Assessing water in hydraulic oil

William1

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My un-expert feeling is... run an acceptable, cheap oil. Half a hour, working all components of the machine. Drain, refill and then run the tractor hard (six hours of work) to get it real hot. Water will 'boil off'. Every hour during this hard day, check the level, it should drop if there is still water in it. At the end of the day, drain and do it one more time.
I'd not run-flush it with anything but acceptable hydraulic fluid.
To those that might know, can a 'Mr. Funnel' be used to trap the water during a flush?
 
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North Idaho Wolfman

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First verify the at full capacity. Do a 100% drain and determine how much is left in cylinders etc. Fill with diesel fuel, run all hydraulics 1/2 hour and drain. Repeat with second fill 50-50 diesel and hydr oil. Then conplete by filling 100% hydraulic oil. Let the 50-50 mixture settle and any water in on the bottom.
That would be a great way to destroy a lot of the tractors systems!
Running diesel through the hydraulic system is an extremely BAD idea period!

Diesel in a HST would instantly destroy everything in it.
 
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D2Cat

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First verify the at full capacity. Do a 100% drain and determine how much is left in cylinders etc. Fill with diesel fuel, run all hydraulics 1/2 hour and drain. Repeat with second fill 50-50 diesel and hydr oil. Then conplete by filling 100% hydraulic oil. Let the 50-50 mixture settle and any water in on the bottom.
You put diesel in your hydraulic system and "....run all hydraulics 1/2 hour and drain". Then report how your HST operates!!! Advice no one should follow.

Late to the show, but man.......
 

Hman0217

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Kubota l3901 hst
Aug 12, 2021
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My un-expert feeling is... run an acceptable, cheap oil. Half a hour, working all components of the machine. Drain, refill and then run the tractor hard (six hours of work) to get it real hot. Water will 'boil off'. Every hour during this hard day, check the level, it should drop if there is still water in it. At the end of the day, drain and do it one more time.
I'd not run-flush it with anything but acceptable hydraulic fluid.
To those that might know, can a 'Mr. Funnel' be used to trap the water during a flush?
Thanks William

After reading this I had to do my own diligence because I didn't realize you COULD boil off the water. But it seems it's possible.

Will the fluid circulate if I just leave it running in a field or so I have to actually operate it continuously and keep moving the loader and backhoe?
 

William1

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BX25D
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Thanks William

After reading this I had to do my own diligence because I didn't realize you COULD boil off the water. But it seems it's possible.

Will the fluid circulate if I just leave it running in a field or so I have to actually operate it continuously and keep moving the loader and backhoe?
Just letting it idle will probably not heat up the fluid.
Drive it operate the FEL, move boulders, grade the drive way, dig a swimming pool. Operate every thing that is hydraulic to move the fluid and you want it hot. At least a few hours of hard work.
 

TheOldHokie

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Thanks William

After reading this I had to do my own diligence because I didn't realize you COULD boil off the water. But it seems it's possible.

Will the fluid circulate if I just leave it running in a field or so I have to actually operate it continuously and keep moving the loader and backhoe?
Do you know what the function of the hydraulic oil cooler is?

Dan
 

Mark_BX25D

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Bx25D
Jul 19, 2020
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To those that might know, can a 'Mr. Funnel' be used to trap the water during a flush?

Are you thinking of recycling the flush fluid to save money?

Mr. Funnel will separate out liquid water pretty well, but once that water is emulsified (milky oil), Mr. Funnel won't help at all.
 

MapleLeafFarmer

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in my experience (but not directly related to a 3901hst) because of nooks, crannies, low areas, filter media, etc..... can never drain 100% of fluid in one shot so triple rinse at minimum is probably going to be required.

a couple of times a year we get someone around here drown out an atv, utv, etc.... and often 3 complete fill / drain / filter replacements can get it correct but occasionally it takes more like 5+ drains and refills. Now these are not always hst machines just a contaminated oil observation from experience. I feel filters are a big culprit in holding water.
 
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