JD 4440 water in hydraulic fluid

   / JD 4440 water in hydraulic fluid #11  
Hyd oil cooler & AC condenser are integrated but not connected & mounted in front of radiator with no hoses connecting cooling & hyd system.
 
   / JD 4440 water in hydraulic fluid
  • Thread Starter
#12  
Sure does sound like water. No clue on how or if anti-freeze could get in hydraulic system. Most common would be oil to water heat exchanger but per above post your tractor does not have that style of heat exchanger - radiator.

Do you use this for field work or more of chore tractor? If chore tractor is it possible that you are just getting it warm enough to create condensation but not hot enough to cook it out?
Tractor is used for field work, but since the last hydraulic oil change it has really only been used on the disc bine. When running the disc bine tractor always runs cool. Needle on temp gauge barely makes it to the green mark. Maybe it isn't getting hot enough to burn off the condensation? Or maybe the vent cap is blocked? Next spring I'll be breaking some land with it, I'll keep an eye on it then.
 
   / JD 4440 water in hydraulic fluid
  • Thread Starter
#13  
Hyd oil cooler & AC condenser are integrated but not connected & mounted in front of radiator with no hoses connecting cooling & hyd system.
Right, that makes sense. Hydraulic oil cooler is oil to air exchanger, correct?
 
   / JD 4440 water in hydraulic fluid #14  
Yes that's correct
 
   / JD 4440 water in hydraulic fluid #15  
Albert
I hope is something as simple as plugged vent and or a little condensation.
 
   / JD 4440 water in hydraulic fluid #16  
A while back I hooked up to my cultivator. Turned out one of the vertical mounted cylinders had a seal fail, and taken on water. When I cycled the cylinders I contaminated the tractor hydraulic fluid with water.

I initially drained the fluid and refilled with new fluid. I drove the tractor for 20 min, and drained and refilled again. Fluid looked good at that point.

I used the tractor to cut hay, noticed the fluid had gone cloudy again, but less cloudy then the initial contamination. I drained and refilled with new fluid again.

Used the tractor to cultivate and the fluid is now cloudy like the time before.

A couple of questions. Do I just need to change the fluid a time or two more? Is it possible there could be coolant getting into the hydraulic fluid through a cooler or something?

I have also been flushing contaminated fluid out of implements before I use them
This might be helpful:

Hydraulic oil will absorb oil until it is saturated, then free water will accumulate below the oil. If you see cloudy oil but no free water then it has water but is not yet saturated.

For my M6800 I attached short hoses to a hydraulic filter adapter and two fittings on hose end that plug into a back of tractor remote. By plugging it into a rear of tractor remote and operating the tractor remote it acts like a removeable kidney filter to clean up and remove dirt. A back pressure gauge installed in the gauge port of the adapter monitors the filter pressure and lets me know when to change the element. For a 4440 you might use low RPM and a slow setting on the remote turtle/rabbit knob. Select a filter adapter based on a inexpensive filter element.

Some filter manufacturers make a water absorbent filter for hydraulic systems that would also fit this housing. This uses a desiccant to absorb the water.

You know that a vacuum pump is used to remove water molecules from an AC system. As the pressure is lowered the water will boil at room temperature. I have a good vacuum pump, and purchased a $50 Chinese "vacuum chamber" on ebay marketed for evacuating air bubbles from silicone mold casting. It looks like a cooking stock pot with a thick clear plastic lid and latches.

I drop a hose from the remote of my bobcat into the pot and fill it 2/3 full of oil, then put on the cover, turn on the pump, and watch the water boil off. It is literally pretty cool because the water boiling absorbs heat so the bottom of the pot gets cold. I pour the dehydrated oil into a clean bucket and do the next batch. This lets me dehydrate oil without buying $150 buckets of new oil.

I have not sent samples to a lab to see before and after results.


Kind of nutty, but I think it works.

Jim, retired industrial maintenance specialist
 
   / JD 4440 water in hydraulic fluid #17  
Hydraulic oil will absorb oil until it is saturated

Meant that, or a typo?
 
 
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