Seperating water from hydraulic fluid

[woodbowl]

I just drained the hydraulic fluid from a backhoe and it is quite milky with water to say the least. Since I am cheep thrifty I always store old oil in the barn for a couple of years and let it settle out. I pour it off the top and it looks good as new.

In this case I am in a hurry and didn't really want to buy 10 gallons of new oil. I googled a few key words and found forums using tolit paper filters and chemicals. I did a little experiment and heated some in a can untill all the water steamed out and it was clear.

I don't plan to go to a lot of trouble on this, but it bugs me that people throw away emulsified oil. I know you can wait on it to seperate, but I think there is a quicker way. I don't plan to build an evaporator, but I have thought about setting up a drip system at the peak of the tin bar and let the sun work the moisture out then catching it in a bucket off the eave. 

[Magicman]

I've wondered that same thing.  Man, I hate to drain 5 gallons of milky hydraulic fluid and then use it to ignite brush piles.

Heating and boiling the water out would be risky, because that stuff will really burn.

[clif]

Ah, another reason to live in Alaska just set it outside in the winter!

[red oaks lumber]

oil is to cheap to risk wrecking something.change the filters more often or use differant brand

[Whitman]

If you have a large sturty contaner ,you can draw a vaccum on the mix. the water will come off as steam . the reverse of a pressercooker.  it will help if it is warmed to150f or more

[footer]

You could always buy one of these. You can get into an entry level one for a couple grand.
http://www.fischer-robertson.com/como_oil_recycling.htm

We did this with a bunch of Hydraulic oil at a place I used to work.
We set up a few 55 gal drums to seperate "most" of the water. We wleded some legs on the drum so the drum sat a couple feet off the floor in a virtical position. Welded a fitting in the bottom and screwed a Ball Valve in it. Put the Oil/Water in the drum. Get a Barrel Heater from someone like WW Grainger. Put heater around lower 1/3 section of the barrel and let it sit for a couple weeks. Drain out the water from the bottom.
We would then pump this into another barrel and run the recylcler filter system on this for a couple days.
With out the Recycler, you will probably get 99% of the water out, but there is a small % that wont settle out.

[sdunston]

Tractor sells a filter that is used for diesel but on light oils also, I was going to make a set-up but have not had time latley, but hyd oil @ over 10 bucks a gallon its time
Sam

[Dangerous_Dan]

Woodbowl-
You need a centrifuge.
I built a small one to clean WVO when I was running my homemade 50kw Veggie gen setup. It was the only way to get the oil clean enough to not plug the fuel filters every few hours.

DD

[Gary_C]

These equipment manufacturers have two schools of thought about water in hydraulic systems.

One belief by the people at CaseIH is that all hydraulic oil should have additives so it will absorb water in the oil. Their reasoning is so the water is held in the oil and doesn't precipitate out the other additives which will plug the filters. Plus free water in the hydraulic system will rust steel parts and cause problems and it will freeze in cold weather.

The guys at John Deere have the opposite viewpoint. They do not want any water absorbed in the hydraulic oil so no additives for that in their hydraulic oils. They prefer to allow water to collect in the bottom of reservoirs and hope it does not build up enough to get mixed in with the oil in the pumps.

So as far as I am concerned if any hydraulic oil shows signs of water, out it goes. I will not reclaim any to put back in the reservoir. I am not taking any chance on screwing up the additives or if the oil is saturated with absorbed water. Those hydraulic pumps and components cost way to much to replace and no amount of reclaimed oil can save anywhere near the cost of a pump and installation.

As much as I dislike the cost of that hydraulic oil, there is no way I am going to be an oil refiner too. 

[woodbowl]

I decided to change the filters and add more hyd oil to clean it up. Problem is there are no filters. For what ever reason someone has been running this backhoe without Hydraulic oil filters.    I just bought the machine. Knowing that the hydraulics move slow and the fluid is like pancake batter it was reasonable to think that an oil change would bring it back into operation, and may still.

I have no idea how long it has ran without filters. I just hope the pumps are ok. The plan is to fill it with fluid and run it through a few cycles to mix it all together then drain it again. I suppose the correct thing to do is to install new filters. Immediate clogged filters comes to mind. I may not put them on. Go ahead and shoot me.

At any rate it seems that I will be going through quite a bit of hydraulic oil just to get things cleaned up. I'll be saving this oil for sure to seperate the water from it. I'm all for new oil in a running machine. If for nothing else, reclaimed oil that the water has been cleaned from would make a good cleaner for future water problems. I just checked my tractor hyd oil. Now how did that water get in there again, I just changed it a few years ago.

Woodbowl-
You need a centrifuge.
I built a small one to clean WVO when I was running my homemade 50kw Veggie gen setup. It was the only way to get the oil clean enough to not plug the fuel filters every few hours.

DD

OK Dan, you talked me into it. How did you build your machine?  I've got two 5 gallon buckets of contaminated hyd fluid ready to attach to the end of the bush  hog blades. How long does it take to sling the water to the bottem of the bucket? 

[submarinesailor]

This is one time when being "cheap/thrifty" could possibly cost you.  When you let oil set for long periods of time all the water does not drop out.   All of the oil not falling out has to do with everything from viscosity to water droplet size to ambient temperature.  This link “U.S. Navy Restores Mineral Hydraulic Oil on Submarines”:  http://www.machinerylubrication.com/Read/1056/mineral-hydraulic-oil  takes you to an article that explains some of this.  One illustration/comment in the article that I liked was that “due to viscosity, the water drop settling rate in the diesel fuel is about 20 times faster than that of the hydraulic oil for a water drop of the same size.”

