Another thing I gather from reading through some of the posts is a worry of contamination of your machines' hydraulic systems by renting and sharing and loaning attachments. I guess I probably take oil availability for granted, but I have on ocassion and when so ordered flushed attachments for our rental department and worried customers by uncoupling and opening a return line and with the machine at an idle, ran the return oil from the attachment into a bucket, then topped off the tank. Just run it 5 seconds or so. Unless it's a backhoe or something with big cylinders, its not a lot of oil, and ALL the old oil comes out. Just a thought.