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Dewatering hydraulic fluid

danielm ยท 2008-01-03 21:30

I found 15 gallons of milky hyd fluid in my backhoe. Changed the filters and fluid but I suspect the hoses and cylinders will hold a fair amount that I cannot get out. My plan is to run it and change the fluid again. I hate to waste 30 gallons of hydraulic fluid if there's a way to dry it. Hydralic fluid seems to hold water in suspension. It does not settle out like in other oils. Can anyone suggest a way I might be able to dewater this oil? Can I put it in a vacuum chanber and boil the moisture off ? Ideas?

Replies11
  1. #1rino14942008-01-04 06:49

    Why even waste your time trying. Just drain the fluid and leave the plug out. Disconnect a hyd. line and hook up a air hose to it and blow the fluid back through the tank. You won't get it all out, but you will get most of it. It is best to do this to every line.

  2. #2danielm2008-01-04 09:54

    Just under $8 gal is one reason. Then even if its not good to reuse I can burn it in a waste oil htr. Air won't get it out of the 11 cylinders and they're assoc hoses. I'm going to try to heat 5-10 gals at a time in a vacuum. We'll see if I can boil if off. Then I'll filter it and check the ph to make sure its not become acidic.

  3. #3ror76a2008-01-04 10:06

    Good luck. Sounds like at this point anything is worth a try, even if you ruin the oil, you still have not lost anything. I had water in a transmission once and the oil fliter removed it, it took a couple of filters to get it all out, but it would be worth a try. I had one of my old excavators get water in the hyd oil, took a few filter changes and about 3 oil changes to get it out. That was a few years ago and oil was less, but it was still an expensive experiance at about 120 gal per change. The I have the old oil in barrels and was thinking maybe it would seperate, no luck so far. I should check it now that everything is frozen, maybe the water will freeze and seperate :beatsme.

  4. #4Ross2008-01-04 10:59

    Water in the Hydraulic oil? Ide be trying to find out were it came from. Ross

  5. #5danielm2008-01-04 11:43

    I just picked this machine up where it sat for a year under the edge of a roof. I assume the run off found its way thru a boot. I'm checking into this. No moisture was found in the crankcase oil.

  6. #6rino14942008-01-04 16:37

    $8 gallon is only $240. Yes, air won't get out all of the oil, but neither is draining the tank. You have to disconnect each hose and blow back through the tank. This is the best way to get most of the watered hyd oil out. Buy new oil and a filter and you should be golden. I've done this on 2 machines and the oil in the sight glass is crystal clear.

  7. #7Underdog2008-01-04 18:31

    This is a case of a "penny wise and a pound foolish" Discard the oil in the waste oil drum. Trust me I've learned this lesson well. Go ahead and price hydraulic parts today. You will be much further ahead in time, money, and aggravation.

  8. #8stumper1202008-01-04 19:21

    heavy equiptment aint cheap i agree with underdog. like i tell everyone grease and oil are cheap parts and labor arent let alone down time. when the moisture seizes up a spool valve or a relief ball cause its rusting things up. $250 in oil is a cheap fix. or better yet frag a hydo pump and send metal through the system. just think of it as buying waste. oil cut it with some clean waste oil and burn it. i burn 60 gallons of diesel a day at $3.54 a gallon .:usa

  9. #9celticcrusader2008-01-04 20:20

    how old is the oil[ hours] ? hyd oil is not good forever you know. do you do oil scan? if it is new oil and like someone else said about pulling hoses and drianing cyls. you can put oil in a drum weld in a bottom drain and leave it sit in drum . oil & water will seperate [oil floats on water] it may take a few days or more . BUT if its OLD OIL why waste your time ?

  10. #10danielm2008-01-05 17:43

    No plans to re-use it in the hyd system. I just hate to throw out 30 gals of oil that I could possible use in a waste oil htr. I've rigged up a flash evaporator. Pressurized oil is heated then fed thru a small orifice where water will boil off. So far, nothing but time invested, lots learned.

  11. #11jughead2008-01-10 19:17

    hydraulic dewatering if it is an emulstion my home made boiler will burn it with ease