pump shaft itself was turning, dark, obstructed and dirty area. Perhaps a shot of dayglo orange to that area would help.

I'll have to take a closer look as that could explain the situation except for the lack of the usual leak-down after a couple days.

 

[winston1]

Never answered about quick connect fittings on the hoses. Do you have any?

 

[Soundguy]

Pump turning is a wild goose chase.. The loader should drop when the valve opens..

Thus:

Valve is stuck

Hyds are deadheaded both directions, lil from a pair of uncoupled qd's

Mechanical loader linkage jammed solid

 

[Markey]

You should block that loader somehow or bleed it down.

YES, YES!!! PLEASE block (support) the loader or bleed down!!! You mentioned that it suddenly stopped in the up position. Well, it can also suddenly and unexpectedly drop too with dire consequences if someone happens to be near it if it would suddenly fall. We want you posting on the forum for a long, long time.

 

[kenmac]

Pump turning is a wild goose chase.. The loader should drop when the valve opens..

Thus:

Valve is stuck

Hyds are deadheaded both directions, lil from a pair of uncoupled qd's

Mechanical loader linkage jammed solid

I'm with u.. I say something is wrong with the loader valve (internal) not moving the valve to lower the loader

 

[clemsonfor]

Sound guy and the valve guys could be right...but if the lines were deadheaded the pump would of sheared or done it by now if it didnt when it stopped working.

I think there is trash or crud stuck in that valve somewhere?

Not a hydro expert or even want to be. But can a colapsed hose casue anything remotely similar?

Maybe one of the Cylinders has internally destroying itself seizing the loader inposition? i dont know just throwing out ideas.

 

[Soundguy]

i think i'd block the loader and use a jack to tape pressure off, and then undo hoses and get a bucket.

then run the controls thru their range and see if the proper hoses swap between dump and lift, depending on which way the spool is pushed.

 

[jb92563]

Never answered about quick connect fittings on the hoses. Do you have any?

No quick connects.

Now that you mention I did have issues lowering the bucket on occasion and cycling the valve back and forth a few times cleared it.
I just assumed that is was mechanical sticking but it may have been a precursor to the complete failure its in now.

Not to worry about the raised bucket danger, I know that farm implements and machinery will take pieces from you or worse the at the slightest dumb mistake. That's why there are no old slow dumb farmers, only the quickest, smartest and luckiest are able to survive the onslaught of the machines. That said I have a nice stump to support the raised bucket till I can bleed the hydraulics slowly to lower it.

Thanks for the concern and tips, I think I'll focus on the control valves first.

 

[Soundguy]

deffinately prop up and do the bucket test...

that will tell you if you have flow, and what the valve is doing.

if you have flow, and the valve is working, but the laoder won't drop.. then look at a mechanical hangup locking the loader in place despite hyd effort to move it.

post back details.

remember. even with no pump, moving the stick to dump SHOULD drop the loader, assuming hte valve is making it to dump and nothing mechanical is hanging it up.

 

[winston1]

I agree with soundguy's advice.

 

[clemsonfor]

i think i'd block the loader and use a jack to tape pressure off, and then undo hoses and get a bucket.

then run the controls thru their range and see if the proper hoses swap between dump and lift, depending on which way the spool is pushed.

NOt knowing hydros i was thinking of this as well. Suport that bucket and loosen to see if and where there is fluid, plus this will allow you to get bucket down if you want