This next link takes you to a video on what contamination can do to you equipment:  http://www.machinerylubrication.com/View/1806/hydraulic-contamination .
 
Here are several more articles about hydraulic systems and what you can do to maintain them:
http://www.machinerylubrication.com/Read/26929/pros-cons-hydraulic-filter
http://www.machinerylubrication.com/Read/25967/hydraulic-oil-lubrication-viscosity
http://www.machinerylubrication.com/Read/1396/hydraulic-equipment

Having worked a good number of hydraulic systems during my many years on the boats along with working in the oil sampling business  for a number of years, I STRONGLY recommend you take very good care of you hydraulic fluid.  Make Dang sure your filters are changed on a regular interval, based on usage and calendar year.  If you are making your living using big equipment, remember what the video said about cycle time and equipment failure.

One other point I would like to make.  If you have fluid in storage, keep it clean and TIGHTLY closed!  Just due to temperature changes around it, hydraulic fluid can become contaminated with water.  When this happens, algae can grow in your stored oil.  I know this for a fact because the team I was on in Kingsbay Submarine Base many years ago had to assist in the fixing of a contaminated boat.  Both the Main and Vital systems stopped working while they were on patrol.  They had to surface and wait for an ocean going tug to go get them and bring them into port.  What a mess!  All due to them not taking care of their stored oil.  When the main system needed oil they transferred contaminated oil from storage and the algae blocked all the filters and many of the electro-hydraulic control valves.

CLEAN YOUR SYSTEMS!

Bruce

[doctorb]

Submariner
Does that apply to systems that use low viscosity hydralic fluid (like automatic transmission fluid)?  It's used in wood splitters that routinely are not stored indoors.

Doctorb

[isawlogs]

 Woodbowl ,
 I wonder if putting the pails into a freezer if the water/oil would separate and only the water would freeze  ... if so you could use it to run through the backhoe till you have the system cleaned out , after that , put new oil in ...

[ely]

i dont mess with contaminated oil here. it is only 21 bucks for 5 gallons.

[submarinesailor]

Submariner
Does that apply to systems that use low viscosity hydralic fluid (like automatic transmission fluid)?  It's used in wood splitters that routinely are not stored indoors.Doctorb

Doc,

Based on what I have read, I would recommend you use an desiccant type air filter/breather on all your hydraulic equipment.  A quick Google search and I found this one:  http://www.des-case.com/.  Now, I don't know anything about this company, but it gives you a good illustration of a desiccant type tank air filter.  

Yes, they do cost more, but your oil and equipment could last longer.  Water is one of the biggest problems there is in oil systems, not just hydraulic systems. I wasn't kidding when I told you guys about that submarine.  I was recently involved in a problem at one of the very large Army bases that had about 260,000 gallons of #2 fuel that was NEVER treated.  When we finally got them to sample and test this oil, it was junk.  We sold it off for them at about 25% of what they paid for it.  It was too far gone to fix with clay filters and other treatment chemicals.  What a waste.  Good thing we jumped on them about sampling and testing.  They were getting ready to start feeding it to their backup/peak shaving generators - big ones.  About 2.3 MW each.  For once we got it right before there was any major damage.  

This is also why I like filling up my 250 SD diesel at the bigger truck stops.  They usually cycle though their oil more quickly giving it less of a chance of going bad.  Smaller mom and pop stations have a better chance of having water and other stuff in their oil, meaning fuel oil.

Any more questions, PLEASE let me know.  I hope worded all of this right

bruce

[woodbowl]

Thanks Bruce, that's a lot of good usefull information. Marcel, I ran across a site that mentioned freezing it. I'm gonna have to try a sample. Ely, I just bought 5 gallons this morning for about $34 bucks, cheapest in town.    I'm really excited about a slow drip down a piece of hot barn tin. It was 34° this morning here in north Fla. I guess I won't be doing it for a while.

[woodbowl]

Marcel I just took a container of milky hyd oil out of the freezer. The wife ain't happy about my experiments even though the container was in three walmart bags. So far it looks like a big slushy. I'll let it thaw and try to tell what's going on. Anybody know how the separation works?

I've drained the hyd oil and changed the filters on the backhoe twice now as well as clean the pick up screen and it seems to be working a bit better. According to the specs only a third of the oil will drain durring oil changes meaning that two thirds of the contaminated oil is still in the cylinders. This is starting to get a bit expensive.

Draining the cylinders is what I keep hearing about of how to purge the system. I tried it some, but I could see that it was going to be a big chore. I may could have left the loader, the hoe and the outriggers in the up position then gravity bleed it down after the oil was drained to purge a little more. Has anyone done this or am I unpriming the pump?

[sprucebunny]

Once the milky fluid is kind of frozen, strain out the ice crystals.

I had all the fluid out of my backhoe this summer and it sat there for 6 weeks. The pump did not un-prime. The pump on mine is at the front of the engine. I had replaced the main hyd. output line and was waiting for someone to weld the frame which is the hyd. reservoir.

[Banjo picker]

If you start bleeding the cylinders ...make sure everything is either in the down position or properly blocked...I know of a contractor that had a helper disconnect a hose while they were working on a dump truck several years ago, the bed was up and when the hose got loose enough the bed fell on him and killed him....the helper was his son.  Tim

[woodbowl]

Once the milky fluid is kind of frozen, strain out the ice crystals.

I can do that. It flows as slow as honey so I'll need to do it in the freezer. Da wife is really going to mad.

That's a tough one Tim. You just can't be too careful. I wouldn't want to undo anything in the up position. Using the control handle is what I had in mind.