MX6000 - FEL and 3PH Stopped Working

[BackRoad]

Threads with no resolution updates are a pet peeve...

For this one, everybody who commented gets fifteen gold stars!

Isolated to....(drum roll please)...the 3rd function!

You guys hit it dead center!

Separately, Mr. Brian (MntViewRanch and FitRite TnT) suggested shutting down the tractor, and turning the key to On...then depress the 3rd function Open and Close buttons to listen for the solenoid to click.

Restarted the tractor and the sequence successfully reset the solenoid and restored the FEL and 3PH hydraulic operation!

If you were here, I would have bear hugged each of you!

For now the 3rd function is still intermittently blocking, but I know how to clear it now, so still a handicap, but the tractor is no longer a paper weight.

With it isolated to the component (and not the main pump!!!) the next step is to determine whether it's serviceable.

Thank You to all who commented so accurately.

 

[oldnslo]

Thanks for posting the resolution to your problem.

Depending on the style of 3rd function valve their may not be many serviceable parts besides the coils. Do you have test light or volt meter? If confirm that you are getting full power to the coil to shift the valve and that there in no power to the coil when it is supposed to spring center. Stray or lingering voltage can prevent spool from centering or low voltage can prevent shifting which sounds like what is happening.

 

[Harry in Ky]

That's fine for today, but you know you have an unreliable component. Down the road, sooner or later it will do that again (or worse) and you may not catch it in time to save the damage it can/will cause. You don't know yet what the "warranty" will cover in this case. They usually try to duck the issue by blaming someone or something unrelated to their product.

 

[Dennis Mohn]

On most tractors, and I believe this one too, the steering pump is what feeds the HST.

Also, on this tractor, it uses a tandem pump. One section for the loader, remotes and 3 pt and the second, smaller section for the steering, HST and PTO valve on some tractors.

At first, I thought it stripped the splines on the pump input shaft but since it's a tandem pump and you still have HST and steering (I assume), this is not the case as the same driveshaft drives both sections of the pump.

After the bigger pump, it goes to an hydraulic block that then feeds the loader valve. On this block, the only thing that could possibly go wrong is the relief valve. Maybe some trash managed its way through and the relief valve got stuck open.

This would be my first go to component to investigate as it would cause the loss of loader, remotes and 3 pt.

Here is a parts view of the hydraulic block. Part #80 is what I suspect is stuck open. Or, although very unlikely, the spring #70 broke.

View attachment 882928

My thoughts exactly , in a system like this check the relief valve first then possibly the detents.

 

[bgr]

A quick check to make before getting into things is to make sure that all your hydraulic hose connectors are fully latched into place. Disconnect and reconnect them. Your pump is OK because hydro is working and steering has boost.

Your 3 function valve and grapple probably are on a power beyond hose with connectors and one connector is not fully latched into place, so no oil flow to operate them. Sounds like the return connection is still in place but check both.
If connectors OK, something is blocking the power beyond flow to your valve stack.

If you were working in brush, a stick could have poked a connector and partly released it. A connector can be partly released and blocking oil flow without looking like it is released. Usually won't leak oil either.

Not hard to do a quick check.

 

[BackRoad]

Thanks for that Mr. BGR. I cleared the issue, so the tractor hydraulics are working again, but did not fully isolate the root cause within the 3rd function components yet.

We had family in, but I finally have some time over the next couple of days to get into the details, including the QCs as you mention.

 

[BackRoad]

Swapped (rolled) the original QCs at the valve.

Since the "close" function was at fault:
- If the issue stayed with the close function, then the root issue is the valve.

- If it moved to the "open" function, the issue is with QCs or the lines to the grapple.

Then I went out and pushed over a 12 inch diameter Poplar that was dieing. Bucked it up and carried it off to the slash pile...so ~30 minutes of grapple usage.

And of course...NO issues with the hydraulics throughout the process! Bummer, and yet slightly optimistic at the same time!

For now, all is working as normal. Logically, I should return the QCs back to the original configuration to see if the issue returns, but I may actually end up leaving them as-is for the long-term.

I've got 2 full days of grapple work to do at church in the next couple of weeks...we'll see if I can re-educate my fingers on the swapped open/close functions and if the issue returns!

And another big "Thank You" to the guys who didn't think it was the main hydraulic pump!!!

 

[BackRoad]

And now hopefully, the rest of the story...

Problem came back as anticipated and stayed with the close function...so, time for open heart surgery.

Disconnected the 3rd function valve and put it on the bench.

Disassembly was straight forward.

Found a thin, sliver of metal holding one of the valves open. It was stuck in one of the flow control openings, wedging it partially open.

It was intermittent, working normal at times...then when wedged in place, the hydraulics stopped working.

It's back together and working once again.

Tomorrow is a full day of clearing with the grapple, so we'll see if it is 100% resolved.

1st pic is an internet image, but it is very similar to the actual. The piece of metal was sticking out one of the tiny holes, wedging the inside diverter open.

2nd and 3rd pics show the actual piece of metal...looks like a left over splinter from a casting, or something similar.

It was a clot, plaque build-up, a foreign particle in the blood stream, errr, I mean hydraulic stream, and the Kubota did not even get the Covid shot!

So of course...wondering now where it came from...!?!?

 

[rScotty]

The first sentence holds the key. The grapple wouldn't stay open. That's by no means a pump related problem. Next clue is the "button". That says there is a solenoid valve somewhere in the mix. My bet is the bulk of the problem is right there.

Either that or the associated relief valve. Agree that the first sentence and the five minutes hold the key.

Reminds me of the BH swing problem on the Kuboa M59s.

If it is similar, forcing the grapple to move while rapidly working the solenoid might get it working again.

Read some of the similar Bh swing threads.

rScotty

 

[rScotty]

I just realized where that metal could come from, how to fix it, and even why it didn’t affect anyone’s HST. ….and i had all the info since about 2014 but just now put it together.

When I changed my hydraulic filter back then, the pipe nipple that the main hydraulic filter mounts onto fell out into the oil pan with the filter attached. It hadn’t leaked because it was still screwed into the filter canister base, and that allowed the main filter base gasket to seal. It was tightly to the transmission case, so no concerns there.

But as i looked at the part, i realized it was the same type as a cheap hardware NPT plumbing water pipe nipple - much just like you buy at Home Depot or any discount hardware for a dollar. Crappy threads, welded iron pipe, loose trash swarf, and not even deburred. That explained the poor tighten into the tranny - probably because of the poor threads and the burrs.. All the rest follows. Affixed, polished, rethreaded, and loctited with appropriate torque. No more problems.

The HST has an additional downstream fine filter which must have caught any swarf headed to the HST before it could get into the tight HST clearances. Thankfully.

But the main bulk of swarf had to make one circuit before being filtered - my guess is some of the metal particles got caught in the wrong places during that circuit.

rScotty