Mt 240he hydro cavitation?

   / Mt 240he hydro cavitation? #12  
tractor was at the dealer for a week, picked it up today. They were able to reproduce the noise several times, but not locate the cause as it only lasts a few seconds and usually just the initial start of the day, or after sitting several hours, enough to cool down completely. It hasn't changed over the last year, but we'll see if it gets worse, and if we can identify the sound location here, and get it back in before the warranty is up in another year. The sound originates from the front, under the hood, so it isn't the HST, but the turbo, hydro and steering pumps are up there. LS corporate says it may be a "relief valve sticking" but the techs were unaware of a relief valve up front anywhere. Wish there was something more definitive to report rather than a wasted week.
 
   / Mt 240he hydro cavitation? #13  
Remote valve is not in a detent position?
Is the 3pt lift all the way up? maybe try moving it down an inch.
If you engage the PTO does it change pitch or stop it immediately?
1) My remotes do not have a detent position, they are return to center. I had them added maybe 8 months after I got the tractor. The noise happened before I had remotes and continues without change with the remotes.

2) Usually, I have all hydraulic pressure relieved when I shut down, start, warm up, raise the 3pt all the way up, and the FEL high enough for transit. I'll try lowering the 3pt when the sound happens.

3) Haven't tried that, usually like to let it warm up more before engaging the PTO, but will give it a shot.

Noise really only happens when I initially start moving.
 
   / Mt 240he hydro cavitation? #14  
tractor was at the dealer for a week, picked it up today. They were able to reproduce the noise several times, but not locate the cause as it only lasts a few seconds and usually just the initial start of the day, or after sitting several hours, enough to cool down completely. It hasn't changed over the last year, but we'll see if it gets worse, and if we can identify the sound location here, and get it back in before the warranty is up in another year. The sound originates from the front, under the hood, so it isn't the HST, but the turbo, hydro and steering pumps are up there. LS corporate says it may be a "relief valve sticking" but the techs were unaware of a relief valve up front anywhere. Wish there was something more definitive to report rather than a wasted week.
From what I remember mine did the exact same thing. Sometimes if it didn't make the noise right away it would as soon as you touched a hydro pedal and only after sitting for a day.

Your power steering pump supplies oil to the steering, hydrostatic pump, and oil cooler. Within the steering circuit your steering valve has a relief built into it so if LS is thinking of a relief that's the only one I know of besides the hydro relief under your feet. Maybe get a stethoscope and have someone start it why you listen to different lines and hoses.

Good luck in your mystery.
 
   / Mt 240he hydro cavitation?
  • Thread Starter
#15  
First thing if you have a screw on hst filter make sure it hasn't come loose, if the filter is right the filter screen may be stopping up other than those filters it's possible fluid itself is breaking down. I had issues with my hst where the filters were the cause and also issues trying fluids that was suppose to meet specs but quickly started breaking down because it couldn't disperse / get rid of moisture in the fluid, and that's where most cavitation is caused by water / moisture in the fluid / oil and air also. Only two fluids I use now Mahindra universal tractor hydraulic fluid and Sinopec universal tractor brake hydraulic fluid both of these fluids work great on my emax25 without breaking down before time to change.

Seriously doubt it is a fluid breakdown or filter issue. Still on it's original fill and filter was changed according to LS 50 hr maintenance. Filter is original LS and installed properly. Is definitely an aeriation issue. The oil is very foamy when the noise starts and you can hear the oil being drawn to the hydraulic and steering pumps on a cold start. Definitely a loss of prime issue. I need to pressurize the suction side and see if it will leak.
 
   / Mt 240he hydro cavitation?
  • Thread Starter
#16  
tractor was at the dealer for a week, picked it up today. They were able to reproduce the noise several times, but not locate the cause as it only lasts a few seconds and usually just the initial start of the day, or after sitting several hours, enough to cool down completely. It hasn't changed over the last year, but we'll see if it gets worse, and if we can identify the sound location here, and get it back in before the warranty is up in another year. The sound originates from the front, under the hood, so it isn't the HST, but the turbo, hydro and steering pumps are up there. LS corporate says it may be a "relief valve sticking" but the techs were unaware of a relief valve up front anywhere. Wish there was something more definitive to report rather than a wasted week.


Thanks for the update. At least you have a paper trail that the dealer duplicated the problem and could not repair it. If it gets much worse or damage happens you will have a much better chance of getting a good will repair done on LS's dime if it fails out of warranty. Of course, a lot of polite beaching will be involved most likely. 😁
 
   / Mt 240he hydro cavitation?
  • Thread Starter
#17  
had to clean my hst screen filter twice after the first fifty hour service, yep that foamy fluid is a indication something going on. Mine had a good bit of break in material. last week I did another fluids change 1180 hours and the screen was very clean just a few specks but got cleaned anyway. I wonder if the dealership actually cleaned the hst screen on mine on the fifty hour service.


Where is the screen on an MT240HE?
 
   / Mt 240he hydro cavitation? #19  
Is the 3pt lift all the way up? maybe try moving it down an inch.
If you engage the PTO does it change pitch or stop it immediately?
no change moving the 3pt down or engaging the PTO.
 
   / Mt 240he hydro cavitation? #20  
I haven't replaced the hydro filter (driver side) on mine yet since the manual doesn't call for it until 300 hrs but I have been topping the hydraulic fluid off with the same Shell Rotella HD Tractor Transmission & Hydraulic Fluid.

EDIT: Well crap! I opened the manual and looked again to confirm the hydro filter and I was looking at the Mech drive chart and not the HST drive chart. I ne
 
 
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