M59 backhoe hook operation

[c304]

How much force should be needed to get the backhoe unhooked? I'm pulling back pretty hard on 180 in the picture, but 070 isn't lifting at all, and I'm wondering if that's normal or I'm misunderstanding the mechanism.

 

[LD1]

Have you tried raising the boom?

If I am understanding correctly.....that is the boom lock for transport purposes. Because the boom cylinder will slowly bleed off (hydraulically) over time. when it does this, you have the whole weight of the backhoe being held by them hooks.

Fire it up......raise boom all the way....and it should go pretty easy.

Not familiar with the M59 though, only the smaller kubota backhoe attachments, in which the boom locks have a detent of sorts where you have to pull OUT and back on the lever. Then it rests in another "detent" to hold it in the "released" position.

 

[Peter 315]

Just like LD1 said pull the boom back then release the safety latch ,Maybe spray some oil on the pin to make sure it moves freely

 

[mljenkins]

On my BH92 it takes no effort at all to pull that lever back. As others said you must pull the boom back first and you will notice the pin that sits against the mechanism that holds the boom back about 1/2”. Then it should release with no effort at all, like you can do it with your pinky finger easy.

 

[V7Sport73]

Mine is kind of sticky on the M59 as well. Make sure the boom is all the way back. Perhaps some WD-40?

 

[Hersheyfarm]

I use to have to use the right stick to bang the boom to be able to release the lock. There was a recall on the cylinder, something about the internal cushion kept it from bottoming out enough to unlock. I had it done, they replaced the cylinder.. might check with dealer.

 

[mikester]

View attachment 549250

How much force should be needed to get the backhoe unhooked? I'm pulling back pretty hard on 180 in the picture, but 070 isn't lifting at all, and I'm wondering if that's normal or I'm misunderstanding the mechanism.

Once #170 is clear of the latch pin it lifts easily.

You need to raise the boom all the way for the catch on #170 to clear the pin its grabbing onto. If the pin is clear then your catch #170 isn't rotating on its pin and is likely seized. Get out the penetrating oil and let it soak several hours before using a hammer and a block of wood to tap and free the rotation on #170.

Once you get #170 moving I'd pull the pin on #170 to thoroughly clean it and the bore. Use lots of anti-seize when re-assembling it.

WD40 isn't really the best penetrating oil its more like duct tape when you need vise grips.

 

[c304]

You guys are fast!

I'll try moving the boom a bit after work and see if that was just putting it under tension too much. I just got the thing, so I haven't got a feel for it yet. Next challenge will be removing the backhoe and hooking up the top and tilt. I should order some gloves.

 

[c304]

It popped right off. Thanks!

Couple other questions...

Is it bad to let the boom bleed down when parked? Assuming the bucket isn't rusting in a puddle, is it necessary to lock the boom after use?

Is it better to run the engine at low or high RPM for light backhoe use? Like is it better for the life of the hydraulics to run at a certain speed or does it not matter and it's more about responsiveness vs fuel consumption?

 

[Fallon]

Run the engine as fast as needed to get the speed needed out of the hoe. Any faster & it burns more fuel & makes the hoe twitchy & jerky because it's going faster than you are.

The hydraulics aren't going to care really unless you hit relief a lot if your pump has a bit of internal leakage (they all do to some degree) you might need some extra RPMs to overcome that & get maximum hydraulic power. If the engine is a tier 4 with a diesel particulate filter it will a little. A DPF works much better at mid to high RPMs. Low engine RPMs & bogging the engine create more soot. And more soot means more filter clogging & more frequent regens. Not the end of the world as regens are there to clean & regenerate the filter. But best to kick up the RPMs some & minimize the wear.

 

[rScotty]

It popped right off. Thanks!

Couple other questions...

Is it bad to let the boom bleed down when parked? Assuming the bucket isn't rusting in a puddle, is it necessary to lock the boom after use?

Is it better to run the engine at low or high RPM for light backhoe use? Like is it better for the life of the hydraulics to run at a certain speed or does it not matter and it's more about responsiveness vs fuel consumption?

