M59 hydraulics got slow and weak.

Hersheyfarm · Jan 26, 2013

dsgsr said:
I have not experienced any Hydro whine in cold weather. I've been working the M59 in below 0 temps, I have John Deere Low visc hyguard for hydro oil. Since I changed to JD hyguard I've not had any problems in Cold or hot weather. I have yet to find a large enough Hypo syringe with hose to take a pic. of the oil for you folks.

David

That would be great. Tsc carrys large syringes. What I usedLincoln Industrial | Oil Suction Guns
Got it at autozone or orielys. I just put 3/8 pex on it as an extension

Hersheyfarm · Jan 26, 2013

The m59 flows 26gpm in a 12 gal sump. The case and Deere full size flow about 28gpm in 30gal capacities. The m59 moves the sump fluid twice a minute. That's some very busy fluid.http://www.machinerylubrication.com/Read/22923/tank-hydraulic-fluid

rScotty · Jan 27, 2013

mike69440 said:
As a 2005 L39 owner and the owner of a 1997 Komatsu PC75UU-2E 18,000 lb Excavator, I've been a troll following this thread. I'm a bit concerned about damaging the pumps on either of my machine as I am not in a position to afford to repair them if they fail, so I want to pick up any tips on operation or maintenance.
(SNIP)
So I'm wondering if something in the basic design hydraulic system of an M59 is allowing the oil to foam or cause other problems.
Although rated HP of the excavator is the same as an M59, the hydraulic reservoir hold 30 gallons of oil and the pumps put out almost 50% more volume and pressure than the M59, while not suffering The issues some M59 owners seem to have.

Well, maybe. I wonder the same thing too. Here's what I think: If it were a design flaw or an issue with the M59 model, then it seems like they should all do it. But we have to be careful complaining.....most of the M59 owners have no problems at all. Read the post from sdgsr right above this one. Reading back over the model history, owners that are not completely satisfied with the hydraulics are rare and breakdowns even rarer. And often things can be a harmless idiosyncrasy of a design rather than a fault.

On HerseyFarm's machine the hydraulic fluid gets too hot, and that seems the worst real problem we've come across. Though as far as I can remember his is the only one that does this. Is that right Hersey? And he does work the machine hard, although within spec. On mine, I get a cold weather hydraulic whine until it warms up, but nobody else gets that or at least hasn't reported it. And my whine doesn't change pitch when I use the backhoe, loader, or hydro when it is doing it. So who knows?

As for the foaming pictures, near as I can tell, the foaming is a new way to look at things and still too soon to know what that means...if anything. I wish some other people would check that on their machine and post a few pictures, though. Either foaming is common or it isn't, and either way I'd be interested to know more.
It may be that I simply caused the foaming by the way I took the sample. Taking a sample with a syringe means pulling the oil up by lowering the pressure via the syringe. The problem is that doing it that way is that reducing the pressure on a fluid is the most common way to cause foaming in any liquid. I might be seeing nothing more than a problem that I created. In fact, chances are good that's a large part of it. I need to figure out how to draw some oil samples in a different way.

Dsgr writes: "I have yet to find a large enough Hypo syringe with hose to take a pic. of the oil for you folks."
For anyone else interested, I got the hypo syringe from the horse vet, who also supplied a catheter tube that would fit the syringe and would withdraw the oil.

Yep,I agree.... the Komatsu does run about 50% higher pressure, but then Komatus also uses a different and unique type of load-sensing hydraulic system which is more related to JD's closed center hydraulic system. Both are a whole different animal than what Kubota uses. And Komatsu is lucky in that they can afford to spend their HP on higher hydraulic pressure since they don't have the same demands for travel that tractors do. The Kubota M59 uses a much simpler standard open center hydraulic system which should be -IMHO - much simpler, cheaper, and more rugged.
But I'm not knocking Komatsu. Those guys have an impressive machine, and their hydraulic scheme is downright ingenious. I'd love to have one.
rScotty

Hersheyfarm · Jan 27, 2013

As far as syringe causing the aeration, me catching the fluid in clear pitchers for filter change is the reason this was noticed. The chances the small negative pressure made by syringe is nothing compared to the negative pressure 26gpm creates. My temp readings on fluid is within kubotas specs, so aerated fluid plus temp is reason for loss of performance. Did I have bad pumps to begin with? Maybe. Can the design of the m59 be pushed to the limit of failure? Maybe. The loss of performance I experience is probably not noticeable pulling stumps or even culvert digging, but rather cycling in and out of a 10' deep sewer hole you notice it. When your trapped in thought digging ditches wondering what caused 2 pumps to fail , and your machine has been gone through and adjusted to spec and checked for flow and pressure under kubotas watchful supervision, you will tend to notice performance drops.

mike69440 · Jan 27, 2013

General question?

