This gasoline powered (G159 engine) backhoe/loader had been sitting for a few years with vertical exhaust uncovered. I was able to rebuild and get her started after a good cleanout and reground valve seats, etc. Flushed the engine oil (twice) and it now runs great (with almost no oil burning). So... I pulled the hydraulic filter and the fluid was quite milky. Decided to drain and refill the frame/system (new filter, of course) and wanted to it it right so I started draining from the lowest point... the left-hand side of the frame had a drain plug so that's where I went. To my great surprise, the hydr oil coming out was completely clear. How is this even possible? How can part of the fluid be milky while the rest is unaffected? And... since Hydr fluid is expensive, how can I save the good stuff and dump te bad? Any help would be appreciated. Thanks
Maybe the oil is bypassing the filter because it is so full of contaminates. In regards to separating the contaminated oil from what appears to be clean oil, I wouldn't, it just isn't worth the risk of fouling up new oil.
No doubt you know more about these machines than I (almost anyone does) but it appears to be physically impossible to bypass the filter? The pump output line goes directly to the filter (inner portion of the filter and has to go through it in order to get anywhere else) and from there back into the frame. As far as salvaging the "good" fluid, I guess I could just drain all the fluid and when it starts to get cloudy, drain into a new bucket and discard that. I hate throwing out clear fluid... especially at almost $8/gallon. Thanks for you advice
I am not familiar with the filter you have, but most all oil filters have a bypass valve built into them. It is usually on the bottom of the filter media. A lot of systems have by-passes built into them. If the media becomes plugged with contaminates or the is very cold, it will allow the oil to flow through the filter thus protecting the engine or transmission from starving for oil. In regards to the clear oil, it may be OK, but you cannot see the microscopic contaminates (such as metal from gear wear). That is why I don't reuse it. If you are going to reuse the clear stuff I would advise you to at least run it through a paint strainer. I also pay over $8.00 a gallon, but it is going to be put in a system that could very well cost hundreds of dollars to repair if the oil contributes to component failure.
If the machine has been sitting for some time, I would change the oil and filter. Proper routine maintenance is the most economical way to prevent costly repairs. The pump and other hydraulic components are an expensive repair. Oil and grease are cheap and easy by comparison. If you have a shuttle, use the correct spec oil in it as well. The water will sit in the top layers of the reservoir so that's why its clear at the bottom. On the top of the lift towers on each side, there are plugs with breathers. Make sure they are in good condition as they lead right to the top of the oil. Cavitation from air in the system will make the oil look frothy, especially with any condensation in there. Once you have it running and used for some hours, another change is in order. There drain plugs in both frames, as well as vent plugs at the front. I advise the manuals for Operation and Repair. You can find Parts diagrams on the Case web site. The Operators Manual specifies a filter change after the first 20hrs and then 240hrs after. Hydraulic oil is after first 20 hrs and then at least every 500 after. The filter housing does have a bypass built into the head and it is desirable to change the filter before the bypass operates. I have owned my 580CK for 25 years and it has been trouble free except for the expected wear, tear and maintenance items. These are simple machines that will do all you can expect of something in the size and age. Jess
Petrochoice will vaccum dehydrate oils for 4.50$/gal. They said you would need 200 to 300 gal to make it work and run through the machine. I think they cover quite a bit of the USA. The way it sounds the oil is as good as new when they are done with it. FYI.
Water would accumulate at the lowest area of the oil reservoir and that is where the drains are located, each side, The suctions are up at the high point of the frames in front. If there was water in the system it would be right at the lower drains and you said the oil was clear there indicating absence of water, which would have run out before any oil if present. I'm thinking that you may have oil that is filled with air bubbles after running it due to insufficient fill or an oil which retains air. Good quality oils are designed to give up air rapidly. I would recommend Hy Tran Ultra from Case as a superior oil, and JD HyGard also acceptable as they have additives to get rid of air. There are undoubtedly others as well but I have used those two and can speak for them. You may do well to check all the clamps behind the grill on the suction tubes and pump inlet for tightness. Due to the way the Case frames are upswept to the front mounting bolts at the radiator wrapper even if you fill the reservoir to level there is still a big air pocket at the top of the front frames. That is why Case put the pipe plugs at the top of the frames up at the radiator, so that area could be bled after a reservoir fill, bleed off the front till the oil comes out there, then refill at the rear plug till both areas are full. this may have to be repeated a couple times till both areas are full. I have even had customers tell me how the hydraulics "firm up" and lose their sponginess after bled properly.