Glad to hear that worked for your boom lock. That's what I do on mine: pull the lever to move the boom back and release the boom lock at the same time. A smear of grease on the boom latch worked wonders too.

Don't know the answer to whether it is bad to let the boom bleed down. But the whole reason why something leaks down means that hydraulic fluid is seeping from one area to another. That may not be bad, but certainly can't be good. So why would you want to do that instead of locking the boom? It's surely not bad to lock it.

Uh.... on engine RPM. I confess that I like to do backhoe work with the motor only turning at a fast idle. The M59 backhoe power even at idle is awesome, and I prefer the smooth way the controls work at low to medium RPM.
To your question, of course everyone knows the principle that mechanical wear goes up with RPM just like hydraulic wear goes up with higher flow. There are counter arguments too, but I've always been a believer that on balance, lower rpm reduces wear on any engine.

But there is one area where the M59 might be part of a motor group that are the exception to the wear argument. The M59 motor was designed in an era when the Interim Tier IV pollution regulations were in effect - roughly the era 2007 to 2015. Many manufacturers - including Kubota - met those regulations with a combination of injection timing and EGR valving in a way that sometimes can create heavy sooty black exhaust on startup, low rpm, and when gunning the engine. It's not just the M59s & other Kubotas, it's the way a lot of engines from that era were designed.

If your Tier IV engine does those things - i.e. makes heavy black soot when changing speed - then I am coming to believe that prolonged low RPM use will lead to carbon buildup in those engines.
It's not a fatal flaw - and even if carbon build up happens it may not lead to anything bad. But it is a reason to run those particular engines at higher RPM for at least part of the time.
Luck,
rScotty

 

[LD1]

There is gonna be very little change in power with engine RPM's. Pressure is what makes power. RPM's make flow which is speed. So set the RPM's at a how fast you want the hydraulics to be.

I am betting that is gonna be low to mid RPM's to get started. But as you get used to the machine, I bet you are gonna start creeping the RPM's up to gain the speed.

 

[Hersheyfarm]

I run mine at about 2200 rpm's when digging trench or deep sewer holes, but 1500rpm for sketchy digging around utilities. Like said you don't get much more power because relief circuits control that, but you do get your closer to rated flow gpm. If you like to use multiple cylinders fast you need the flow up.

 

[c304]

Well, got my first bit of serious seat time in today. Beautiful weather. Used the loader and backhoe to pick up some large items like appliances and rugs and waste cement and drop them in the dumpster we're renting. Good stuff.

Then my wife said "dig out that stump in the side yard that the kids keep tripping on". Cool!

Everything going great, played around with different engine RPM. It did only marginally better at higher RPM, but it was too fast for my skill level, so I left it at low. Got some good digging going on until I swing the boom aaaaaall the way to the right to dump out a load of dirt. Now it won't swing back. It's like the control lever does nothing. Don't hear anything happening. If I hop out and manually push REALLY hard, I can move the boom a few degrees to the left. Back in the seat I can swing it left until it hits the limit, but I can't swing back.

So how much trouble am I in? All the other hydraulic functions work, the stabilizers, loader, bucket curl, etc..

 

[Hersheyfarm]

My m59 had done that before. But working the controls brought it back. Did you try aggressively moving stick back and forth with idle up? Could be a sticking relief valve. Also look at your hydraulic quick connect for backhoe to make sure they are seated good. With engine off, let all pressure off by moving sticks and lowering boom/bucket. Then push on all 3 quick connects. The try it out.

 

[Fallon]

Worst case scenario is a bad valve in the stack. Several hundred bucks for a new valve in the stack & a fair bit of work fiddling (labor) with plumbing to get it replaced. I'd suspect linkage issues between the operator & valve first.

 

[rScotty]

Well, got my first bit of serious seat time in today. Beautiful weather. Used the loader and backhoe to pick up some large items like appliances and rugs and waste cement and drop them in the dumpster we're renting. Good stuff.

Then my wife said "dig out that stump in the side yard that the kids keep tripping on". Cool!

