I just replaced some old hydraulic hoses on my early 580K farm hoe, and I'd like to do a total change out of the hydraulic fluid, including opening the clean out hole in the reservoir to get all old junk that may be present. I recently found that Case recommended 10W30 API CC motor oil as the hydraulic fluid of choice when the unit was new (can see at www.case580kbackhoe.com ). Now Case wants me to use HyTrans. I see on here a number of folks recommend AW32. I've found an old, still sealed 55 gal drum of Citgo SAE10 motor oil with API CC,CD/SF,SE for $100. I've read the other posts on this subject. Those of you who think AW32 is just fine for my hydraulics, what do you think of this SAE10? Also, I can't think of a reason a sealed drum of oil would have any problems - correct, or short sighted?
There's a bunch of Case experts on here, but I'm not one of them. Until they come along... I wouldn't hesitate to use that oil as originally recommended. Presumably the oil is hydraulics only, no brakes or clutches, so the hytran is a bit of overkill. Hydraulic oil would be fine too. A sealed drum can absorb water if any air gets past the seals, so be careful that the oil looks clear like new motor oil, and don't pour the dregs into your tank. Also consider the options for getting the most old oil out with the change, there's 10-15 gallons in the cylinders and plumbing.
What is the best way to remove it from the cylinders. Have all rams retracted as far as possible? Or?
The BEST way involves removing lines. An easier way to change more than the oil in the reservoir is to shut it off with the cylinders extended, drain the oil and remove the filter (or the return) and leave an empty bucket under the drain and filter housing, lower the cylinders that will lower under gravity. That will get about half the remaining oil. Leave the cylinders retracted that won't retract under gravity, or get creative to retract them to get a little more.
what about draining the tank . then put in just enuff 5 gal fresh est. . cycle every cylinder in one direction .. i/e put stablizers down only lift loader up only, swing from far left to right only etc this would push out old oil from each cyl and fill them with the fresh onto the other side of gland . then drain the remnants in the tank . it may not be 100% but doable or do same with even less fluid and do the drain tank n fill short tank method one cyl at a time because by the time you flush 3 circuts the old oil gets back into the fresh oil in tank and its not fresh anymore to run back out to next cyl flushing sound crazy . you can never get it all out with out some major opening . if you can replace 75% whooopie if one pops a hose which is a worse oil spill hydro fluid or motor oil isn't motor oil nastier on the enviro than hydro/ mineral oil ? that gravity idea sound kool to do