Case/David Brown 990 selectamatic

subsoil

New User
Hello, I have a case 990 selectamatic. I have been restoring it. Thankfully it is running and functioning well. When I began working on it there was water in the hyd - system , as it had been setting out in the elements ( uncovered ) for years. I changed the hyd fluid and filter. Then ran it occasionally for a few minutes , while I continued to work on it. Of course the fluid picked up some of the water that remained throughout the internal housing. I drained and changed the hyd oil and filter a second time. I expected to have some water still present in the case, as there are many nooks and cranys for it to dam up in. The oil is now once again milky white. I need to change fluid and filter again. I have drained some of the oil to see if the water would settle out out of the oil but it does not ( after 4/5 days of sitting ).
I have read other posts that suggested using diesel fuel to flush the oil and water out. I wanted to get some opinions, ( pros - cons ) , before doing this. I would appreciate some advice from folks that have experience in dealing with this situation, before I change the fluid and filter yet again. Thank You, Steve
 

You're only going to be able to get so much water out. The transmission is vented and the oil will pick up atmospheric moisture as it gets warm and cools. And I have never seen a gear shift boot that didn't leak. If you can keep it under cover, it helps. If you can't, you just get used to doing an oil change spring and fall.

As far as getting the water out of the oil, I've tried letting is sit for months, heating it to boil it out and filtering it through various mediums. Nothing works. If you could find one of those oil reclaimer units for cheap that might work. I've seen them in the $500-800 range, but not very often.
 
Cheap hytran isn't much more expensive than diesel. Diesel has virtually no lubricating properties. Diesel has no water collecting abilities. You are risking all sorts of parts by using it to flush.


Use the cheap yellow bucket oil and change it every few months. eventually it will quit getting milky.

on a badly contaminated system, I have changed it 4 times before I was happy.
 
Thanks to both You and Bret. I was concerned about the lack of lubricity if using diesel to flush with. Since the last time I changed the hyd fluid I have had the tractor on some steep grades, in all positions. I suppose that moved water out of casting traps that the water didn't drain out of when the tractor was level. Yes I'll use the cheap TCS oil until I get it cleaned out. Then change to a better grade. Thanks, Steve
 
You can get a little (very little) water out of oil by freezing it. I put a few quarts of automatic transmission fluid in my system when I had the same issues. I thought it helped. But because system is vented it will get water in it. If I am going to park mine for a bit I crack the lowest drain plug. I think this helps but don't forget to tighten it!!!!
 
I used an outdoor turkey cooker and five gallon pot. Heated milky oil up to 214* all water evaporated out.
 

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