Does the L39/45/M59 Hydarulic system utilize an open or Closed Center?

rScotty · Jan 27, 2013

mike69440 said:
General question?

Does the L39/45/M59 Hydarulic system utilize an open or Closed Center?

It's an open center system. Very simple. When no work is being done, the flow is high and fluid simply races around the system from pump to sump and around again. Working pressure is developed when the operator moves a spool valve to divert some of the flow away from the main fluid path and over to a higher resistance path such as the line leading to a hydraulic cylinder.
rScotty

kuboman · Jan 27, 2013

mike69440 said:
General question?

Does the L39/45/M59 Hydarulic system utilize an open or Closed Center?

I think it is open center. One quick easy way to tell, does the loader or hoe operation speed up with rpm. If so then it will be open center.

dsgsr · Jan 27, 2013

I have a ? for those of you that own the M59. Does the engine lug down when operating the loader empty. I've noticed it when driving along and moving the loader lever, It seems to lug the engine down a lot. Dealer Service manager doesn't have a clue.

David

Hersheyfarm · Jan 27, 2013

dsgsr said:
I have a ? for those of you that own the M59. Does the engine lug down when operating the loader empty. I've noticed it when driving along and moving the loader lever, It seems to lug the engine down a lot. Dealer Service manager doesn't have a clue.

David

yea, that is normal. I think it the fact that you are moving 2 cylinders on one circuit and the wheels. your always parked when using backhoe. All my loaders acted this way.

dsgsr · Jan 28, 2013

My John Deere does not do this, Thats why I thought it was odd. There is no load other than the hydraulics themselves. Must be a Kubota thing.

David

mike69440 · Jan 28, 2013

rScotty said:
It's an open center system. Very simple. When no work is being done, the flow is high and fluid simply races around the system from pump to sump and around again. Working pressure is developed when the operator moves a spool valve to divert some of the flow away from the main fluid path and over to a higher resistance path such as the line leading to a hydraulic cylinder.
rScotty

I guess that is refered to a parallel/series open circuit. Principles of Hydraulics

Hersheyfarm · Jan 28, 2013

dsgsr said:
My John Deere does not do this, Thats why I thought it was odd. There is no load other than the hydraulics themselves. Must be a Kubota thing.

David

All the 310's I've ran, my 580L, my Massey 4345... Usually dumping bucket will lug the motor a little.

dsgsr · Jan 29, 2013

Hersheyfarm said:
All the 310's I've ran, my 580L, my Massey 4345... Usually dumping bucket will lug the motor a little.

This does not lug a little, it lugs the engine a lot, just lowering the loader while moving lugs it alot.

David

TBarD · Jan 30, 2013

My M59 has a bit of hydro whine/chatter for a minute or so when starting in cold weather, after which it is fine. I find that this is decreased when I engage the clutch. After the tests I ran I find that the machine when worked hard can warm up enough (after several hours) that one should monitor temperature and back off a bit if it is getting hot enough to endanger the hydraulic system components. However I have never seen any decrease in performance. I doubt if it would be practical to increase cooling significantly as the machine is just not that big, and the 12 gal of fluid is not that much for a 15-16 gpm machine. I suspect the air entrainment may be normal for open center systems (reservoir open to the air, ~10% air in solution), but have not been able to confirm. Bottom line - I am quite happy with the M59 and the compromises that went into its design.

TBarD · Jan 30, 2013

Correction, the total hydraulic pump capacity on the M59 is 26.7 gpm as Hersheyfarm noted; 16 gpm is just what the main hydraulic pump provides for backhoe/loader/aux (all at rated rpm). But we are running 26 gpm or so through a 12 gal reservoir. And yes it is open center.

Hersheyfarm · Jan 30, 2013

After I fed yesterday with my 4345 I drained some hydro fluid. It is very dark fluid because of the clutch I assume, but it was sparkly with air also. It was also still cool after running for a half hour. After it sat it was clear of sparkles. Maybe a hydraulic temp gauge is in my future. One more thing to stare at and obsess over.

Hersheyfarm · Jul 28, 2013

Been putting a lot of hours on this summer. The best way to describe my problem is sometimes the back boom feels 'heavy'. I changed the 3 hydro filters and there was a very fine black sludge on the magnets at top of filter. I would guess just metal residue from gears.

