M59 hydraulics got slow and weak.

[BandDcabinet]

I've dug for hours with the M59 BH. I'm really confused. I never change the auto-throttle or Hst mode when using the BH. I don't dig in neutral... I use the creep often. Set the hand throttle and dig away. Only time the auto throttle ever engages might be when using the creep if the hand throttle is set to a low rpm. I'm putting in a french drain system tomorrow I'll try all of the modes I can think of and report back. I also have Kubota shop manual for hydraulics. I'll take a look to see if they have any comments.

Never any overheating, summer or winter. Approaching 400 hours mostly digging.

 

[Hersheyfarm]

I've dug for hours with the M59 BH. I'm really confused. I never change the auto-throttle or Hst mode when using the BH. I don't dig in neutral... I use the creep often. Set the hand throttle and dig away. Only time the auto throttle ever engages might be when using the creep if the hand throttle is set to a low rpm. I'm putting in a french drain system tomorrow I'll try all of the modes I can think of and report back. I also have Kubota shop manual for hydraulics. I'll take a look to see if they have any comments.

Never any overheating, summer or winter. Approaching 400 hours mostly digging.

The auto throttle is no issue for restricting hydro fluid, just the the stall guard. Maybe wile digging halfway thru switch the stall guard on or aff and see if you see any difference. I seem to have more speed and power with it off, especially the bucket curling.

 

[rScotty]

I'm realizing that unlike most machinery that I own, I don't have a real clear mental picture of the relationships of the HST, the auto-throttle, stall guard, and which pumps and valves do what to which circuits. Sounds like a nice self-study for the winter. '

At part throttle digging none of the above seems to make a difference - or at least not enough of a difference that I've ever noticed it. Here on our place our ground is such that I cannot imagine running at full RPM. For one thing, that much power would sure make a rough ride in the BH seat. Even at part throttle the BH tosses the tractor around. If that happened every time I hit a hard spot in the ground - which is almost every bucket full - it would make for a long afternoon.
The creep function sure is handy for repositioning the tractor while digging.
rScotty

 

[Hersheyfarm]

I guess I have a lemon. It goes to the shop in morning. It's gotten so slow and weak it's difficult to dig with. Will post what happens. It has 75 hours since I picked it up from the dealer.

 

[Texas Fella]

Maybe this will help clear some things up:

1. Auto Throttle simply links the HST foot pedal to the fuel rack (controlling engine RPM) via a mechanical connection.

2. Stall Gaurd works with the engine RPM and the HST transmission. When the transmission is not in nuetral (ie the HST pedal is pressed forwards or backwards, nothing to do with the l/m/h), the ECU reads the engine rpm and if they drop below a certian point (due to load), the ECU sends a signal to the F or R solenoid (that contrals the HST swash plate, ie, F or R movement) than begins returning the swash plate back to the nuetral position (basically "backing off" on the pedal done electrically, not mechanically). Once the RPMs recover to a pre-set point, the ECu gives the operator (foot pedal) back control of the HST.

3. The process of the ECU kicking into "stall gaurd" mode does not, in and of itself, create any additional heat or restriction. It is effectively the same thing and the operater driving into a pile of dirt, hearing the engine drop in RPM, and "letting off" the pedal some.

4. Stall Gaurd will have not effect on any other hydraulic circuit (loader, 3 point, or BH) under any circumstance. Stall Gaurd only effects the HST.


I hope this helps. Keep in mind, this is a basic explination of what is going on, so if you too are knowledgable in Kubota HSTs, please do not pick it apart too much.

 

[Hersheyfarm]

Maybe this will help clear some things up:

1. Auto Throttle simply links the HST foot pedal to the fuel rack (controlling engine RPM) via a mechanical connection.

2. Stall Gaurd works with the engine RPM and the HST transmission. When the transmission is not in nuetral (ie the HST pedal is pressed forwards or backwards, nothing to do with the l/m/h), the ECU reads the engine rpm and if they drop below a certian point (due to load), the ECU sends a signal to the F or R solenoid (that contrals the HST swash plate, ie, F or R movement) than begins returning the swash plate back to the nuetral position (basically "backing off" on the pedal done electrically, not mechanically). Once the RPMs recover to a pre-set point, the ECu gives the operator (foot pedal) back control of the HST.

3. The process of the ECU kicking into "stall gaurd" mode does not, in and of itself, create any additional heat or restriction. It is effectively the same thing and the operater driving into a pile of dirt, hearing the engine drop in RPM, and "letting off" the pedal some.

4. Stall Gaurd will have not effect on any other hydraulic circuit (loader, 3 point, or BH) under any circumstance. Stall Gaurd only effects the HST.

I hope this helps. Keep in mind, this is a basic explination of what is going on, so if you too are knowledgable in Kubota HSTs, please do not pick it apart too much.

Thanks. Now if you could only explain why my machine is going on its 3rd set of pumps in 212 hr...lol

 

[rScotty]

Thanks. Now if you could only explain why my machine is going on its 3rd set of pumps in 212 hr...lol

Third set! Well, I don't know how it works in Ky, but in Colorado there is a limit on how many times a dealer gets to try to fix something before the "lemon law" more or less automatically kicks in to protect the consumer. Ky probably has something similar. Here, it's a law with some serious teeth in it. Probably wouldn't hurt to get up to date on your rights.
good luck, rScotty
- whose M59 is working along just fine with about the same hours as yours.

 

[BandDcabinet]

Hi Scotty. Some 230 odd hours on mine. Don't recall the exact and not near it to check. No issues. 50% of time using BH. 40% loader/forks/pushing snow. 10% chipper/flail work. Work is generally at 70 to 80% of tractors capability.

Tires are showing "dry" cracks. No other issues. I would say most work is in M at avg. approx 3/4 throttle.

Run SUDT and now SUDT2. Filters changed at approx 100. Oil just recently.

Share Skidsteer attachments with other farm machines running other Hyd fluids.

Wish I had an answer.

 

[Hersheyfarm]

I do operate the backhoe at 2700rpms. Kubota said that it helps keep heat down when digging for hours, not mention maximum performance.

 

[Hersheyfarm]

Third set! Well, I don't know how it works in Ky, but in Colorado there is a limit on how many times a dealer gets to try to fix something before the "lemon law" more or less automatically kicks in to protect the consumer. Ky probably has something similar. Here, it's a law with some serious teeth in it. Probably wouldn't hurt to get up to date on your rights.
good luck, rScotty
- whose M59 is working along just fine with about the same hours as yours.

Our lemon laws exclude equipment and is for cars/trucks basically.