I am curious as to whether the return aux coupling has pressurized oil behind it? Reason for asking is that if I connect any attachment with a simple return line filter in the line the oil will blow out the filter seal, I have figured out it takes about a gallon to take a bath in hyd oil. The only explanation I can see it that the return coupler has charge pressure behind it and is when I operate the attachment I am forcing oil into the charge circuit and creating back pressure in the filter. Anybody have any thoughts on this? I am refering to the return coupler as the one that does not put out oil when the valve is in detent for continuos flow. Thanks for any help.
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I can see that being a possibility too, i guess a larger filter to handle higher flow rates? I agaree with you on the charge pressure, still i would have thought the filter seal could handle that pressure....
Good to know it takes that much oil to take a bath, just lucky it was not HOT oil or else you may have been deep fried!
Could it also possibly be pressure spikes from when the aux is turned on and off? as the fluid stops, it may still have momentum causing a spike? just a guess though, probably has nothing to do with it.
The spikes very well could be it. Probably need a much larger filter and refill with cooking oil too. I think the oil goes directly back to the reservoir and gets filtered so maybe a filter on the attachment is overkill too.
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The oil returning from the boom or auxiliary couplers is restricted before it return to the tank to create your charge oil pressure, so any filter in the charge oil circuit will have to be rated to take @ 250 psi.
It is redundant though as the skidsteer also filter that oil. Have you had the skidsteer filter off and seen how heavy it is. That's because it is rated for a higher pressure, burst is 1000 psi.
http://www.wixfilters.com/Lookup/PartDetails.aspx?Part=57404
that explains a lot and probably why the hydraulic filters cost so much also. Thanks Ken. The attachment I converted was the wood splitter which ran off one of those gear reduction hyd pumps you slide on the pto shaft. Not too impressed with the speed of the splitter now running off the skidsteer it is only half the speed of before. I never ran the tractor above a fast idle either but it was a big pump. I suppose I could run the pump with a hydraulic motor though.
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What diameter is the cylinder? Anything over a 4" bore is going to be slow to fill in my estimate, I have a 4" splitter, but also run it on high flow, so the machine is capable of 24 gpm reved up. Generally I find 1700 rpm makes it move fast enough. But if your splitter has a 5' bore the volume to fill the cylinder would be @ 30% higher.
Do you know what displacement the old pump is, and what pressure they run the system at? How long does it take to extend and retract and what is the stroke length
It is a 4inch cyl with 24 inch stroke and 2 inch dia rod. I checked it today and it takes 18 seconds full cycle with the skidstee at 1300 rpm. I havent found out the displacement of the old pump yet but I see them at northern hyd for about $1200 , it has 1 inch npt output fitting and 1 1/4 npt suction so it is intended to move quite a bit of oil. I think I will just settle for the 18 second cycle since I dont use all that much wood anymore anyway and it is handy to just be able to plug in the hoses and go.