There was a very noticeable change in the response/speed of boom. It's just a little faster and a little more responsive for a wile.It's aggravating that its not consistent. I do watch the temp gauge of motor and at its hottest it never gets into the last 2 bars of the gauge, that's an hour or so of digging in mid 90 temps.

Sometimes I wonder if I'm just being **** on this, but there is a noticeable difference in the hydraulics.

TBarD · Jul 29, 2013

Hersheyfarm said:
Been putting a lot of hours on this summer. The best way to describe my problem is sometimes the back boom feels 'heavy'. I changed the 3 hydro filters and there was a very fine black sludge on the magnets at top of filter. I would guess just metal residue from gears.

There was a very noticeable change in the response/speed of boom. It's just a little faster and a little more responsive for a wile.It's aggravating that its not consistent. I do watch the temp gauge of motor and at its hottest it never gets into the last 2 bars of the gauge, that's an hour or so of digging in mid 90 temps.
.

The temp gauge on the console is monitoring the engine coolant temperature (at least I have always assumed so). The temperature of the hydraulic system is essentially independent and must be monitored separately. I use an IR gun which is very convenient to use and can monitor any visible point in the system.

rScotty · Jul 29, 2013

TBarD said:
The temp gauge on the console is monitoring the engine coolant temperature (at least I have always assumed so). The temperature of the hydraulic system is essentially independent and must be monitored separately. I use an IR gun which is very convenient to use and can monitor any visible point in the system.

Check me on this thought....It's sounding more and more like the M59's hydraulic cooling was originally designed a little too tightly....too close to max. There's not much reserve fluid...small sump, and so the fluid gets worked hard. The workshop manual advises a max temp at 140F on the fluid, but I think the measurements we've made show we're all pushing that. The system works for those of us in cooler climates running at 75% rpm, but TBarD's temp measurements show that the cooling is marginal. For Hershey's use in a hotter climate at full rpm the cooling of the hydraulic fluid might be the culprit. He's using the BH within specs, and by now there are enough posts so that we know he is seeing something the rest of us aren't. I admit it's a simple thought, but would explain a lot.

So can we make some simple changes to enhance the cooling? It might not take much. I don't see a downside.

Take a look at the hydraulic lines to the BH for example. I don't know how much cooling the original Kubota design engineer expected to realize from the surface of the hoses themselves, but it would be a substantial amount and easily calculated. Surely he did those calcs. But what happens when half or more of those hoses are covered with a heavy abrasive-resistant fabric? They are on my machine and given that the fabric is held on with zip ties it has the look of an add-on. Did the original designer anticipate that? That covering is nice for preventing damage (thanks, Kubota)..., but it has to interrupt the ability of the hose to rid itself of heat. In effect, those hoses are insulated. I wonder if it could be as simple as that?

Or take a look at the lines to the thumb. For half their length those thumb hoses are fabric covered, and for the other half of their length the same lines have a coil wire covering. I wonder if that makes a difference in how those hoses transfer heat to the air?

Of course we don't always use the thumb when running the BH, so chances are that system doesn't circulate enough that way to be the answer, but how about the main and boom cylinders themselves? There is lots of surface area there and anyone who has touched those cylinders while working knows that they get very hot. What about mounting some aluminum fins against the convenient part of those two big cylinders? Might be good to use some thermally conductive mastic there between fin and cylinder....., or maybe just a good fit would do it. The top surface of those big cylinders is very accessible, lots of heat transfer area, and some modest aluminum fins bedded in thermal conductive mastic and held on with some work clamps wouldn't be in the way of anything.

The heat gun would tell if it is effective.

Or how about the hoses themselves? Can something be wrapped around some of the BH hoses in such a way to help the hose surfaces themselves to transfer heat?

Maybe there are already some products like that on the market....Anyone know?
rScotty

TBarD · Jul 29, 2013

The M59 has a lot of power for a smaller/lighter machine; nice to have the power when you need it, but it does heat up if worked hard long enough.

I doubt if adding passive cooling would have a measurable effect, compared to just working the machine slightly less hard. In particular with the backhoe there should be much more heat loss from the big cylinders than from the hoses. When the machine heats up the whole bottom of the tractor (in the sump area) is the same temp as the oil, and this is a large surface area.

More active cooling could help, but would be hard to achieve. The best solution might just be to stop and have a beer every so often...