M59 hydraulics got slow and weak.

[Hersheyfarm]

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]

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]

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]

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]

General question?

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

 

[rScotty]

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]

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]

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]

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]

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