Everything going great, played around with different engine RPM. It did only marginally better at higher RPM, but it was too fast for my skill level, so I left it at low. Got some good digging going on until I swing the boom aaaaaall the way to the right to dump out a load of dirt. Now it won't swing back. It's like the control lever does nothing. Don't hear anything happening. If I hop out and manually push REALLY hard, I can move the boom a few degrees to the left. Back in the seat I can swing it left until it hits the limit, but I can't swing back.

So how much trouble am I in? All the other hydraulic functions work, the stabilizers, loader, bucket curl, etc..

Don't panic! That's a known glitch with the M59. I've had it and several other owners have too.
Check this thread:
http://www.tractorbynet.com/forums/...swings-right-but-not.html?highlight=M59+swing

 

[c304]

!

Well shoot, when the sun comes up tomorrow I'll give it a try. Drop the right stabilizer, lift the left, push the boom to the left until gravity takes over, then rock the control back and forth while upping the RPM's and pray to the spirits of the hydraulic fluids?

 

[rScotty]

!

Well shoot, when the sun comes up tomorrow I'll give it a try. Drop the right stabilizer, lift the left, push the boom to the left until gravity takes over, then rock the control back and forth while upping the RPM's and pray to the spirits of the hydraulic fluids?

That's sounds right. I'll expand on my experience in the hopes it will help.

When it happened to my M59 back in 2012, it didn't come about because of a hard swing, in fact I was washing, cleaning, and lubing the zerks at the time. The symptom was that it would power-swing to the right, but would not power-swing back to the left. I could move it to the left by getting off the tractor and pushing on the backhoe bucket - but only if I simultaneously held the swing valve open as though it were being powered to the left. It wasn't easy to push, but I could swing it all the way to the left that way and then power it back to the right

Swinging it that way got tiring, so what I did is put down the right stabilizer all the way. That tilted the tractor enough so that I could power-swing to the right and then let gravity swing the backhoe to the left. At the time I don't claim to that I knew what I was doing or how it might help. I was just sitting there powering one way and letting gravity swing it the other in the hope that inspiration would strike - when it suddenly started working.

Now 6 years later and right at 1000 hours the backhoe hasn't had a problem since. It is works smoothly and is remarkably powerful. I used it today moving 1000 lb boulders to build a fishing hole in our creek.

Several M59/L45 owners have had similar malfunctions over the years and now we have more information. Losing one or another of the backhoe functions is a known problem with the larger Kubota TLBs, and one that Kubota has never commented about. The common finding among owners who did some wrench work was discovering rubber fragments in one or more of the valve bodies. Apparently it can be in the control valves, relief valves, and check valves. I don't know if the source has ever been established...and likewise I've
not heard of anyone finding rubber bits in the filter.

The hydraulic section of the shop manual is sufficiently detailed so that a person having a problem with the backhoe controls should be able to diagnose the most likely valve(s) from the diagrams.

I'm assuming that was what happened to mine was that it also had rubber bits stuck in the swing valve system somewhere, and that my doing that gravity swing somehow pushed fluid through the system and flushed the valve. If that is correct, then it also makes sense that gently bouncing the boom while gravity did the swinging would create pressure spikes that might help loosen debris.
I'm not sure that running the motor at high RPM makes a difference. In fact, high rpm might damp the pressure spikes.
Mine was idling when it suddenly started to work, although I had tried high rpm not long before.

Another point in favor of the "rubber bits & flushing" theory is when gravity swings the boom it seems to me that the hydraulic fluid is forced in an opposite direction from normal flow. If so, it would be forced backwards through the open swing valve. and that reverse flow in combination with the pressure spikes by bouncing the boom would create a powerful back-flushing flow.

I do wish that when a lot of owners report the same problem that Kubota would work on the problem and communicate with their owners instead of just forgetting about owners who are past the warranty. Done properly, ongoing communication with owners could be a powerful sales tool. But it does require a major philosophical shift and that is apparently difficult for companies to do today.
So far, TBN is your best source for information.

Good luck c304,
rScotty

 

[c304]

Ok, I'm working alone, so can't get to the controls and push on the boom far enough out to get leverage. I'll give it another try when the kids get home.